---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Tue 01/11/11: 81 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:37 AM - Re: Please Check My Math (alum.wing strut) (Clif Dawson) 2. 04:10 AM - Re: Please Check My Math (alum.wing strut) (Jack Phillips) 3. 04:27 AM - Re: Re: Wing Strut Fork End (helspersew@aol.com) 4. 04:40 AM - Re: Re: Tail wheel (EDWARD BARCHIK) 5. 04:55 AM - Re: Re: Re: Wing Strut Fork End (Jack) 6. 05:05 AM - Re: Tail wheel (pineymb) 7. 05:36 AM - Re: Re: Wing Strut Fork End (Michael Perez) 8. 05:37 AM - Re: Please Check My Math (alum.wing strut) (Michael Perez) 9. 05:41 AM - Hey Jack Phillips... (Don Emch) 10. 05:41 AM - Re: Re: Re: Wing Strut Fork End (Michael Perez) 11. 06:04 AM - Re: Re: Re: Wing Strut Fork End (Michael Perez) 12. 06:08 AM - Re: Re: Wing Strut Fork End (Ryan Mueller) 13. 06:20 AM - Re: LG at last (TOM STINEMETZE) 14. 06:25 AM - Re: Re: Re: Wing Strut Fork End (Ryan Mueller) 15. 06:59 AM - Re: Re: Wing Strut Fork End (Kip and Beth Gardner) 16. 07:13 AM - Re: Re: Wing Strut Fork End (hvandervoo@aol.com) 17. 07:16 AM - Re: steel (DOMIT) 18. 07:26 AM - Re: LG at last (hvandervoo@aol.com) 19. 07:36 AM - BPA article (Douwe Blumberg) 20. 07:36 AM - Re: Corvair Valve issue (shad bell) 21. 07:47 AM - Re: LG at last (Don Emch) 22. 07:47 AM - Hole Depth for Piper fork (Michael Perez) 23. 07:49 AM - Re: Please Check My Math (alum.wing strut) (Doug Dever) 24. 07:51 AM - Re: Re: Wing Strut Fork End (AMsafetyC@aol.com) 25. 07:53 AM - 4130 tubing (Douwe Blumberg) 26. 07:53 AM - Re: Re: Wing Strut Fork End (Doug Dever) 27. 07:56 AM - Re: Re: Wing Strut Fork End (Michael Perez) 28. 08:04 AM - Re: LG at last (TOM STINEMETZE) 29. 08:27 AM - Re: Re: LG at last (Kip and Beth Gardner) 30. 08:28 AM - Re: Re: Tail wheel (EDWARD BARCHIK) 31. 08:49 AM - wing strut fork ends (Lawrence Williams) 32. 09:05 AM - Re: wing strut fork ends (Ryan Mueller) 33. 09:07 AM - Re: Re: Wing Strut Fork End (Michael Perez) 34. 09:24 AM - Re: Re: Wing Strut Fork End (Kip and Beth Gardner) 35. 09:25 AM - Re: Please Check My Math (alum.wing strut) (Ray Krause) 36. 09:46 AM - Re: Please Check My Math (alum.wing strut) (Charles Campbell) 37. 09:56 AM - Re: wing strut fork ends (KM Heide CPO/FAAOP) 38. 10:05 AM - Re: Re: Corvair Challenges and 5th Bearing (Rick Holland) 39. 10:09 AM - Re: steel (Rick Holland) 40. 10:11 AM - Re: Re: Corvair Challenges and 5th Bearing (Charles Campbell) 41. 10:23 AM - Re: wing strut fork ends (airlion) 42. 10:23 AM - Re: Please Check My Math (alum.wing strut) (Charles Campbell) 43. 10:26 AM - Re: Re: LG at last (Rick Holland) 44. 10:28 AM - Re: BPA article (K5YAC) 45. 10:33 AM - Re: Please Check My Math (alum.wing strut) (Charles Campbell) 46. 10:36 AM - Re: Hole Depth for Piper fork (Rick Holland) 47. 10:43 AM - Re: Re: Tail wheel (Rick Holland) 48. 10:49 AM - Re: wing strut fork ends (DOMIT) 49. 10:51 AM - Re: wing strut fork ends (Charles Campbell) 50. 10:53 AM - Re: RV10-List: Airfoil Drag Video... (DOMIT) 51. 11:02 AM - Wing Strut Fork End Concerns (BYD) 52. 11:09 AM - Re: 4130 tubing (K5YAC) 53. 11:41 AM - Re: Hole Depth for Piper fork (Michael Perez) 54. 11:41 AM - Re: wing strut fork ends (Rick Holland) 55. 11:41 AM - Re: Wing Strut Fork End Concerns (Ryan Mueller) 56. 11:41 AM - Re: Re: 4130 tubing (Kenneth Bickers) 57. 12:07 PM - Re: Re: Wing Strut Fork End (Doug Dever) 58. 12:47 PM - Re: Please Check My Math (alum.wing strut) (Doug Dever) 59. 12:53 PM - Re: Wing Strut Fork End Concerns (BYD) 60. 01:03 PM - Re: Wing Strut Fork End Concerns (DOMIT) 61. 01:36 PM - Re: Re: 4130 tubing (shad bell) 62. 01:59 PM - Re: wing strut fork ends (gtche98) 63. 04:06 PM - Re: Wing Strut Fork End (Bill Church) 64. 04:27 PM - Re: LG at last (Ben Charvet) 65. 05:02 PM - Re: Please Check My Math (alum.wing strut) (gliderx5@comcast.net) 66. 05:14 PM - Re: Re: Wing Strut Fork End (Kenneth Howe) 67. 06:08 PM - Adjustable Wood Wing Strut Fitting (Michael Perez) 68. 06:56 PM - Re: Tail wheel (blue213) 69. 07:14 PM - Re: Re: Wing Strut Fork End (Greg Cardinal) 70. 07:14 PM - Re: steel (Ernie Moreno) 71. 07:14 PM - Re: Re: 4130 tubing (Ernie Moreno) 72. 07:35 PM - Re: 4130 tubing (Piet2112) 73. 07:55 PM - Re: Adjustable Wood Wing Strut Fitting (TOM MICHELLE BRANT) 74. 08:02 PM - Re: Adjustable Wood Wing Strut Fitting (Kip and Beth Gardner) 75. 08:18 PM - Re: Adjustable Wood Wing Strut Fitting (DOMIT) 76. 08:21 PM - Re: Please Check My Math (alum.wing strut) (Clif Dawson) 77. 08:22 PM - Re: Adjustable Wood Wing Strut Fitting (Owen Davies) 78. 08:22 PM - Re: Wing Strut Fork End (DOMIT) 79. 08:41 PM - Re: Adjustable Wood Wing Strut Fitting (amsafetyc@aol.com) 80. 09:10 PM - Re: Adjustable Wood Wing Strut Fitting (Owen Davies) 81. 10:31 PM - Re: BPA article (bubbleboy) ________________________________ Message 1 _____________________________________ Time: 01:37:17 AM PST US From: "Clif Dawson" Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) Attached is the lift distribution chart for hershey bar wings in the aspect ratio range of the Piet wing. From this you can deduce that there is only a small portion of the lift supported by the cabanes. Therefore, the majority of lift is handled by the struts. It's all in the archives, back there somewhere. :-) Also, my understanding is that one designs and builds to a safety factor of 1.5. So if an AC is placarded at 4G then it will go to 6 before failure. Clif It has to do with the distribution of lift. More lift is generated from the inboard section of the wing than the outboard sections. As a result there is less torque upward on the outer wing panels than if the lift was equal all of the way across the wing. This means that there is less force imposed on the lift strut. Malcolm Morrison http://home.comcast.net/~mmorrison123/ What in your math is different then Jack's 3200? Your numbers are quite different? Michael Perez ________________________________ Message 2 _____________________________________ Time: 04:10:19 AM PST US From: "Jack Phillips" Subject: RE: Pietenpol-List: Please Check My Math (alum.wing strut) This is spanwise lift. What I was trying to approximate is the chordwise pressure distribution ' that will determine how much load is carried by the front strut compared to the rear strut. Since the center of pressure is located very close to the center of gravity (and hopefully a little bit forward of it, unless the plane is too tail-heavy), it is loacted very close to the front spar, which means the front spar carries the lion=92s share of the lift load. My guess was that it carrries 2/3 of the load and the rear spars only 1/3, but this is only a GUESS. It may be carrying much more of the load than that. It might be carrying =BE of the load. Because you don=92t know, you look at what has worked in the past. If you were a real aircraft factory, the prudent thing to do would be to build the plane with turnbuckle fittings, and then intentionally load it until it breaks and see what that value was. Then divide that value by 1.5 and call that your max safe G load. In Michael=92s case, the best thing to do is to build his plane with the cheap fittings, then load it to gross weight and subject it to maneuvers which induce 6 G=92s and see if he dies in the test. If he doesn=92t die, then it was OK. Jack Phillips NX899JP =93Icarus Plummet=94 Raleigh, NC _____ From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of Clif Dawson Sent: Tuesday, January 11, 2011 4:35 AM Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) Attached is the lift distribution chart for hershey bar wings in the aspect ratio range of the Piet wing. From this you can deduce that there is only a small portion of the lift supported by the cabanes. Therefore, the majority of lift is handled by the struts. It's all in the archives, back there somewhere. :-) Also, my understanding is that one designs and builds to a safety factor of 1.5. So if an AC is placarded at 4G then it will go to 6 before failure. Clif It has to do with the distribution of lift. More lift is generated from the inboard section of the wing than the outboard sections. As a result there is less torque upward on the outer wing panels than if the lift was equal all of the way across the wing. This means that there is less force imposed on the lift strut. Malcolm Morrison http://home.comcast.net/~mmorrison123/ What in your math is different then Jack's 3200? Your numbers are quite different? Michael Perez ________________________________ Message 3 _____________________________________ Time: 04:27:23 AM PST US Subject: Re: Pietenpol-List: Re: Wing Strut Fork End From: helspersew@aol.com Michael, If you are hell-bent on trying them, then do so. Nobody is going to stop yo u, and you can prove us all wrong.....................until the end. Dan Helsper Poplar Grove, IL. -----Original Message----- From: Michael Perez Sent: Mon, Jan 10, 2011 8:50 pm Subject: RE: Pietenpol-List: Re: Wing Strut Fork End et> I understand what everyone is saying...stop screwing around and use what is nown to work. But No one has explained why the fittings I propose are not a ood substitute. If the strength is there, then why not? I don't believe tha t ven the -80 fittings, (8000# rating) are not good enough. What if there wer e nother fork available, rated at say, 5000# and it was called a wing strut ork...would any one have an issue then? Again, sorry for the rant. ichael Perez aretaker Aero ww.karetakeraero.com -- On Mon, 1/10/11, Jack Phillips wrote: > From: Jack Phillips Subject: RE: Pietenpol-List: Re: Wing Strut Fork End To: pietenpol-list@matronics.com Date: Monday, January 10, 2011, 9:00 PM --> Pietenpol-List message posted by: "Jack Phillips" Remember, that 3200 lbs I calculated had NO safety factor in it. That means, if you hit a 4 G bump in turbulance and you're flying at gross weight, you can expect complete failure instantly. Nobody designs a critical component with no safety factor. There are places to cut costs, and there are places to be very conservative. This is not a place to take risks. Even though you fly in Ohio and fields for forced landings are plentiful, they do no good if you are plunging to earth in your fuselage, looking up at your wing fluttering down lazily above you, due to cheap fittings letting go. Jack Phillips NX899JP "Icarus Plummet" Raleigh, NC -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of Michael Perez Sent: Monday, January 10, 2011 8:29 PM To: pietenpol-list@matronics.com Subject: Re: Pietenpol-List: Re: Wing Strut Fork End I understand the concern. What I don't understand are the ratings for the forks. If the turnbuckle assembly is rated at 4600#, then every component that makes up that assembly must be able to handle 4600#. ( Even the brass barrel...which surprises me. We should use brass bolts everywhere...) According to an earlier post I submitted, Jack Phillips calculated a 4G fitting load of 3200#. The 5/16" threaded turnbuckle fork is rated at 4600#, why the need to use something that is twice as much? (The 7/16" Piper fork) I don't see a need to use a fitting with twice the load capability over a 4600# fitting. Having said all that, there must be reasons everyone uses the Piper fork...I just don't understand why...because that is just what is used? As I said there are larger forks...the -80 are rated at 8000#. I'm not trying to give anyone a hard time here, just trying to understand the logic. Michael Perez Karetaker Aero www.karetakeraero.com Email Forum - FAQ, - MATRONICS WEB FORUMS - List Contribution Web Site - -Matt Dralle, List Admin. -======================== -= - The Pietenpol-List Email Forum - -= Use the Matronics List Features Navigator to browse -= the many List utilities such as List Un/Subscription, -= Archive Search & Download, 7-Day Browse, Chat, FAQ, -= Photoshare, and much much more: - -= --> http://www.matronics.com/Navigator?Pietenpol-List - -======================== -= - MATRONICS WEB FORUMS - -= Same great content also available via the Web Forums! - -= --> http://forums.matronics.com - -======================== -= - List Contribution Web Site - -= Thank you for your generous support! -= -Matt Dralle, List Admin. -= --> http://www.matronics.com/contribution -======================== ________________________________ Message 4 _____________________________________ Time: 04:40:17 AM PST US From: EDWARD BARCHIK Subject: RE: Pietenpol-List: Re: Tail wheel Rick, This is a woodshop class. The students are 3rd and 4th year students, Juniors and Seniors. We hope to complete project in spring 2012. Ed ________________________________ From: owner-pietenpol-list-server@matronics.com [owner-pietenpol-list-serve r@matronics.com] on behalf of Rick Holland [at7000ft@gmail.com] Sent: Monday, January 10, 2011 6:40 PM Subject: Re: Pietenpol-List: Re: Tail wheel That's the same one I have Charles. Used with a used J3 two piece leaf spri ng I got off ebay. rick On Mon, Jan 10, 2011 at 3:31 PM, Charles Campbell > wrote: Rick, what model Matco tailwheel did you use? I am thinking about a Matco WHLT-6. The specs say it has an operating load of 450#. ----- Original Message ----- From: Rick Holland Sent: Monday, January 10, 2011 4:09 PM Subject: Re: Pietenpol-List: Re: Tail wheel I used a Matco, much lighter and cheaper than a Scott: http://www.matcomfg.com/TailWheelAssemblies-tp2-13.html On Mon, Jan 10, 2011 at 11:49 AM, Earnest Bunbury > wrote: We've used both a Maule and a Scott, both 6-in., full-swivel, steerable, wi th detent. The Scott came with the plane and was a bit squirrelly. The Maul e was a gift from one of the guys at the field. It works "better" but both of them are heavy and way over-engineered for the purpose. If you're going with a new set-up, I would buy the lightest that can handle the load or bui ld from scratch. There are some cool solutions out there, some of which are shown at westcoastpiet, as Kevin mentioned. What sort of class are the kids in? Is this a shop class or an aviation-ori ented class? Good luck and keep us updated! " target="_blank">http://www.matronics.com/Navigator?Pietenpol-List tp://forums.matronics.com _blank">http://www.matronics.com/contribution -- Rick Holland Castle Rock, Colorado "Logic is a wreath of pretty flowers, that smell bad" href="http://www.matronics.com/Navigator?Pietenpol-List">http://www.matro nics.com/Navigator?Pietenpol-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c " target="_blank">http://www.matronics.com/Navigator?Pietenpol-List tp://forums.matronics.com _blank">http://www.matronics.com/contribution -- Rick Holland Castle Rock, Colorado "Logic is a wreath of pretty flowers, that smell bad" Email secured by Check Point ________________________________ This message (including any attachments) is intended only for the use of th e individual or entity to which it is addressed and may contain information that is non-public, proprietary, privileged, confidential, and exempt from disclosure under applicable law or may constitute as attorney work product . If you are not the intended recipient, you are hereby notified that any u se, dissemination, distribution, or copying of this communication is strict ly prohibited. If you have received this communication in error, notify us immediately by telephone and (i) destroy this message if a facsimile or (ii ) delete this message immediately if this is an electronic communication. Thank you. Berwick Area School District ________________________________ Message 5 _____________________________________ Time: 04:55:30 AM PST US From: "Jack" Subject: RE: Re: Pietenpol-List: Re: Wing Strut Fork End Just to be sure what we are discussing, the AN 665-80RA (picture is a 21) is a no-no for wing struts. Jack DSM _____ From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of helspersew@aol.com Sent: Tuesday, January 11, 2011 6:25 AM Subject: Re: Pietenpol-List: Re: Wing Strut Fork End Michael, If you are hell-bent on trying them, then do so. Nobody is going to stop you, and you can prove us all wrong.....................until the end. Dan Helsper Poplar Grove, IL. -----Original Message----- From: Michael Perez Sent: Mon, Jan 10, 2011 8:50 pm Subject: RE: Pietenpol-List: Re: Wing Strut Fork End I understand what everyone is saying...stop screwing around and use what is known to work. But No one has explained why the fittings I propose are not a good substitute. If the strength is there, then why not? I don't believe that even the -80 fittings, (8000# rating) are not good enough. What if there were another fork available, rated at say, 5000# and it was called a wing strut fork...would any one have an issue then? Again, sorry for the rant. Michael Perez Karetaker Aero www.karetakeraero.com --- On Mon, 1/10/11, Jack Phillips wrote: > From: Jack Phillips > Subject: RE: Pietenpol-List: Re: Wing Strut Fork End > To: pietenpol-list@matronics.com > Date: Monday, January 10, 2011, 9:00 PM > --> Pietenpol-List message posted > by: "Jack Phillips" > > Remember, that 3200 lbs I calculated had NO safety factor > in it. That > means, if you hit a 4 G bump in turbulance and you're > flying at gross > weight, you can expect complete failure instantly. > > Nobody designs a critical component with no safety > factor. There are places > to cut costs, and there are places to be very > conservative. This is not a > place to take risks. Even though you fly in Ohio and > fields for forced > landings are plentiful, they do no good if you are plunging > to earth in your > fuselage, looking up at your wing fluttering down lazily > above you, due to > cheap fittings letting go. > > Jack Phillips > NX899JP "Icarus Plummet" > Raleigh, NC > > -----Original Message----- > From: owner-pietenpol-list-server@matronics.com > [mailto:owner-pietenpol-list-server@matronics.com ] > On Behalf Of Michael > Perez > Sent: Monday, January 10, 2011 8:29 PM > To: pietenpol-list@matronics.com > Subject: Re: Pietenpol-List: Re: Wing Strut Fork End > > > > I understand the concern. What I don't understand are the > ratings for the > forks. If the turnbuckle assembly is rated at 4600#, then > every component > that makes up that assembly must be able to handle 4600#. ( > Even the brass > barrel...which surprises me. We should use brass bolts > everywhere...) > According to an earlier post I submitted, Jack Phillips > calculated a 4G > fitting load of 3200#. > > The 5/16" threaded turnbuckle fork is rated at 4600#, why > the need to use > something that is twice as much? (The 7/16" Piper fork) > > I don't see a need to use a fitting with twice the load > capability over a > 4600# fitting. > > Having said all that, there must be reasons everyone uses > the Piper fork...I > just don't understand why...because that is just what is > used? > > As I said there are larger forks...the -80 are rated at > 8000#. > > I'm not trying to give anyone a hard time here, just trying > to understand > the logic. > > Michael Perez > Karetaker Aero > www.karetakeraero.com > > > > > > > > Email Forum - > FAQ, > - MATRONICS WEB FORUMS - > List Contribution Web Site - > -Matt > Dralle, List Admin. > > > > " target=_blank>http://www.matronics.com/Navigator?Pietenpol-List p://forums.matronics.com blank>http://www.matronics.com/contribution ________________________________ Message 6 _____________________________________ Time: 05:05:45 AM PST US Subject: Pietenpol-List: Re: Tail wheel From: "pineymb" The setup I used was a Matco tailwheel AS&S PN# 06-01615 and single leaf spring PN# 06-14500. Untested but I think will work fine and relatively inexpensive. -------- Adrian M Winnipeg, MB Canada Read this topic online here: http://forums.matronics.com/viewtopic.php?p=326471#326471 Attachments: http://forums.matronics.com//files/dscn0057_988.jpg http://forums.matronics.com//files/dsc00081_959.jpg ________________________________ Message 7 _____________________________________ Time: 05:36:56 AM PST US From: Michael Perez Subject: Re: Pietenpol-List: Re: Wing Strut Fork End Ah, yeah, I read all posts related to my original question. This safety factor of 3, is that a standard factor or a number you came up with Bill? Michael Perez Karetaker Aero www.karetakeraero.com ________________________________ Message 8 _____________________________________ Time: 05:37:17 AM PST US From: Michael Perez Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) Thanks Cliff. My understanding as with you, (and I BELIEVE the way things a re designed here at work) is to use a safety factor of 1.5. That is why I q uestioned the factor of 3 posted earlier. Using my original post and Jack P's calculated 3200# with a safety factor o f 1.5 that would be 4800#. Anyone know of a Pietenpol seeing 6 Gs? Michael Perez =0AKaretaker Aero =0Awww.karetakeraero.com --- On Tue, 1/11/11, Clif Dawson wrote: From: Clif Dawson Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) =EF=BB=0A=0A =0A#yiv805611046 P {=0AMARGIN:0px;}=0A=0A=0AAttached is the lift distribution chart for hershey bar =0Awings in the aspect ratio=0Aran ge of the Piet wing. From this you can deduce that =0Athere is only a small =0Aportion of the lift supported by the cabanes. Therefore, =0Athe majority of=0Alift is handled by the struts. It's all in the archives, =0Aback ther e somewhere. :-)=0A=C2-=0AAlso, my understanding is that one designs and builds to a =0Asafety factor=0Aof 1.5. So if an AC is placarded at 4G then it will go to =0A6 before failure.=0A=C2-=0AClif=0A=0A =0A It has to do =0A with the distribution of lift.=C2- More lift is ge nerated from the inboard =0A section of the wing than the outboard section s.=C2- As a result there is =0A less torque upward on the outer wing pan els than if the lift was equal all of =0A the way across the wing.=C2- T his means that there is less force imposed on =0A the lift strut.=C2- Ma lcolm Morrison http://home.comcast.net/~mmorrison123/ =0A What in your =0A math is different then Jack's 3200? Your numbers are quite =0A different? Michael Perez ________________________________ Message 9 _____________________________________ Time: 05:41:17 AM PST US Subject: Pietenpol-List: Hey Jack Phillips... From: "Don Emch" Hey Jack... could you email me at WingWright@gmail.com Thanks, Don Emch NX899DE do not archive Read this topic online here: http://forums.matronics.com/viewtopic.php?p=326477#326477 ________________________________ Message 10 ____________________________________ Time: 05:41:36 AM PST US From: Michael Perez Subject: RE: Re: Pietenpol-List: Re: Wing Strut Fork End Negative. Turnbuckle assemblies.The -46 are rated at 4600#, the -61 at 6100# and the -80 at 8000#. Each component in those assemblies must be rated at least as good as the entire assembly. So the AN 161 forks, the -80 are rated to 8000#. Michael Perez Karetaker Aero www.karetakeraero.com ________________________________ Message 11 ____________________________________ Time: 06:04:42 AM PST US From: Michael Perez Subject: RE: Re: Pietenpol-List: Re: Wing Strut Fork End I see the points of a few on this list and laugh at some of the others, but I appreciate those who take the time to explain their points of view and t ake the time to listen to mine. I may ask around here at work and what peop le think. If I find any good intell. along the way, I'll post it. By the way, anyone know what the Piper forks are rated at? What material? I could not find anything on them.- Michael Perez =0AKaretaker Aero =0Awww.karetakeraero.com ________________________________ Message 12 ____________________________________ Time: 06:08:22 AM PST US Subject: Re: Pietenpol-List: Re: Wing Strut Fork End From: Ryan Mueller It has been explained to you why you should use purpose built wing struts forks. Use the right tool for the right job. And you use the right tool for the right job because you want to go out and safely fly and enjoy your airplane without having to be concerned about ending up as a smoking hole in the ground, leaving your wife a widower and your children fatherless.....or god forbid hurt anyone else. Any obsession with making your Piet the "snowflakiest" of them all should not trump safety. Just do it right.....so we can drop this discussion already. :) Ryan On Mon, Jan 10, 2011 at 7:29 PM, Michael Perez wrote: > speedbrake@sbcglobal.net> > > I'm not trying to give anyone a hard time here, just trying to understand > the logic. > > Michael Perez > Karetaker Aero > www.karetakeraero.com > > ________________________________ Message 13 ____________________________________ Time: 06:20:05 AM PST US From: "TOM STINEMETZE" Subject: Re: Pietenpol-List: LG at last Ben: I purchased the spring struts with springs from Ken Perkins in Olathe, KS. They came with the fork made up on one end. You adjust to the length needed and make your own fork on the opposite end. Takes a mighty good vice or other type of compressive device to squeeze the die springs sufficiently to assemble them. I could not tell that they compressed at all with me sitting in the plane and no engine on the front. Tom N328X >>> Ben Charvet 1/10/2011 7:07 PM >>> I'm thinking of replacing my bungees with springs like you have. Did you make the spring struts yourself, or buy them ready made? Ben Charvet NX866BC ________________________________ Message 14 ____________________________________ Time: 06:25:31 AM PST US Subject: Re: Re: Pietenpol-List: Re: Wing Strut Fork End From: Ryan Mueller Give Wag-Aero a call, they manufacture them: http://www.wagaero.com/contact.html On Tue, Jan 11, 2011 at 8:01 AM, Michael Perez wrote: > I see the points of a few on this list and laugh at some of the others, but > I appreciate those who take the time to explain their points of view and > take the time to listen to mine. I may ask around here at work and what > people think. If I find any good intell. along the way, I'll post it. > > By the way, anyone know what the Piper forks are rated at? What material? I > could not find anything on them. > > Michael Perez > Karetaker Aero > www.karetakeraero.com > > > * > > * > > ________________________________ Message 15 ____________________________________ Time: 06:59:27 AM PST US From: Kip and Beth Gardner Subject: Re: Pietenpol-List: Re: Wing Strut Fork End While we're on this topic, does anyone know of a way to make wooden lift struts adjustable? I'm going to make mine from some # of laminations, with at least one layer of carbon fiber strands within the full strut, and probably cross-wise layerings for extra reinforcement at the ends (still figuring out the details, but similar to what Jim Markle did on his cabana struts). =46rom the images I've found on various people's sites so far, it looks like the only option for adjustment would be to remake the terminal fittings, and I imagine there's a practical length limit with regard to twisting loads (?) on those. If adjustment is difficult or impossible (short of making new struts), I'd think I'd want to put this off until just about everything else is completed and I'm working on the initial rigging of the completed wings? Any comments? Thanks! Kip Gardner On Jan 11, 2011, at 9:14 AM, Ryan Mueller wrote: > Give Wag-Aero a call, they manufacture them: > > http://www.wagaero.com/contact.html > > On Tue, Jan 11, 2011 at 8:01 AM, Michael Perez wrote: > I see the points of a few on this list and laugh at some of the others, but I appreciate those who take the time to explain their points of view and take the time to listen to mine. I may ask around here at work and what people think. If I find any good intell. along the way, I'll post it. > > By the way, anyone know what the Piper forks are rated at? What material? I could not find anything on them. > > Michael Perez > Karetaker Aero > www.karetakeraero.com > > > > > " target="_blank">http://www.matronics.com/Navigator?Pietenpol-List > tp://forums.matronics.com > _blank">http://www.matronics.com/contribution > > > > > ________________________________ Message 16 ____________________________________ Time: 07:13:16 AM PST US Subject: Re: Pietenpol-List: Re: Wing Strut Fork End From: hvandervoo@aol.com There are 3 factors that decide selection of the Fork-end of the main strut : 1) tension load, easily understood and both J-3 fork end and a Turnbuckle s tyle fork can handle the required load. 2) compression load, often over looked but flying in turbulence often exper ienced, J-3 fork can handle this, Turnbuckle style can not. Remember that turnbuckles are designed for cable use, no compression loads there. 3) overlooked even more often is thread strength, diameter & length. For a steel fork end to work as designed the diameter should be same a as t he height of the nut insert (nut part to be of the same material) In other words a 5/16 Fork tread needs to have 5/16 nut height, if you tap in to the strut your tread dept needs to be at least 5/16. Note: nut/ strut threads of the same steel material, more length is always better, rolled threads are better than cut/ tapped threads. I use the J-3 style fork end with steel struts and the weld-in treaded purp ose build nut insert. Now if you choose to use aluminum struts and tap your own treads be aware t hat aluminum has a lower tensile strength than steel. So compensate by tapping a deep/ long thread in to the best aluminum you ca n get. Your fork tread might not be long enough. You might need to consider a steel insert. Turnbuckles assemblies with brass center piece use the same principle, the tread depth is much longer ( 6-8 X ) than the diameter of the tread. I did not sleep in a Holiday-inn express last night, but am a mechanical en gineer by profession Hans NX15KV ________________________________ Message 17 ____________________________________ Time: 07:16:04 AM PST US Subject: Pietenpol-List: Re: steel From: "DOMIT" VERY COOL! What are you powering them with? How far along are you? Got pics? I'm currently messing with plans (with a highly qualified professional doing all the real brain-work... I just throw ideas at him and see what sticks!) for a 75% scale Albatros. Current plan is to use a Model A (or B) with some "power enhancement" (Not just a stock engine!) for power. -------- Brad "DOMIT" Smith First rule of ground school: This is the ground... don't hit it going fast. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=326503#326503 ________________________________ Message 18 ____________________________________ Time: 07:26:24 AM PST US Subject: Re: Pietenpol-List: LG at last From: hvandervoo@aol.com You need to preload a little, 1/2 - 1/4 inch Or landing gear will be ratteling in the breeze up there. Hans NX15KV -----Original Message----- From: Jack Sent: Mon, Jan 10, 2011 9:33 pm Subject: RE: Re: Pietenpol-List: LG at last Rick, You mentioned pre-loaddo you mean compress the spring =C2=BD inch when assembled? For my springs that would be a bunch of pressure. Thanks, Jack DSM From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-lis t-server@matronics.com] On Behalf Of Rick Holland Sent: Monday, January 10, 2011 8:08 PM Subject: Re: Pietenpol-List: LG at last I used the attached design for mine using die springs that can be ordered o nline. Remember to pre-load the spring by half and inch or so. rick On Mon, Jan 10, 2011 at 6:07 PM, Ben Charvet wrote: I'm thinking of replacing my bungees with springs like you have. Did you m ake the spring struts yourself, or buy them ready made? Ben Charvet NX866BC On 1/10/2011 5:09 PM, TOM STINEMETZE wrote: Well it's kind of bittersweet since I already know that this set of landing gear will have to be rebuilt before the plane gets to move much. BUT it's still a grand feeling to have N328X up on its gear at last. There is just something about being able to swing a leg up and sit with your back firmly settled into the seat and everything pointing UP! Now I can start install ing a lot of those things that have been occupying shelf space and looking for a home. My wife had to call me in to supper several times before I could bring myse lf to vacate that seat. A'course some of the was due to the fact that I co uldn't figure out what to grab to get me standing back up again. Ken Perkins hubs and spring shocks; spokes from Buchanans; 19" aluminum rim s from a local cycle shop; weldable axles from AS&S; brake calipers from su rplus Honda Shadow; brake disks my design from a local machine shop; brake brackets from my son in CA. Truely a "melting pot" project. Oh, and my ow n ugly welding on everything. Tom Stinemetze N328X " target="_blank">http://www.matronics.com/Navigator?Pietenpol-List tp://forums.matronics.com _blank">http://www.matronics.com/contribution -- Rick Holland Castle Rock, Colorado "Logic is a wreath of pretty flowers, that smell bad" -= - The Pietenpol-List Email Forum - -= Use the Matronics List Features Navigator to browse -= the many List utilities such as List Un/Subscription, -= Archive Search & Download, 7-Day Browse, Chat, FAQ, -= Photoshare, and much much more: - -= --> http://www.matronics.com/Navigator?Pietenpol-List - -======================== -= - MATRONICS WEB FORUMS - -= Same great content also available via the Web Forums! - -= --> http://forums.matronics.com - -======================== -= - List Contribution Web Site - -= Thank you for your generous support! -= -Matt Dralle, List Admin. -= --> http://www.matronics.com/contribution -======================== ________________________________ Message 19 ____________________________________ Time: 07:36:14 AM PST US From: "Douwe Blumberg" Subject: Pietenpol-List: BPA article This last issue of the BPA (Brodhead Pietenpol Association) newsletter was excellent. Not only was William Wynn's article great, but Frank Pavliga's was excellent too as he brings us through the evolution of 899FP with three different engines, very insightful!! Let's all support the BPA's efforts and simply join up and get ALL the great articles throughout the year. Douwe ________________________________ Message 20 ____________________________________ Time: 07:36:49 AM PST US From: shad bell Subject: Re: Pietenpol-List: Corvair Valve issue Kevin, Check the intake valves for lead build up, (it might help)-we have had this a couple times with 100 LL.- We were able to lap the valve with out pulling the head, thru the spark plug hole.- Just need to pull the va lve keeper off and get some valve compound.- Are you still planning on go ing to Brodhead this year?- Looking forward to meeting the Mighty Axle Pu rtee, and his Fat Bottom Girl. - Shad =0A=0A=0A ________________________________ Message 21 ____________________________________ Time: 07:47:24 AM PST US Subject: Pietenpol-List: Re: LG at last From: "Don Emch" Looks great Tom... maybe a tad taller than mine. What a great feeling for you! I've come very close to pulling my bungees and replacing with springs. But, I think I finally found a way to get the bungees tight enough with a come-along... and lots of cussing. Don Emch NX899DE Read this topic online here: http://forums.matronics.com/viewtopic.php?p=326509#326509 ________________________________ Message 22 ____________________________________ Time: 07:47:24 AM PST US From: Michael Perez Subject: Pietenpol-List: Hole Depth for Piper fork Since I will be welding my steel straps onto my landing gear fittings, I need to pre-drill the hole for the wing strut fork. How deep from the edge of the fitting does the hole need to be so that the Piper fork will fit? I assume the standard 2X bolt diameter will work, but I want to be sure prior to drilling and welding. Michael Perez Karetaker Aero www.karetakeraero.com ________________________________ Message 23 ____________________________________ Time: 07:49:33 AM PST US From: Doug Dever Subject: RE: Pietenpol-List: Please Check My Math (alum.wing strut) The center of pressure moves quite a bit with angle of attack also. At a 0 or slightly negative angle of attack the load may approach 50/50 and at a high angle of attack may approach 95% being carried by the front spar. Cen ter of pressure movement varies with airfoil shape too. Too many variables for me to fool with. Doug Dever In beautiful Stow Ohio From: pietflyr@bellsouth.net Subject: RE: Pietenpol-List: Please Check My Math (alum.wing strut) This is spanwise lift. What I was trying to approximate is the chordwise p ressure distribution ' that will determine how much load is carried by th e front strut compared to the rear strut. Since the center of pressure is located very close to the center of gravity (and hopefully a little bit for ward of it=2C unless the plane is too tail-heavy)=2C it is loacted very clo se to the front spar=2C which means the front spar carries the lion=92s sha re of the lift load. My guess was that it carrries 2/3 of the load and the rear spars only 1/3=2C but this is only a GUESS. It may be carrying much more of the load than that. It might be carrying =BE of the load. Because you don=92t know=2C you look at what has worked in the past. If yo u were a real aircraft factory=2C the prudent thing to do would be to build the plane with turnbuckle fittings=2C and then intentionally load it until it breaks and see what that value was. Then divide that value by 1.5 and call that your max safe G load. In Michael=92s case=2C the best thing to do is to build his plane with the cheap fittings=2C then load it to gross weight and subject it to maneuvers which induce 6 G=92s and see if he dies in the test. If he doesn=92t die =2C then it was OK. Jack Phillips NX899JP =93Icarus Plummet=94 Raleigh=2C NC From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-lis t-server@matronics.com] On Behalf Of Clif Dawson Sent: Tuesday=2C January 11=2C 2011 4:35 AM Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) Attached is the lift distribution chart for hershey bar wings in the aspect ratio range of the Piet wing. From this you can deduce that there is only a small portion of the lift supported by the cabanes. Therefore=2C the majority of lift is handled by the struts. It's all in the archives=2C back there somew here. :-) Also=2C my understanding is that one designs and builds to a safety factor of 1.5. So if an AC is placarded at 4G then it will go to 6 before failure. Clif It has to do with the distribution of lift. More lift is generated from th e inboard section of the wing than the outboard sections. As a result ther e is less torque upward on the outer wing panels than if the lift was equal all of the way across the wing. This means that there is less force impos ed on the lift strut. Malcolm Morrison http://home.comcast.net/~mmorrison123/ What in your math is different then Jack's 3200? Your numbers are quite dif ferent? Michael Perez ________________________________ Message 24 ____________________________________ Time: 07:51:30 AM PST US From: AMsafetyC@aol.com Subject: Re: Pietenpol-List: Re: Wing Strut Fork End When you find that out I would like to know all the details and pics, I already have my wooden struts and have been trying to come up with an attachment method or design that's going to be safe and work well. So please share your results. Thanks John In a message dated 1/11/2011 9:59:49 A.M. Eastern Standard Time, kipandbeth@earthlink.net writes: While we're on this topic, does anyone know of a way to make wooden lift struts adjustable? I'm going to make mine from some # of laminations, with at least one layer of carbon fiber strands within the full strut, and probably cross-wise layerings for extra reinforcement at the ends (still figuring out the details, but similar to what Jim Markle did on his cabana struts). From the images I've found on various people's sites so far, it looks like the only option for adjustment would be to remake the terminal fittings, and I imagine there's a practical length limit with regard to twisting loads (?) on those. If adjustment is difficult or impossible (short of making new struts), I'd think I'd want to put this off until just about everything else is completed and I'm working on the initial rigging of the completed wings? Any comments? Thanks! Kip Gardner On Jan 11, 2011, at 9:14 AM, Ryan Mueller wrote: Give Wag-Aero a call, they manufacture them: _http://www.wagaero.com/contact.html_ (http://www.wagaero.com/contact.html) On Tue, Jan 11, 2011 at 8:01 AM, Michael Perez <_speedbrake@sbcglobal.net_ (mailto:speedbrake@sbcglobal.net) > wrote: I see the points of a few on this list and laugh at some of the others, but I appreciate those who take the time to explain their points of view and take the time to listen to mine. I may ask around here at work and what people think. If I find any good intell. along the way, I'll post it. By the way, anyone know what the Piper forks are rated at? What material? I could not find anything on them. Michael Perez Karetaker Aero _www.karetakeraero.com_ (http://www.karetakeraero.com/) " target="_blank">http://www.matronics.com/Navigator?Pietenpol-List _tp://forums.matronics.com_ (tp://forums.matronics.com/) _blank">http://www.matronics.com/contribution href="http://www.matronics.com/Navigator?Pietenpol-List">http://www.matronics.com/Navigator?Pietenpol-List href="http://forums.matronics.com/">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/contribution (http://www.matronics.com/Navigator?Pietenpol-List) (http://www.matronics.com/contribution) ________________________________ Message 25 ____________________________________ Time: 07:53:25 AM PST US From: "Douwe Blumberg" Subject: Pietenpol-List: 4130 tubing I'm pretty sure that my last tubing from Aircraft Spruce said "Germany" on it. Douwe ________________________________ Message 26 ____________________________________ Time: 07:53:59 AM PST US From: Doug Dever Subject: RE: Pietenpol-List: Re: Wing Strut Fork End I Have to agree w/everyone here. There has to ba a reason those lift forks are a lot more expensive that turnbarrel forks. My guess is they are a lo t stronger in more ways than one. Doug Dever In beautiful Stow Ohio Subject: Re: Pietenpol-List: Re: Wing Strut Fork End From: rmueller23@gmail.com It has been explained to you why you should use purpose built wing struts f orks. Use the right tool for the right job. And you use the right tool for the right job because you want to go out and safely fly and enjoy your airp lane without having to be concerned about ending up as a smoking hole in th e ground=2C leaving your wife a widower and your children fatherless.....or god forbid hurt anyone else. Any obsession with making your Piet the "snow flakiest" of them all should not trump safety. Just do it right.....so we can drop this discussion already. :) Ryan On Mon=2C Jan 10=2C 2011 at 7:29 PM=2C Michael Perez wrote: et> I'm not trying to give anyone a hard time here=2C just trying to understand the logic. Michael Perez Karetaker Aero www.karetakeraero.com st" target="_blank">http://www.matronics.com/Navigator?Pietenpol-List http://forums.matronics.com le=2C List Admin. ="_blank">http://www.matronics.com/contribution ________________________________ Message 27 ____________________________________ Time: 07:56:10 AM PST US From: Michael Perez Subject: Re: Pietenpol-List: Re: Wing Strut Fork End Thank you sir.- The compression factor is a very good point. I do not ful ly understand how a steel fitting can be good in tension and not in compres sion, but I accept it. I understand rolled -V- cut on the threads. Fully aw are of the differences between steel and aluminum tensile strength. My original thought was the fact that these fittings were rated as high as 8000#. It does not matter if they are plastic, paper, cut or rolled threads , tiny or huge, they are rated as designed to handle 8000#. (tension) No id ea how they handle compression and I don't understand how tension and compr ession differ from a fittings point of view. (metallurgy I imagine) I plan to use my aluminum struts with- threaded aluminum inserts. (7050 o r 7075 aluminum.)- Since I will have a steel fitting threaded into said a luminum, I am curious if I need to be concerned with dis-similar metal corr osion and IF so, how to prevent it? These inserts will be threaded deep enough to accept the entire length of t he fork and the struts themselves cut to a length to keep as much of the fo rk threaded as possible. I thank you for your educated explanation. Michael Perez =0AKaretaker Aero =0Awww.karetakeraero.com --- On Tue, 1/11/11, hvandervoo@aol.com wrote: From: hvandervoo@aol.com Subject: Re: Pietenpol-List: Re: Wing Strut Fork End =0A=0A=0A=0A=0AThere are 3 factors that decide selection of the Fork-end of the main strut:=0A=0A=0A-=0A=0A=0A1) tension load, easily understood and both J-3 fork end and a Turnbuckle style fork can handle the required load .=0A=0A=0A-=0A=0A=0A2) compression load, often over looked but flying-i n turbulence often experienced, J-3 fork can handle this, Turnbuckle style can not.=0A=0A=0ARemember that turnbuckles are designed-for cable use, no compression loads there.=0A=0A=0A-=0A=0A=0A3) overlooked even more often is thread strength, diameter & length.=0A=0A=0AFor a steel fork end to wor k as designed the diameter should be same a as the-height of the nut inse rt-(nut part to be of the same material) =0A=0A=0A=0AIn other words a 5/16 Fork tread needs to have 5/16 nut height, if you tap in to the strut your tread dept needs to be at least 5/16.=0A =0A=0ANote: nut/ strut threads-of the same steel material,- more length is always better, rolled threads are better than cut/ tapped threads.=0A =0A=0A-=0A=0A=0AI use the J-3 style fork end with steel struts and the we ld-in treaded purpose build nut insert.=0A=0A=0A-=0A=0A=0ANow if you choo se to use aluminum struts and tap your own treads be aware that aluminum ha s a lower tensile strength than steel.=0A=0A=0ASo compensate by tapping a d eep/ long thread in to the best aluminum you can get.=0A=0A=0AYour fork tre ad might not be long enough.=0A=0A=0AYou might need to consider a steel ins ert.=0A=0A=0A-=0A=0A=0ATurnbuckles assemblies-with brass center piece u se the same principle, the tread depth is much longer ( 6-8 X ) than the di ameter of the tread.=0A=0A=0A-=0A=0A=0AI did not sleep in a Holiday-inn e xpress last night, but am a mechanical engineer by profession=0A=0A=0A- =0A=0A=0AHans=0A=0A=0A-=0A=0A=0ANX15KV=0A=0A=0A-=0A=0A=0A=0A ________________________________ Message 28 ____________________________________ Time: 08:04:38 AM PST US From: "TOM STINEMETZE" Subject: Pietenpol-List: Re: LG at last That cussing thing - very helpful and quite satisfying. Tom do not archive >>> "Don Emch" 1/11/2011 9:45 AM >>> Looks great Tom... maybe a tad taller than mine. What a great feeling for you! I've come very close to pulling my bungees and replacing with springs. But, I think I finally found a way to get the bungees tight enough with a come-along... and lots of cussing. Don Emch NX899DE ________________________________ Message 29 ____________________________________ Time: 08:27:37 AM PST US From: Kip and Beth Gardner Subject: Re: Pietenpol-List: Re: LG at last Yeah, my wife says that the tool I use most often is a "dammit". On Jan 11, 2011, at 11:00 AM, TOM STINEMETZE wrote: > That cussing thing - very helpful and quite satisfying. > > Tom > do not archive > > > >>> "Don Emch" 1/11/2011 9:45 AM >>> > Looks great Tom... maybe a tad taller than mine. What a great feeling for you! I've come very close to pulling my bungees and replacing with springs. But, I think I finally found a way to get the bungees tight enough with a come-along... and lots of cussing. > > Don Emch > NX899DE > > > ________________________________ Message 30 ____________________________________ Time: 08:28:37 AM PST US From: EDWARD BARCHIK Subject: RE: Pietenpol-List: Re: Tail wheel Thanks Adrian, kids love the project. ________________________________________ From: owner-pietenpol-list-server@matronics.com [owner-pietenpol-list-server@matronics.com] on behalf of pineymb [airltd@mts.net] Sent: Tuesday, January 11, 2011 8:03 AM Subject: Pietenpol-List: Re: Tail wheel The setup I used was a Matco tailwheel AS&S PN# 06-01615 and single leaf spring PN# 06-14500. Untested but I think will work fine and relatively inexpensive. -------- Adrian M Winnipeg, MB Canada Read this topic online here: http://forums.matronics.com/viewtopic.php?p=326471#326471 Attachments: http://forums.matronics.com//files/dscn0057_988.jpg http://forums.matronics.com//files/dsc00081_959.jpg Email secured by Check Point ________________________________ This message (including any attachments) is intended only for the use of the individual or entity to which it is addressed and may contain information that is non-public, proprietary, privileged, confidential, and exempt from disclosure under applicable law or may constitute as attorney work product. If you are not the intended recipient, you are hereby notified that any use, dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, notify us immediately by telephone and (i) destroy this message if a facsimile or (ii) delete this message immediately if this is an electronic communication. Thank you. Berwick Area School District ________________________________ Message 31 ____________________________________ Time: 08:49:55 AM PST US From: Lawrence Williams Subject: Pietenpol-List: wing strut fork ends You guys are really killing me here. I'm about ready to push my Piet out of the hangar and burn it. I used Gorilla glue, brazed fittings, coated wood pieces that contact the covering with spar varnish, didn't calculate where my wheels are located based on anything more scientific than where the oldtimers said they should be and now I find out that my struts have never been through the spanwise distribution load calculations!!!! Will it never end?? Thank goodness I didn't use a Corvair engine. How can I feel safe now that all these questions are unanswered? I never had the internet to tell me where holes should be drilled or what size cable to use or which side of a bulkhead a brace should be glued to. The only guidelines I ever had was looking at other (unsafe??) examples at Brodhead each summer and talking to their builders. How could I have been so gullible as to think that they were trained and seasoned engineers. I was so naiveto have followed their advice and now I am paying the price with nightmares and self-doubt. Should I douse the airframe with 100LL or diesel fuel?? Maybe auto gas....or wood alcohol? I do have kerosene and some Coleman fuel, too. Help, I can't make a decision like this without input. Then there are the environmental issues to consider prior to the bonfire. What will the down-wind damage be to the Ivory Billed Woodpecker habitat when my Polyfiber (gasp!) system carbonizes? Should I remove the tires before I light the thing off? It's all just too horrible to consider. Thankful to still be alive- Larry ps. I'm a quivering basket case but my Air Camper is performing like none of this matters. Is there a message there? ________________________________ Message 32 ____________________________________ Time: 09:05:51 AM PST US Subject: Re: Pietenpol-List: wing strut fork ends From: Ryan Mueller Larry, Do you mean to say that you just followed the plans, or copied what other builders had successfully done? How can you live with such a derivative aircraft? Ugh.... Ryan do not archive On Tue, Jan 11, 2011 at 10:47 AM, Lawrence Williams wrote: > You guys are really killing me here. I'm about ready to push my Piet out of > the hangar and burn it. > > I used Gorilla glue, brazed fittings, coated wood pieces that contact the > covering with spar varnish, didn't calculate where my wheels are located > based on anything more scientific than where the oldtimers said they should > be and now I find out that my struts have never been through the spanwise > distribution load calculations!!!! Will it never end?? Thank goodness I > didn't use a Corvair engine. > > How can I feel safe now that all these questions are unanswered? I never > had the internet to tell me where holes should be drilled or what size cable > to use or which side of a bulkhead a brace should be glued to. The only > guidelines I ever had was looking at other (unsafe??) examples at Brodhead > each summer and talking to their builders. How could I have been so gullible > as to think that they were trained and seasoned engineers. I was so naive to > have followed their advice and now I am paying the price with nightmares and > self-doubt. > > Should I douse the airframe with 100LL or diesel fuel?? Maybe auto > gas....or wood alcohol? I do have kerosene and some Coleman fuel, too. Help, > I can't make a decision like this without input. > > Then there are the environmental issues to consider prior to the bonfire. > What will the down-wind damage be to the Ivory Billed Woodpecker habitat > when my Polyfiber (gasp!) system carbonizes? Should I remove the tires > before I light the thing off? It's all just too horrible to consider. > > Thankful to still be alive- > > Larry > > ps. I'm a quivering basket case but my Air Camper is performing like none > of this matters. Is there a message there? > > * > > * > > ________________________________ Message 33 ____________________________________ Time: 09:07:00 AM PST US From: Michael Perez Subject: Re: Pietenpol-List: Re: Wing Strut Fork End If I may, could it be as simple as welding a threaded boss onto or between a couple steel plates. These plates then bolt to the strut and the strut fo rk threads into the boss? Some type of transition piece to get you from woo d to steel for the fork. Michael Perez =0AKaretaker Aero =0Awww.karetakeraero.com --- On Tue, 1/11/11, AMsafetyC@aol.com wrote: From: AMsafetyC@aol.com Subject: Re: Pietenpol-List: Re: Wing Strut Fork End =0A=0A =0A=0AWhen you find that out I would like to know all the details an d pics, I =0Aalready have my wooden struts and have been trying to come up with an attachment =0Amethod or design that's going to be safe and work wel l. So please share your =0Aresults.=0A-=0AThanks=0A-=0AJohn-=0A-=0A =0AIn a message dated 1/11/2011 9:59:49 A.M. Eastern Standard Time, =0Akipa ndbeth@earthlink.net writes:=0AWhile =0A we're on this topic, does anyone know of a way to make wooden lift struts =0A adjustable? I'm going to make mine from some # of -laminations, with at =0A least one layer of carbon fiber strands within the full strut, and probably =0A cross-wise layering s for extra reinforcement at the ends (still figuring out =0A the details, but similar to what Jim Markle did on his cabana struts). =0A -From the images I've found on various people's sites so far, it looks =0A like the only option for adjustment would be to remake the terminal fittings, =0A and I imagine there's a practical length limit with regard to twisting load s =0A (?) on those. -If adjustment is difficult or impossible (short of making =0A new struts), I'd think I'd want to put this off until just abou t everything =0A else is completed and I'm working on the initial rigging of the completed =0A wings? =0A =0A Any comments? -Thanks!=0A =0A Kip Gardner=0A =0A =0A =0A =0A On Jan 11, 2011, at 9:14 AM, Ryan Mueller wrote: =0A Give Wag-Aero a call, they manufacture them: =0A =0A http://www.wagaero.com/contact.html =0A On Tue, Jan 11, 2011 at 8:01 AM, Michael Perez =0A wrote: =0A =0A =0A =0A =0A =0A =0A =0A =0A =0A I =0A see the points of a few on this list and laugh at some of the =0A others, but I appreciate those who take the time to explain =0A their points of view and take the time to listen to mi ne. I =0A may ask around here at work and what people thin k. If I find =0A any good intell. along the way, I'll post it. By the =0A way, anyone know what the Piper forks are rated at? What =0A material? I could not find anything on them. - =0A Michael Perez Karetaker =0A Aero www.karetakeraero.com =0A =0A =0A " target="_blank">http://www.matronics.com/Navigator?Pietenpol-List tp://forums.matronics.com _blank">http://www.matronics.com/contribution href="http://www.matronics.com/Navigator?Pietenpol-List">http://www.matro nics.com/Navigator?Pietenpol-List href="http://forums.matronics.com/">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/con tribution t href="http://www.matronics.com/Navigator?Pietenpol-List">http://www.mat ronics.com/Navigator?Pietenpol-List ms.matronics.com/">http://forums.matronics.com tp://www.matronics.com/contribution">http://www.matronics.com/contribution =0A=0A ________________________________ Message 34 ____________________________________ Time: 09:24:57 AM PST US From: Kip and Beth Gardner Subject: Re: Pietenpol-List: Re: Wing Strut Fork End That would probably do it. It would have to be designed so the threaded end of the fork would not need a 'relief' hole drilled into the end of the strut to accommodate adjustments, or you create a pocket for rot to develop in, no matter how well you seal it. Also, the end grain of the strut would need to be exposed for inspection purposes, for the same reason. On Jan 11, 2011, at 12:04 PM, Michael Perez wrote: > If I may, could it be as simple as welding a threaded boss onto or > between a couple steel plates. These plates then bolt to the strut > and the strut fork threads into the boss? Some type of transition > piece to get you from wood to steel for the fork. > > Michael Perez > Karetaker Aero > www.karetakeraero.com > > --- On Tue, 1/11/11, AMsafetyC@aol.com wrote: > > From: AMsafetyC@aol.com > Subject: Re: Pietenpol-List: Re: Wing Strut Fork End > To: pietenpol-list@matronics.com > Date: Tuesday, January 11, 2011, 10:49 AM > > When you find that out I would like to know all the details and > pics, I already have my wooden struts and have been trying to come > up with an attachment method or design that's going to be safe and > work well. So please share your results. > > Thanks > > John > > In a message dated 1/11/2011 9:59:49 A.M. Eastern Standard Time, kipandbeth@earthlink.net > writes: > While we're on this topic, does anyone know of a way to make wooden > lift struts adjustable? I'm going to make mine from some # of > laminations, with at least one layer of carbon fiber strands within > the full strut, and probably cross-wise layerings for extra > reinforcement at the ends (still figuring out the details, but > similar to what Jim Markle did on his cabana struts). >From the > images I've found on various people's sites so far, it looks like > the only option for adjustment would be to remake the terminal > fittings, and I imagine there's a practical length limit with regard > to twisting loads (?) on those. If adjustment is difficult or > impossible (short of making new struts), I'd think I'd want to put > this off until just about everything else is completed and I'm > working on the initial rigging of the completed wings? > > Any comments? Thanks! > > Kip Gardner > > > On Jan 11, 2011, at 9:14 AM, Ryan Mueller wrote: > >> Give Wag-Aero a call, they manufacture them: >> >> http://www.wagaero.com/contact.html >> >> On Tue, Jan 11, 2011 at 8:01 AM, Michael Perez > > wrote: >> I see the points of a few on this list and laugh at some of the >> others, but I appreciate those who take the time to explain their >> points of view and take the time to listen to mine. I may ask >> around here at work and what people think. If I find any good >> intell. along the way, I'll post it. >> >> By the way, anyone know what the Piper forks are rated at? What >> material? I could not find anything on them. >> >> Michael Perez >> Karetaker Aero >> www.karetakeraero.com >> >> >> >> >> " target="_blank">http://www.matronics.com/Navigator?Pietenpol-List >> tp://forums.matronics.com >> _blank">http://www.matronics.com/contribution >> >> >> >> >> href="http://www.matronics.com/Navigator?Pietenpol-List">http://www.matronics.com/Navigator?Pietenpol-List >> href="http://forums.matronics.com/">http://forums.matronics.com >> href="http://www.matronics.com/contribution">http://www.matronics.com/contribution >> > > > =================================== > t > href="http://www.matronics.com/Navigator?Pietenpol-List">http://www.matronics.com/Navigator?Pietenpol-List > ========== > ms.matronics.com/">http://forums.matronics.com > ========== > tp://www.matronics.com/contribution">http://www.matronics.com/contribution > =================================== > > http://www.matronics.com/Navigw" target="_blank" href="http://forums.matronics.com > ">http://forums.mat > ========= > > ________________________________ Message 35 ____________________________________ Time: 09:25:52 AM PST US From: "Ray Krause" Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) As a non-engineer builder, if the lift struts require a rod end that will withstand 8000 lbs, or even 4000, I have a hard time imagining that those little attach plates made out of 12 g steel and held to the fuselage longerons by 3 or 4 3/16th in bolts would withstand that weight. My common sense make me nervous, but it seems to work? Just a comment. Thanks and fly SAFELY, Ray Krause Waiex 51YX, Jabiru 3300 (1197), Sensenich wood prop, AeroCarb (#2 needle modified), Dynon D-180, Garmin SL 30 NavCom, Garmin 327 transponder, Garmin Aera 560, nav and strobe lights: 236 hrs., building a Sky Scout.... slowly. ----- Original Message ----- From: Clif Dawson To: pietenpol-list@matronics.com Sent: Tuesday, January 11, 2011 1:34 AM Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) Attached is the lift distribution chart for hershey bar wings in the aspect ratio range of the Piet wing. From this you can deduce that there is only a small portion of the lift supported by the cabanes. Therefore, the majority of lift is handled by the struts. It's all in the archives, back there somewhere. :-) Also, my understanding is that one designs and builds to a safety factor of 1.5. So if an AC is placarded at 4G then it will go to 6 before failure. Clif It has to do with the distribution of lift. More lift is generated from the inboard section of the wing than the outboard sections. As a result there is less torque upward on the outer wing panels than if the lift was equal all of the way across the wing. This means that there is less force imposed on the lift strut. Malcolm Morrison http://home.comcast.net/~mmorrison123/ What in your math is different then Jack's 3200? Your numbers are quite different? Michael Perez ________________________________ Message 36 ____________________________________ Time: 09:46:23 AM PST US From: "Charles Campbell" Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) I have drilled so many 3/16" holes I have 3/16" on the brain. I, of course, meant 3/32" cables. ----- Original Message ----- From: "Jim Markle" Sent: Monday, January 10, 2011 5:37 PM Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) > > > ALWAYS use what the plans call out.... :-) > > I probably used 3/16.... > > jm > > > -----Original Message----- >>From: Charles Campbell >>Sent: Jan 10, 2011 2:37 PM >>To: pietenpol-list@matronics.com >>Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) >> >> >> >>My plans call for 3/16" diagonal/xbracing wires. >> >>----- Original Message ----- >>From: "Jim Markle" >>To: >>Sent: Monday, January 10, 2011 3:01 PM >>Subject: RE: Pietenpol-List: Please Check My Math (alum.wing strut) >> >> >>> >>> >>> So Jack (or anyone for that matter), >>> >>> How much (if any) of that load would you expect to be carried by those >>> 1/8" diagonal/Xbracing wires between the lift struts? >>> >>> Any of it? >>> >>> JM >>> >>> >>> -----Original Message----- >>> >>> From: Jack Phillips >>> >>> Sent: Jan 10, 2011 12:09 PM >>> >>> To: pietenpol-list@matronics.com >>> >>> Subject: RE: Pietenpol-List: Please Check My Math (alum.wing strut) >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> Michael, how are you arriving at 1200 lbs >>> per strut at 4 Gs? >>> >>> >>> >>> I could see that if your struts were >>> vertical (in line with the lift load). They are not, and since they are >>> at an >>> angle from the horizontal, each strut will see a load equal to the lift >>> load at >>> that point divided by the sine of the angle. For most Pietenpols, the >>> angle is >>> about 30 and the sine of 30 is .50, so if all four struts are carrying >>> a >>> quarter of the total load (theyre not the front struts tend to >>> carry more than the rears, due to the position of the center of >>> pressure, >>> and >>> the pressure distribution curve), and the total load is 4800 lbs, each >>> strut is >>> carrying 1200/.5 or 2400 lbs. >>> >>> >>> >>> Without knowing the pressure distribution >>> on the wing, I would assume for safetys sake that the front struts are >>> carrying 2/3 of the load and the rear struts only 1/3. If that is the >>> case, >>> then the load at each front strut fitting on the wing at 4 gs with a >>> 1200 lb gross weight would be 2/3 (2400) or 1600 lbs. This is assuming >>> that >>> each wing panel is generating half the lift or 2400 lbs, and the >>> centersection >>> is adding nothing, so again this is a conservative assumption. If the >>> lift >>> load at the front strut is 1600 lbs, the load in the strut itself will >>> be >>> twice >>> that (if the angle is 30) or 3200 lbs. Quite a bit different than the >>> 1200 >>> lbs you were calculating. >>> >>> >>> >>> Jack Phillips >>> >>> NX899JP Icarus Plummet >>> >>> Raleigh, NC >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> From: >>> owner-pietenpol-list-server@matronics.com >>> [mailto:owner-pietenpol-list-server@matronics.com] >>> On Behalf Of Michael Perez >>> >>> Sent: Monday, January 10, 2011 >>> 11:43 AM >>> >>> To: pietenpol-list@matronics.com >>> >>> Subject: Pietenpol-List: Please >>> Check My Math (alum.wing strut) >>> >>> >>> >>> >>> >>> >>> >>> >>> I am trying to figure out bolt hole edge spacing for >>> my aluminum wing struts. These struts are the small struts from Carlson >>> Aircraft. Doing the math, from the info. at the site, I get a wall >>> thickness of the strut at .119". Since the bolt would have to pull >>> through both walls, that number is now .238". >>> >>> >>> >>> I am going to assume that my plane's weight will be 1000# and my weight >>> will >>> be 200#. (I am 165# actually) for total weight of 1200#. >>> >>> >>> >>> The plans show using a 5/16" bolt. (.3125") 2X bolt diameter >>> minus 1/2 of a bolt diameter yields a hole edge spacing of .625 - >>> .15625 = .46875" >>> >>> >>> >>> .46875 X .238 (strut wall thickness) = .1115625 square inches. >>> >>> >>> >>> .1115625 X 11637 (SHEAR listed on the website for the small strut) = >>> 1298 >>> lbs. >>> >>> >>> >>> My 1200# plane at 4Gs is 4800#. Each lift strut will see about 1200 lbs >>> each. >>> (?) >>> >>> >>> >>> My aluminum struts with the 2 diameter bolt edge spacing should be able >>> to >>> handle 1298 lbs each...which is good for a 1200# plane at 4Gs. >>> >>> >>> >>> If I use an edge spacing of 1/2" even, then the new number is 1384# per >>> strut. >>> >>> >>> >>> Thanks for any help advice. >>> >>> >>> >>> Michael Perez >>> >>> Karetaker Aero >>> >>> www.karetakeraero.com >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >> >> >> >> >> > > > ________________________________ Message 37 ____________________________________ Time: 09:56:02 AM PST US From: KM Heide CPO/FAAOP Subject: Re: Pietenpol-List: wing strut fork ends Larry, Larry, Larry... You made my day and year with your post! Never laughed so hard in a long time. I agree with everything you say!!! KMHeide Fargo, ND --- On Tue, 1/11/11, Lawrence Williams wrote: > From: Lawrence Williams > Subject: Pietenpol-List: wing strut fork ends > To: "Pietlist" > Date: Tuesday, January 11, 2011, 10:47 AM > You > guys are really killing me here. I'm about ready to push > my Piet out of the hangar and burn it. > > I used Gorilla glue, brazed fittings, coated wood pieces > that contact the covering with spar varnish, didn't > calculate where my wheels are located based on anything more > scientific than where the oldtimers said they should be and > now I find out that my struts have never been through the > spanwise distribution load calculations!!!! Will it never > end?? Thank goodness I didn't use a Corvair engine. > > How can I feel safe now that all these questions are > unanswered? I never had the internet to tell me where holes > should be drilled or what size cable to use or which side of > a bulkhead a brace should be glued to. The only guidelines I > ever had was looking at other (unsafe??) examples at > Brodhead each summer and talking to their builders. How > could I have been so gullible as to think that they were > trained and seasoned engineers. I was so naive to have > followed their advice and now I am paying the price with > nightmares and self-doubt. > > Should I douse the airframe with 100LL or diesel fuel?? > Maybe auto gas....or wood alcohol? I do have kerosene and > some Coleman fuel, too. Help, I can't make a decision > like this without input. > > Then there are the environmental issues to consider prior > to the bonfire. What will the down-wind damage be to the > Ivory Billed Woodpecker habitat when my Polyfiber (gasp!) > system carbonizes? Should I remove the tires before I light > the thing off? It's all just too horrible to consider. > > Thankful to still be alive- > > Larry > > ps. I'm a quivering basket case but my Air Camper is > performing like none of this matters. Is there a message > there? > > > > > > > > ________________________________ Message 38 ____________________________________ Time: 10:05:00 AM PST US Subject: Re: Pietenpol-List: Re: Corvair Challenges and 5th Bearing From: Rick Holland Yes Kevin, Mark from Falcon is one of the guys that hangs with WW at AirVenture. Does great work including heavier steel valve seat inserts that he designed. rick On Mon, Jan 10, 2011 at 9:16 PM, kevinpurtee wrote: > kevin.purtee@us.army.mil> > > It's all good! > > Rick - I got the heads done by a shop in Houston. He was recommended by > the local CORSA tech counselor. Don't think Falcon was even part of the > vocabulary way back then. Are they the shop of choice, now? > > Kevin > > -------- > Kevin "Axel" Purtee > NX899KP > Austin/Georgetown, TX > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=326440#326440 > > -- Rick Holland Castle Rock, Colorado "Logic is a wreath of pretty flowers, that smell bad" ________________________________ Message 39 ____________________________________ Time: 10:09:22 AM PST US Subject: Re: Pietenpol-List: steel From: Rick Holland Wow, 4 DH-2s, neat aircraft, what engines are you planning on using? rick On Mon, Jan 10, 2011 at 10:07 PM, Ernie Moreno wrote: > Had a conversation with my steel tube supplier today. For the record, my > supplier is Tube Service in Portland Or. They advised me that there is 4130 > Chromoly Steel available US made. It is available through a company called > Wesco (is somewhere in Southern Calif.) and from Plymouth (in Arizona). From > past experience I know that Plymouth does aluminium tubing also. My > supplier agreed to replace all the Chinese tubing with made in USA tubing > for no change in price. A great company. For the record I and four other > individuals are building full size DH-2's. Using the basic Pietenpol specs > on the gear, Ken Perkins hubs, 21"wheels with 21x3.25 tires. > > Ernie Moreno > Piet 2431 > > * > > * > > -- Rick Holland Castle Rock, Colorado "Logic is a wreath of pretty flowers, that smell bad" ________________________________ Message 40 ____________________________________ Time: 10:11:11 AM PST US From: "Charles Campbell" Subject: Re: Pietenpol-List: Re: Corvair Challenges and 5th Bearing Falcon is the only Head man that WW recomends. ----- Original Message ----- From: "kevinpurtee" Sent: Monday, January 10, 2011 11:16 PM Subject: Pietenpol-List: Re: Corvair Challenges and 5th Bearing > > > It's all good! > > Rick - I got the heads done by a shop in Houston. He was recommended by > the local CORSA tech counselor. Don't think Falcon was even part of the > vocabulary way back then. Are they the shop of choice, now? > > Kevin > > -------- > Kevin "Axel" Purtee > NX899KP > Austin/Georgetown, TX > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=326440#326440 > > > ________________________________ Message 41 ____________________________________ Time: 10:23:54 AM PST US From: airlion Subject: Re: Pietenpol-List: wing strut fork ends ----- Original Message ---- From: KM Heide CPO/FAAOP Sent: Tue, January 11, 2011 12:53:06 PM Subject: Re: Pietenpol-List: wing strut fork ends Larry, Larry, Larry... You made my day and year with your post! Never laughed so hard in a long time. I agree with everything you say!!! KMHeide Fargo, ND --- On Tue, 1/11/11, Lawrence Williams wrote: > From: Lawrence Williams > Subject: Pietenpol-List: wing strut fork ends > To: "Pietlist" > Date: Tuesday, January 11, 2011, 10:47 AM > You > guys are really killing me here. I'm about ready to push > my Piet out of the hangar and burn it. > > I used Gorilla glue, brazed fittings, coated wood pieces > that contact the covering with spar varnish, didn't > calculate where my wheels are located based on anything more > scientific than where the oldtimers said they should be and > now I find out that my struts have never been through the > spanwise distribution load calculations!!!! Will it never > end?? Thank goodness I didn't use a Corvair engine. > > How can I feel safe now that all these questions are > unanswered? I never had the internet to tell me where holes > should be drilled or what size cable to use or which side of > a bulkhead a brace should be glued to. The only guidelines I > ever had was looking at other (unsafe??) examples at > Brodhead each summer and talking to their builders. How > could I have been so gullible as to think that they were > trained and seasoned engineers. I was so naive to have > followed their advice and now I am paying the price with > nightmares and self-doubt. > > Should I douse the airframe with 100LL or diesel fuel?? > Maybe auto gas....or wood alcohol? I do have kerosene and > some Coleman fuel, too. Help, I can't make a decision > like this without input. > > Then there are the environmental issues to consider prior > to the bonfire. What will the down-wind damage be to the > Ivory Billed Woodpecker habitat when my Polyfiber (gasp!) > system carbonizes? Should I remove the tires before I light > the thing off? It's all just too horrible to consider. > > Thankful to still be alive- > > Larry > > ps. I'm a quivering basket case but my Air Camper is > performing like none of this matters. Is there a message > there? > > > > > > > > ________________________________ Message 42 ____________________________________ Time: 10:23:56 AM PST US From: "Charles Campbell" Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) EF Bruhn's book "Analysis and Design of Aircraft Structures" would disagree with your statement that more lift is generated from the inboard section than the outboard sections. That would be true if the wing is tapered, but I'm looking at a diagram of a rectangular wing with spars of equal depth the entire length and the diagram of airload shows the same load on the tip as on the root. ----- Original Message ----- From: gliderx5@comcast.net To: pietenpol-list@matronics.com Sent: Monday, January 10, 2011 11:19 PM Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) It has to do with the distribution of lift. More lift is generated from the inboard section of the wing than the outboard sections. As a result there is less torque upward on the outer wing panels than if the lift was equal all of the way across the wing. This means that there is less force imposed on the lift strut. Let me caution you a little in that I am a software engineer with great interest in aviation, NOT a mechanical or aerospace engineer, so I could be full of crap! But, I have friends that are aeronautical engineers and I have run this by them. Someone could argue the numbers, but it should be very close. Malcolm Morrison http://home.comcast.net/~mmorrison123/ ----- Original Message ----- From: "Michael Perez" To: pietenpol-list@matronics.com Sent: Monday, January 10, 2011 9:38:03 PM Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) What in your math is different then Jack's 3200? Your numbers are quite different? Michael Perez Karetaker Aero www.karetakeraero.com --- On Mon, 1/10/11, gliderx5@comcast.net wrote: > From: gliderx5@comcast.net > Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) > To: pietenpol-list@matronics.com > Date: Monday, January 10, 2011, 8:43 PM > #yiv909872567 p > {margin:0;}I > actually tried to determine these numbers a while back and > put them on my web site at > http://home.comcast.net/~mmorrison123/wing_loads.html > . It's probably a goofy thing to read, but I tried > to include the effect of an elliptical lift distribution, > which is what you have with a rectangular wing. > Adjusting my numbers up for a 1200 lb airplane at 4 Gs I get > about 1760 lbs on the strut ends. Should be a little > more on the front, and a little less on the rear. > > Malcolm Morrison > http://home.comcast.net/~mmorrison123.html > > ----- Original Message ----- > From: "Jack Phillips" > > To: pietenpol-list@matronics.com > Sent: Monday, January 10, 2011 1:09:25 PM > Subject: RE: Pietenpol-List: Please Check My Math > (alum.wing strut) > > > > > > > > > > > > > > > > > > > Michael, > how are you arriving at 1200 lbs > per strut at 4 G=99s? > > > > I could > see that if your struts were > vertical (in line with the lift load). They are not, > and since they are at an > angle from the horizontal, each strut will see a load equal > to the lift load at > that point divided by the sine of the angle. For most > Pietenpols, the angle is > about 30=C2=B0 and the sine of 30=C2=B0 is .50, so if all four > struts are carrying a > quarter of the total load (they=99re not =93 the front > struts tend to > carry more than the rears, due to the position of the > center of pressure, and > the pressure distribution curve), and the total load is > 4800 lbs, each strut is > carrying 1200/.5 or 2400 lbs. > > > > Without > knowing the pressure distribution > on the wing, I would assume for safety=99s sake that the > front struts are > carrying 2/3 of the load and the rear struts only > 1/3. If that is the case, > then the load at each front strut fitting on the wing at 4 > g=99s with a > 1200 lb gross weight would be 2/3 (2400) or 1600 lbs. > This is assuming that > each wing panel is generating half the lift or 2400 lbs, > and the centersection > is adding nothing, so again this is a conservative > assumption. If the lift > load at the front strut is 1600 lbs, the load in the strut > itself will be twice > that (if the angle is 30=C2=B0) or 3200 lbs. Quite a bit > different than the 1200 > lbs you were calculating. > > > > Jack > Phillips > > NX899JP > =9CIcarus Plummet=9D > > Raleigh, > NC > > > > > > > > > > > > From: > owner-pietenpol-list-server@matronics.com > [mailto:owner-pietenpol-list-server@matronics.com] > On Behalf Of Michael Perez > > Sent: Monday, > January 10, 2011 > 11:43 AM > > To: > pietenpol-list@matronics.com > > Subject: > Pietenpol-List: Please > Check My Math (alum.wing strut) > > > > > > > > > I am trying to > figure out bolt hole edge spacing for > my aluminum wing struts. These struts are the small > struts from Carlson > Aircraft. Doing the math, from the info. at the > site, I get a wall > thickness of the strut at .119". Since the > bolt would have to pull > through both walls, that number is now .238". > > > > I am going to assume that my plane's weight will be > 1000# and my weight will > be 200#. (I am 165# actually) for total weight of 1200#. > > > > The plans show using a 5/16" bolt. > (.3125") 2X bolt diameter > minus 1/2 of a bolt diameter yields a hole edge spacing > of .625 - > .15625 = .46875" > > > > .46875 X .238 (strut wall thickness) = .1115625 square > inches. > > > > .1115625 X 11637 (SHEAR listed on the website for the > small strut) = 1298 > lbs. > > > > My 1200# plane at 4Gs is 4800#. Each lift strut will see > about 1200 lbs each. > (?) > > > > My aluminum struts with the 2 diameter bolt edge spacing > should be able to > handle 1298 lbs each...which is good for a 1200# plane at > 4Gs. > > > > If I use an edge spacing of 1/2" even, then the new > number is 1384# per > strut. > > > > Thanks for any help advice. > > > > Michael Perez > > Karetaker Aero > > www.karetakeraero.com > > > > > > > > > > > > > > " > target="_blank">http://www.matronics.com/Navigator?Pietenpol-List > tp://forums.matronics.com > _blank">http://www.matronics.com/contribution > > &== ________________________________ Message 43 ____________________________________ Time: 10:26:59 AM PST US Subject: Re: Re: Pietenpol-List: LG at last From: Rick Holland I know, could possibly rent a automotive valve spring compressor. The 1/2" figure is just what I needed, obviously the amount depends on the stiffness of the springs you use and the weight that's on the mains. rick On Mon, Jan 10, 2011 at 8:28 PM, Jack wrote: > Rick, > > You mentioned pre-load=85do you mean compress the spring =BD inch when > assembled? For my springs that would be a bunch of pressure. > > Thanks, > > Jack > > DSM > > > ------------------------------ > > *From:* owner-pietenpol-list-server@matronics.com [mailto: > owner-pietenpol-list-server@matronics.com] *On Behalf Of *Rick Holland > *Sent:* Monday, January 10, 2011 8:08 PM > *To:* pietenpol-list@matronics.com > *Subject:* Re: Pietenpol-List: LG at last > > > I used the attached design for mine using die springs that can be ordered > online. Remember to pre-load the spring by half and inch or so. > > rick > > On Mon, Jan 10, 2011 at 6:07 PM, Ben Charvet wrote : > > I'm thinking of replacing my bungees with springs like you have. Did you > make the spring struts yourself, or buy them ready made? > > Ben Charvet > NX866BC > > > On 1/10/2011 5:09 PM, TOM STINEMETZE wrote: > > *Well it's kind of bittersweet since I already know that this set of > landing gear will have to be rebuilt before the plane gets to move much. > BUT it's still a grand feeling to have N328X up on its gear at last. The re > is just something about being able to swing a leg up and sit with your ba ck > firmly settled into the seat and everything pointing UP! Now I can start > installing a lot of those things that have been occupying shelf space and > looking for a home.* > > > *My wife had to call me in to supper several times before I could bring > myself to vacate that seat. A'course some of the was due to the fact tha t I > couldn't figure out what to grab to get me standing back up again.* > > > *Ken Perkins hubs and spring shocks; spokes from Buchanans; 19" aluminum > rims from a local cycle shop; weldable axles from AS&S; brake calipers fr om > surplus Honda Shadow; brake disks my design from a local machine shop; br ake > brackets from my son in CA. Truely a "melting pot" project. Oh, and my own > ugly welding on everything.* > > > *Tom Stinemetze* > > *N328X* > > > * * > > * * > > *" target="_blank">http://www.matronics.com/Navigator?Pietenpol-List* > > *tp://forums.matronics.com* > > *_blank">http://www.matronics.com/contribution* > > * * > > > -- > Rick Holland > Castle Rock, Colorado > > "Logic is a wreath of pretty flowers, that smell bad" > > * > =========== > =========== =========== =========== > > * > > -- Rick Holland Castle Rock, Colorado "Logic is a wreath of pretty flowers, that smell bad" ________________________________ Message 44 ____________________________________ Time: 10:28:21 AM PST US Subject: Pietenpol-List: Re: BPA article From: "K5YAC" I agree... I really liked this issue. Plan to reread it in a day or so because I know there is stuff that I missed... lots of info. -------- Mark Chouinard Wings, Center Section and Empannage framed up - Working on Fuselage Read this topic online here: http://forums.matronics.com/viewtopic.php?p=326538#326538 ________________________________ Message 45 ____________________________________ Time: 10:33:58 AM PST US From: "Charles Campbell" Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) Michael, I don't want to see even 4 Gs. ----- Original Message ----- From: Michael Perez To: pietenpol-list@matronics.com Sent: Tuesday, January 11, 2011 8:26 AM Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) Thanks Cliff. My understanding as with you, (and I BELIEVE the way things are designed here at work) is to use a safety factor of 1.5. That is why I questioned the factor of 3 posted earlier. Using my original post and Jack P's calculated 3200# with a safety factor of 1.5 that would be 4800#. Anyone know of a Pietenpol seeing 6 Gs? Michael Perez Karetaker Aero www.karetakeraero.com --- On Tue, 1/11/11, Clif Dawson wrote: From: Clif Dawson Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) To: pietenpol-list@matronics.com Date: Tuesday, January 11, 2011, 4:34 AM =EF=BB Attached is the lift distribution chart for hershey bar wings in the aspect ratio range of the Piet wing. From this you can deduce that there is only a small portion of the lift supported by the cabanes. Therefore, the majority of lift is handled by the struts. It's all in the archives, back there somewhere. :-) Also, my understanding is that one designs and builds to a safety factor of 1.5. So if an AC is placarded at 4G then it will go to 6 before failure. Clif It has to do with the distribution of lift. More lift is generated from the inboard section of the wing than the outboard sections. As a result there is less torque upward on the outer wing panels than if the lift was equal all of the way across the wing. This means that there is less force imposed on the lift strut. Malcolm Morrison http://home.comcast.net/~mmorrison123/ What in your math is different then Jack's 3200? Your numbers are quite different? Michael Perez ________________________________ Message 46 ____________________________________ Time: 10:36:21 AM PST US Subject: Re: Pietenpol-List: Hole Depth for Piper fork From: Rick Holland I would wait till I had the fork to make sure. My hole centers are 5/8" from the outer edge to fit the forks I bought from ACS. rick On Tue, Jan 11, 2011 at 8:35 AM, Michael Perez wrote: > Since I will be welding my steel straps onto my landing gear fittings, I > need to pre-drill the hole for the wing strut fork. How deep from the edge > of the fitting does the hole need to be so that the Piper fork will fit? I > assume the standard 2X bolt diameter will work, but I want to be sure prior > to drilling and welding. > > Michael Perez > Karetaker Aero > www.karetakeraero.com > > * > > * > > -- Rick Holland Castle Rock, Colorado "Logic is a wreath of pretty flowers, that smell bad" ________________________________ Message 47 ____________________________________ Time: 10:43:23 AM PST US Subject: Re: Pietenpol-List: Re: Tail wheel From: Rick Holland Wish you would have been my wood shop teacher back in the 60s. All I got out of my wood shop class was a lousy walnut knife rack. With all the metal cutting/grinding/welding work (and some sheet metal/rivet work) needed on a Piet I would think the project would overlap nicely with metal shop also. rick On Tue, Jan 11, 2011 at 5:34 AM, EDWARD BARCHIK wrote: > Rick, This is a woodshop class. The students are 3rd and 4th year > students, Juniors and Seniors. We hope to complete project in spring 2012. > Ed > ------------------------------ > *From:* owner-pietenpol-list-server@matronics.com [ > owner-pietenpol-list-server@matronics.com] on behalf of Rick Holland [ > at7000ft@gmail.com] > *Sent:* Monday, January 10, 2011 6:40 PM > > *To:* pietenpol-list@matronics.com > *Subject:* Re: Pietenpol-List: Re: Tail wheel > > That's the same one I have Charles. Used with a used J3 two piece leaf > spring I got off ebay. > > rick > > On Mon, Jan 10, 2011 at 3:31 PM, Charles Campbell < > cncampbell@windstream.net> wrote: > >> Rick, what model Matco tailwheel did you use? I am thinking about a >> Matco WHLT-6. The specs say it has an operating load of 450#. >> >> ----- Original Message ----- >> *From:* Rick Holland >> *To:* pietenpol-list@matronics.com >> *Sent:* Monday, January 10, 2011 4:09 PM >> *Subject:* Re: Pietenpol-List: Re: Tail wheel >> >> I used a Matco, much lighter and cheaper than a Scott: >> >> http://www.matcomfg.com/TailWheelAssemblies-tp2-13.html >> >> On Mon, Jan 10, 2011 at 11:49 AM, Earnest Bunbury > > wrote: >> >>> We've used both a Maule and a Scott, both 6-in., full-swivel, steerable, >>> with detent. The Scott came with the plane and was a bit squirrelly. The >>> Maule was a gift from one of the guys at the field. It works "better" but >>> both of them are heavy and way over-engineered for the purpose. If you're >>> going with a new set-up, I would buy the lightest that can handle the load >>> or build from scratch. There are some cool solutions out there, some of >>> which are shown at westcoastpiet, as Kevin mentioned. >>> >>> What sort of class are the kids in? Is this a shop class or an >>> aviation-oriented class? >>> >>> Good luck and keep us updated! >>> >>> >>> * >>> >>> " target="_blank">http://www.matronics.com/Navigator?Pietenpol-List >>> tp://forums.matronics.com >>> _blank">http://www.matronics.com/contribution >>> * >>> >>> >> >> >> -- >> Rick Holland >> Castle Rock, Colorado >> >> "Logic is a wreath of pretty flowers, that smell bad" >> >> * >> >> href="http://www.matronics.com/Navigator?Pietenpol-List">http://www.matronics.com/Navigator?Pietenpol-List >> href="http://forums.matronics.com">http://forums.matronics.com >> href="http://www.matronics.com/contribution">http://www.matronics.com/c* >> >> * >> >> " target="_blank">http://www.matronics.com/Navigator?Pietenpol-List >> tp://forums.matronics.com >> _blank">http://www.matronics.com/contribution >> * >> >> > > > -- > Rick Holland > Castle Rock, Colorado > > "Logic is a wreath of pretty flowers, that smell bad" > > * > > " target="_blank">http://www.matronics.com/Navigator?Pietenpol-List > tp://forums.matronics.com > _blank">http://www.matronics.com/contribution > * > > > Email secured by Check Point > > > ------------------------------ > > This message (including any attachments) is intended only for the use of > the individual or entity to which it is addressed and may contain > information that is non-public, proprietary, privileged, confidential, and > exempt from disclosure under applicable law or may constitute as attorney > work product. If you are not the intended recipient, you are hereby notified > that any use, dissemination, distribution, or copying of this communication > is strictly prohibited. If you have received this communication in error, > notify us immediately by telephone and (i) destroy this message if a > facsimile or (ii) delete this message immediately if this is an electronic > communication. > > Thank you. Berwick Area School District > > * > > * > > -- Rick Holland Castle Rock, Colorado "Logic is a wreath of pretty flowers, that smell bad" ________________________________ Message 48 ____________________________________ Time: 10:49:04 AM PST US Subject: Pietenpol-List: Re: wing strut fork ends From: "DOMIT" Just build it like the plans! (Since I'm doing my own plans I can do that, right?) :P -------- Brad "DOMIT" Smith First rule of ground school: This is the ground... don't hit it going fast. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=326545#326545 ________________________________ Message 49 ____________________________________ Time: 10:51:26 AM PST US From: "Charles Campbell" Subject: Re: Pietenpol-List: wing strut fork ends I like your style, Lawrence. ----- Original Message ----- From: Lawrence Williams To: Pietlist Sent: Tuesday, January 11, 2011 11:47 AM Subject: Pietenpol-List: wing strut fork ends You guys are really killing me here. I'm about ready to push my Piet out of the hangar and burn it. I used Gorilla glue, brazed fittings, coated wood pieces that contact the covering with spar varnish, didn't calculate where my wheels are located based on anything more scientific than where the oldtimers said they should be and now I find out that my struts have never been through the spanwise distribution load calculations!!!! Will it never end?? Thank goodness I didn't use a Corvair engine. How can I feel safe now that all these questions are unanswered? I never had the internet to tell me where holes should be drilled or what size cable to use or which side of a bulkhead a brace should be glued to. The only guidelines I ever had was looking at other (unsafe??) examples at Brodhead each summer and talking to their builders. How could I have been so gullible as to think that they were trained and seasoned engineers. I was so naive to have followed their advice and now I am paying the price with nightmares and self-doubt. Should I douse the airframe with 100LL or diesel fuel?? Maybe auto gas....or wood alcohol? I do have kerosene and some Coleman fuel, too. Help, I can't make a decision like this without input. Then there are the environmental issues to consider prior to the bonfire. What will the down-wind damage be to the Ivory Billed Woodpecker habitat when my Polyfiber (gasp!) system carbonizes? Should I remove the tires before I light the thing off? It's all just too horrible to consider. Thankful to still be alive- Larry ps. I'm a quivering basket case but my Air Camper is performing like none of this matters. Is there a message there? ________________________________ Message 50 ____________________________________ Time: 10:53:01 AM PST US Subject: Pietenpol-List: Re: RV10-List: Airfoil Drag Video... From: "DOMIT" [quote="Michael Perez"]GREAT! I need some air foil shaped cable, (at no extra $$ the standard cable) and some air foil shaped spokes...or maybe I should just trash my brand new wheels altogether... Michael Perez Karetaker Aero www.karetakeraero.com > [b] Not that I would suggest using such a thing... but they do make flat blade spokes for racing bicycles. :P -------- Brad "DOMIT" Smith First rule of ground school: This is the ground... don't hit it going fast. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=326546#326546 ________________________________ Message 51 ____________________________________ Time: 11:02:31 AM PST US Subject: Pietenpol-List: Wing Strut Fork End Concerns From: "BYD" I heard a story that Im hoping someone can verify that would help in the Wing Strut Fork End concerns. To convince those arguing about struts, brackets and fittings, Bernard removed the struts from one of his planes and flew it around the patch once to prove what he designed was sufficient. It was emphasized that this was done on a calm day and with a solid wing. Anyone one else ever hear this story? Read this topic online here: http://forums.matronics.com/viewtopic.php?p=326549#326549 ________________________________ Message 52 ____________________________________ Time: 11:09:53 AM PST US Subject: Pietenpol-List: Re: 4130 tubing From: "K5YAC" Hmm, well then something doesn't jive. Either AS&S isn't getting their tubing from Dillsburg, or Dillsburg isn't getting his tubing from China. I hope the latter is true, but it could also explain why he is the cheapest in the business. I'm about ready to build the kiddo a go-kart out of this crap and plunk down the money for the good stuff, which I thought I was getting. I'll look at my material to see if there are any markings that indicate origin. I'll compare it to the stuff that I get from AS&S as well. I can say this... in comparison to a few pieces of 4130 that we have at work, the tubing I got from Dillsburg looks like gas pipe. The material at work is from Jorgensen... the surfaces (especially inside) are very smooth and shiny. Not the case with the Dillsburg tubing. In all fairness, I haven't taken the time to cut and clean a piece up, but I think I might do that this evening and bring it in tomorrow. Aww, the heck with it, I'm calling Vogelsong... Yep, I spoke to his secretary and she confirmed it... Chinese tubing. She also told me that his son (mentioned in another thread) no longer works for him. I said, "Imagine that." She came right out and said it... he really doesn't care anymore. People have tried to talk to him, but he makes it clear to them that he is in charge and the place will be run the way he wants. I can somewhat understand that, but at some point it will be run into the ground. Jorgensen says no way on Chinese tube... 70%-80% of their 4130 tubing is domestic, but some comes from England, Germany or other European locations. I'll be checking with Trident, AS&S and others just out of curiosity. The Jorgensen rep did tell me to look closely at the line marking and that it should state not only what type and dimension, but what mill it was run at as well as what ATSM standard it meets. He also said that we could line up tubing from 5 different vendors and that all of them would look slightly different as far as finish, so that is no way to compare. The only way to know for sure is to take samples to Sherry Labs (local) and have them test it. I could probably reorder the entire batch from a reputible outfit for less. -------- Mark Chouinard Wings, Center Section and Empannage framed up - Working on Fuselage Read this topic online here: http://forums.matronics.com/viewtopic.php?p=326552#326552 ________________________________ Message 53 ____________________________________ Time: 11:41:09 AM PST US From: Michael Perez Subject: Re: Pietenpol-List: Hole Depth for Piper fork Copy Rick thanks. Michael Perez Karetaker Aero www.karetakeraero.com --- On Tue, 1/11/11, Rick Holland wrote: From: Rick Holland Subject: Re: Pietenpol-List: Hole Depth for Piper fork I would wait till I had the fork to make sure. My hole centers are 5/8" from the outer edge to fit the forks I bought from ACS. rick On Tue, Jan 11, 2011 at 8:35 AM, Michael Perez wrote: Since I will be welding my steel straps onto my landing gear fittings, I need to pre-drill the hole for the wing strut fork. How deep from the edge of the fitting does the hole need to be so that the Piper fork will fit? I assume the standard 2X bolt diameter will work, but I want to be sure prior to drilling and welding. Michael Perez Karetaker Aero www.karetakeraero.com " target="_blank">http://www.matronics.com/Navigator?Pietenpol-List tp://forums.matronics.com _blank">http://www.matronics.com/contribution -- Rick Holland Castle Rock, Colorado "Logic is a wreath of pretty flowers, that smell bad" ________________________________ Message 54 ____________________________________ Time: 11:41:14 AM PST US Subject: Re: Pietenpol-List: wing strut fork ends From: Rick Holland And don't forget to remove and cut sections out of your engine mount, gear, cabanes, struts, etc. and have the steel tested to make sure it's not made in China (may have a high lead content like those kid toys last year). Then roll your project out to the driveway and burn it, for your own good. (But do get an EPA and local fire department permit first). On Tue, Jan 11, 2011 at 9:47 AM, Lawrence Williams wrote: > You guys are really killing me here. I'm about ready to push my Piet out of > the hangar and burn it. > > I used Gorilla glue, brazed fittings, coated wood pieces that contact the > covering with spar varnish, didn't calculate where my wheels are located > based on anything more scientific than where the oldtimers said they should > be and now I find out that my struts have never been through the spanwise > distribution load calculations!!!! Will it never end?? Thank goodness I > didn't use a Corvair engine. > > How can I feel safe now that all these questions are unanswered? I never > had the internet to tell me where holes should be drilled or what size cable > to use or which side of a bulkhead a brace should be glued to. The only > guidelines I ever had was looking at other (unsafe??) examples at Brodhead > each summer and talking to their builders. How could I have been so gullible > as to think that they were trained and seasoned engineers. I was so naive to > have followed their advice and now I am paying the price with nightmares and > self-doubt. > > Should I douse the airframe with 100LL or diesel fuel?? Maybe auto > gas....or wood alcohol? I do have kerosene and some Coleman fuel, too. Help, > I can't make a decision like this without input. > > Then there are the environmental issues to consider prior to the bonfire. > What will the down-wind damage be to the Ivory Billed Woodpecker habitat > when my Polyfiber (gasp!) system carbonizes? Should I remove the tires > before I light the thing off? It's all just too horrible to consider. > > Thankful to still be alive- > > Larry > > ps. I'm a quivering basket case but my Air Camper is performing like none > of this matters. Is there a message there? > > * > > * > > -- Rick Holland Castle Rock, Colorado "Logic is a wreath of pretty flowers, that smell bad" ________________________________ Message 55 ____________________________________ Time: 11:41:19 AM PST US Subject: Re: Pietenpol-List: Wing Strut Fork End Concerns From: Ryan Mueller Strong wing or not, it's not a cantilever wing.....you must have wing struts. Ryan On Tue, Jan 11, 2011 at 1:00 PM, BYD wrote: > > I heard a story that I=92m hoping someone can verify that would help in t he > Wing Strut Fork End concerns. To convince those arguing about struts, > brackets and fittings, Bernard removed the struts from one of his planes and > flew it around the patch once to prove what he designed was sufficient. It > was emphasized that this was done on a calm day and with a solid wing. > > Anyone one else ever hear this story? > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=326549#326549 > > =========== =========== =========== =========== > > ________________________________ Message 56 ____________________________________ Time: 11:41:43 AM PST US Subject: Re: Pietenpol-List: Re: 4130 tubing From: Kenneth Bickers I received a shipment of 4130 steel last week from Aircraft Spruce. I didn't read the printing on every tube and piece of sheet, but "Germany" was printed on the ones that I did inspect. Cheers, Ken On Tue, Jan 11, 2011 at 12:07 PM, K5YAC wrote: > > Hmm, well then something doesn't jive. Either AS&S isn't getting their > tubing from Dillsburg, or Dillsburg isn't getting his tubing from China. I > hope the latter is true, but it could also explain why he is the cheapest in > the business. I'm about ready to build the kiddo a go-kart out of this crap > and plunk down the money for the good stuff, which I thought I was getting. > > I'll look at my material to see if there are any markings that indicate > origin. I'll compare it to the stuff that I get from AS&S as well. I can > say this... in comparison to a few pieces of 4130 that we have at work, the > tubing I got from Dillsburg looks like gas pipe. The material at work is > from Jorgensen... the surfaces (especially inside) are very smooth and > shiny. Not the case with the Dillsburg tubing. In all fairness, I haven't > taken the time to cut and clean a piece up, but I think I might do that this > evening and bring it in tomorrow. > > Aww, the heck with it, I'm calling Vogelsong... > > Yep, I spoke to his secretary and she confirmed it... Chinese tubing. She > also told me that his son (mentioned in another thread) no longer works for > him. I said, "Imagine that." She came right out and said it... he really > doesn't care anymore. People have tried to talk to him, but he makes it > clear to them that he is in charge and the place will be run the way he > wants. I can somewhat understand that, but at some point it will be run > into the ground. > > Jorgensen says no way on Chinese tube... 70%-80% of their 4130 tubing is > domestic, but some comes from England, Germany or other European locations. > I'll be checking with Trident, AS&S and others just out of curiosity. The > Jorgensen rep did tell me to look closely at the line marking and that it > should state not only what type and dimension, but what mill it was run at > as well as what ATSM standard it meets. He also said that we could line up > tubing from 5 different vendors and that all of them would look slightly > different as far as finish, so that is no way to compare. The only way to > know for sure is to take samples to Sherry Labs (local) and have them test > it. I could probably reorder the entire batch from a reputible outfit for > less. > > -------- > Mark Chouinard > Wings, Center Section and Empannage framed up - Working on Fuselage > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=326552#326552 > > ________________________________ Message 57 ____________________________________ Time: 12:07:34 PM PST US From: Doug Dever Subject: RE: Pietenpol-List: Re: Wing Strut Fork End You could always cadmium plate them that is what is done to bolts and seapl ane fittings. Doug Dever In beautiful Stow Ohio From: speedbrake@sbcglobal.net Subject: Re: Pietenpol-List: Re: Wing Strut Fork End Thank you sir. The compression factor is a very good point. I do not fully understand how a steel fitting can be good in tension and not in compressi on=2C but I accept it. I understand rolled -V- cut on the threads. Fully aw are of the differences between steel and aluminum tensile strength. My original thought was the fact that these fittings were rated as high as 8000#. It does not matter if they are plastic=2C paper=2C cut or rolled thr eads=2C tiny or huge=2C they are rated as designed to handle 8000#. (tensio n) No idea how they handle compression and I don't understand how tension a nd compression differ from a fittings point of view. (metallurgy I imagine) I plan to use my aluminum struts with threaded aluminum inserts. (7050 or 7075 aluminum.) Since I will have a steel fitting threaded into said alumi num=2C I am curious if I need to be concerned with dis-similar metal corros ion and IF so=2C how to prevent it? These inserts will be threaded deep enough to accept the entire length of t he fork and the struts themselves cut to a length to keep as much of the fo rk threaded as possible. I thank you for your educated explanation. Michael Perez Karetaker Aero www.karetakeraero.com --- On Tue=2C 1/11/11=2C hvandervoo@aol.com wrote: From: hvandervoo@aol.com Subject: Re: Pietenpol-List: Re: Wing Strut Fork End There are 3 factors that decide selection of the Fork-end of the main strut : 1) tension load=2C easily understood and both J-3 fork end and a Turnbuckle style fork can handle the required load. 2) compression load=2C often over looked but flying in turbulence often exp erienced=2C J-3 fork can handle this=2C Turnbuckle style can not. Remember that turnbuckles are designed for cable use=2C no compression load s there. 3) overlooked even more often is thread strength=2C diameter & length. For a steel fork end to work as designed the diameter should be same a as t he height of the nut insert (nut part to be of the same material) In other words a 5/16 Fork tread needs to have 5/16 nut height=2C if you ta p in to the strut your tread dept needs to be at least 5/16. Note: nut/ strut threads of the same steel material=2C more length is alwa ys better=2C rolled threads are better than cut/ tapped threads. I use the J-3 style fork end with steel struts and the weld-in treaded purp ose build nut insert. Now if you choose to use aluminum struts and tap your own treads be aware t hat aluminum has a lower tensile strength than steel. So compensate by tapping a deep/ long thread in to the best aluminum you ca n get. Your fork tread might not be long enough. You might need to consider a steel insert. Turnbuckles assemblies with brass center piece use the same principle=2C th e tread depth is much longer ( 6-8 X ) than the diameter of the tread. I did not sleep in a Holiday-inn express last night=2C but am a mechanical engineer by profession Hans NX15KV ________________________________ Message 58 ____________________________________ Time: 12:47:09 PM PST US From: Doug Dever Subject: RE: Pietenpol-List: Please Check My Math (alum.wing strut) As I understand aerodynamics and lift (limited) the lift pattern or distrib ution on a hershey bar wing is eliptical which means there is not as much l ift generated at the tips. This is also why washout is not needed=2C altho ugh many put some in. This would also imply that there is not as much lif t generated at the root either. This would mean that most of the lift would be generated in the middle 80% (paredo principle anyone.) From a design s implification standpoint to figure span loading (when designing spar streng th) The lift is considered equal along the span. We atmospheric guys desig n to yeild strength. The Space shuttle is the only thing I know of designe d to ultimate strength. In other words we are all splitting hairs as this is not Rocket science. The darn thing has flown for 80+years. Don't mess with a good thing. It works. Unless=2C of course you are an aeronautical engineer. Then go for it. Doug Dever In beautiful Stow Ohio From: cncampbell@windstream.net Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) EF Bruhn's book "Analysis and Design of Aircraft Structures" would disagree with your statement that more lift is generated from the inboard section t han the outboard sections. That would be true if the wing is tapered=2C bu t I'm looking at a diagram of a rectangular wing with spars of equal depth the entire length and the diagram of airload shows the same load on the tip as on the root. ----- Original Message ----- From: gliderx5@comcast.net Sent: Monday=2C January 10=2C 2011 11:19 PM Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) It has to do with the distribution of lift. More lift is generated from th e inboard section of the wing than the outboard sections. As a result ther e is less torque upward on the outer wing panels than if the lift was equal all of the way across the wing. This means that there is less force impos ed on the lift strut. Let me caution you a little in that I am a software engineer with great interest in aviation=2C NOT a mechanical or aerospace e ngineer=2C so I could be full of crap! But=2C I have friends that are aero nautical engineers and I have run this by them. Someone could argue the n umbers=2C but it should be very close. Malcolm Morrison http://home.comcast.net/~mmorrison123/ ----- Original Message ----- From: "Michael Perez" Sent: Monday=2C January 10=2C 2011 9:38:03 PM Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) et> What in your math is different then Jack's 3200? Your numbers are quite dif ferent? Michael Perez Karetaker Aero www.karetakeraero.com --- On Mon=2C 1/10/11=2C gliderx5@comcast.net wrote: > From: gliderx5@comcast.net > Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) > To: pietenpol-list@matronics.com > Date: Monday=2C January 10=2C 2011=2C 8:43 PM > #yiv909872567 p > {margin:0=3B}I > actually tried to determine these numbers a while back and > put them on my web site at > http://home.comcast.net/~mmorrison123/wing_loads.html > . It's probably a goofy thing to read=2C but I tried > to include the effect of an elliptical lift distribution=2C > which is what you have with a rectangular wing. > Adjusting my numbers up for a 1200 lb airplane at 4 Gs I get > about 1760 lbs on the strut ends. Should be a little > more on the front=2C and a little less on the rear. > > Malcolm Morrison > http://home.comcast.net/~mmorrison123.html > > ----- Original Message ----- > From: "Jack Phillips" > > To: pietenpol-list@matronics.com > Sent: Monday=2C January 10=2C 2011 1:09:25 PM > Subject: RE: Pietenpol-List: Please Check My Math > (alum.wing strut) > > > > > > > > > > > > > > > > > > > Michael=2C > how are you arriving at 1200 lbs > per strut at 4 G=92s? > > > > I could > see that if your struts were > vertical (in line with the lift load). They are not=2C > and since they are at an > angle from the horizontal=2C each strut will see a load equal > to the lift load at > that point divided by the sine of the angle. For most > Pietenpols=2C the angle is > about 30=B0 and the sine of 30=B0 is .50=2C so if all four > struts are carrying a > quarter of the total load (they=92re not ' the front > struts tend to > carry more than the rears=2C due to the position of the > center of pressure=2C and > the pressure distribution curve)=2C and the total load is > 4800 lbs=2C each strut is > carrying 1200/.5 or 2400 lbs. > > > > Without > knowing the pressure distribution > on the wing=2C I would assume for safety=92s sake that the > front struts are > carrying 2/3 of the load and the rear struts only > 1/3. If that is the case=2C > then the load at each front strut fitting on the wing at 4 > g=92s with a > 1200 lb gross weight would be 2/3 (2400) or 1600 lbs. > This is assuming that > each wing panel is generating half the lift or 2400 lbs=2C > and the centersection > is adding nothing=2C so again this is a conservative > assumption. If the lift > load at the front strut is 1600 lbs=2C the load in the strut > itself will be twice > that (if the angle is 30=B0) or 3200 lbs. Quite a bit > different than the 1200 > lbs you were calculating. > > > > Jack > Phillips > > NX899JP > =93Icarus Plummet=94 > > Raleigh=2C > NC > > > > > > > > > > > > From: > owner-pietenpol-list-server@matronics.com > [mailto:owner-pietenpol-list-server@matronics.com] > On Behalf Of Michael Perez > > Sent: Monday=2C > January 10=2C 2011 > 11:43 AM > > To: > pietenpol-list@matronics.com > > Subject: > Pietenpol-List: Please > Check My Math (alum.wing strut) > > > > > > > > > I am trying to > figure out bolt hole edge spacing for > my aluminum wing struts. These struts are the small > struts from Carlson > Aircraft. Doing the math=2C from the info. at the > site=2C I get a wall > thickness of the strut at .119". Since the > bolt would have to pull > through both walls=2C that number is now .238". > > > > I am going to assume that my plane's weight will be > 1000# and my weight will > be 200#. (I am 165# actually) for total weight of 1200#. > > > > The plans show using a 5/16" bolt. > (.3125") 2X bolt diameter > minus 1/2 of a bolt diameter yields a hole edge spacing > of .625 - > .15625 = .46875" > > > > .46875 X .238 (strut wall thickness) = .1115625 square > inches. > > > > .1115625 X 11637 (SHEAR listed on the website for the > small strut) = 1298 > lbs. > > > > My 1200# plane at 4Gs is 4800#. Each lift strut will see > about 1200 lbs each. > (?) > > > > My aluminum struts with the 2 diameter bolt edge spacing > should be able to > handle 1298 lbs each...which is good for a 1200# plane at > 4Gs. > > > > If I use an edge spacing of 1/2" even=2C then the new > number is 1384# per > strut. > > > > Thanks for any help advice. > > > > Michael Perez > > Karetaker Aero > > www.karetakeraero.com > > > > > > > > > > > > > > " > target="_blank">http://www.matronics.com/Navigator?Pietenpol-List > tp://forums.matronics.com > _blank">http://www.matronics.com/contribution > > &== href="http://www.matronics.com/Navigator?Pietenpol-List">http://www.matro nics.com/Navigator?Pietenpol-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c ________________________________ Message 59 ____________________________________ Time: 12:53:45 PM PST US Subject: Pietenpol-List: Re: Wing Strut Fork End Concerns From: "BYD" Okay Ryan, I'll put you down as a no. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=326575#326575 ________________________________ Message 60 ____________________________________ Time: 01:03:19 PM PST US Subject: Pietenpol-List: Re: Wing Strut Fork End Concerns From: "DOMIT" Be sure someone gets a video for YouTube if you try it. (That counts as a no) -------- Brad "DOMIT" Smith First rule of ground school: This is the ground... don't hit it going fast. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=326578#326578 ________________________________ Message 61 ____________________________________ Time: 01:36:11 PM PST US From: shad bell Subject: Re: Pietenpol-List: Re: 4130 tubing Man oh man, I ordered about $200-$300 of dillsburg tubing last year for my Jungster, I have been working on my cabanes and using 40 year old streamlin ed tubing made by Sumerhill (I think is the name on the tubing) made in the USA.- I am a litle leary now of using any of the round stock-from Dill sburg-for a flying machine, I guess I will have to do some experimenting on it. Shad =0A=0A=0A ________________________________ Message 62 ____________________________________ Time: 01:59:09 PM PST US Subject: Pietenpol-List: Re: wing strut fork ends From: "gtche98" Larry - Burning it would be environmentally disastrous. I have a much better solution. Just send me your address and I will come and take it off your hands and you will never have to worry about it again! :) Read this topic online here: http://forums.matronics.com/viewtopic.php?p=326581#326581 ________________________________ Message 63 ____________________________________ Time: 04:06:28 PM PST US Subject: Pietenpol-List: Re: Wing Strut Fork End From: "Bill Church" Michael wrote: "Ah, yeah, I read all posts related to my original question. This safety factor of 3, is that a standard factor or a number you came up with Bill?" and "I see the points of a few on this list and laugh at some of the others, but ..." I guess I must be one of the ones whose points you laugh at. Whatever... In response to your question, the FS of 3 is based on general engineering practice. I am a mechanical engineer, but not an aeronautical engineer, and have never claimed to be one, so I did a little research today, and have discovered that it is standard practice in aircraft design to use a Factor of safety of 1.5. This seems a little counter-intuitive, since the Factor of Safety used for aircraft design is half of that used in general practice, and only about one seventh that used for elevator cables (the things used to move people up and down in buildings, not the things at the back of the airplane). However, it has become a standard practice, because weight saving is critical for an aircraft to work. In order to be able to design inside this restrictive envelope, the aircraft has to operate within certain well-defined parameters (max speed, load, maneuvers, etc.). Additionally, the materials and practices used for aircraft manufacture are subject to stringent qualifications and standards (e.g. AN hardware, AC 43.13-1B, etc.). And finally, the actual aircraft are inspected more carefully and regularly than ordinary equipment. So, the short answer is that for aircraft design, the accepted minimum Factor of Safety is 1.5. And the limit load for normal aircraft use is +4g, which can be reached by recovering from a dive. Maybe not an activity that is planned, but conceivable that it could occur during normal flight. So the design load is then 6g. The Piper wing strut fittings may actually be slightly stronger than that required for this specific purpose, since the Piper struts have only one connection point at the bottom (Vee struts), but, as Jack explained, the front struts carry the larger portion of the load anyway. Since these fittings are readily available, and designed for this very purpose (wing strut fitting for an aircraft of similar size and function), why not use them? From the Aircraft Spruce website, the largest turnbuckle fork they list 161-80RS, which is rated for 8000 lb, the price is about $40. The Piper fork is about $85. $45 difference x 4 pcs = less than $200 "savings". Is it really worth it? It's been said that an engineer is someone that calculates to five decimal places, and then multiplies the final answer by 2. I guess that's me. I'd hate to see someone suffer for the sake of saving a few dollars. I'll shut up now. Bill C. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=326594#326594 ________________________________ Message 64 ____________________________________ Time: 04:27:13 PM PST US From: Ben Charvet Subject: Re: Pietenpol-List: LG at last Do you have any contact info for Ken? I noticed that Wag-Aero has struts for around $289, but I'd rather give Ken the business. Ben On 1/11/2011 9:14 AM, TOM STINEMETZE wrote: > *Ben:* > ** > *I purchased the spring struts with springs from Ken Perkins in > Olathe, KS. They came with the fork made up on one end. You adjust > to the length needed and make your own fork on the opposite end. > Takes a mighty good vice or other type of compressive device to > squeeze the die springs sufficiently to assemble them. I could not > tell that they compressed at all with me sitting in the plane and no > engine on the front.* > ** > *Tom* > *N328X* > > > >>> Ben Charvet 1/10/2011 7:07 PM >>> > I'm thinking of replacing my bungees with springs like you have. Did > you make the spring struts yourself, or buy them ready made? > > Ben Charvet > NX866BC > * > > > * ________________________________ Message 65 ____________________________________ Time: 05:02:48 PM PST US From: gliderx5@comcast.net Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) There's a book by Skip Smith, "An Illustrated Guide to Aerodymanics" that d oes a really great job of explaining lift and lift distribution. Here's a l ink to the spanwise lift distrubution section. http://books.google.com/book s?id=C8ZUBjtLXjEC&pg=PA40&lpg=PA40&dq=spanwise+lift+distribution&so urce=bl&ots=x-LHifhUYr&sig=fXe6_WzRfZekRoefbiyBFgd8EGg&hl=en&ei=C PosTfD6IMOblgfJ18CMCw&sa=X&oi=book_result&ct=result&resnum=6&ved= 0CD0Q6AEwBQ#v=onepage&q=spanwise%20lift%20distribution&f=false . The book has lots of pictures for people like me! Skip is a member of out local EAA chapter and a really great guy. Everyone should have this book. Malcolm Morrison http://home.comcast.net/~mmorrison123/ ----- Original Message ----- From: "Charles Campbell" Sent: Tuesday, January 11, 2011 1:19:27 PM Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) =EF=BB EF Bruhn's book "Analysis and Design of Aircraft Structures" would disagree with your statement that more lift is generated from the inboard section t han the outboard sections. That would be true if the wing is tapered, but I 'm looking at a diagram of a rectangular wing with spars of equal depth the entire length and the diagram of airload shows the same load on the tip as on the root. ----- Original Message ----- From: gliderx5@comcast.net Sent: Monday, January 10, 2011 11:19 PM Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) It has to do with the distribution of lift. More lift is generated from the inboard section of the wing than the outboard sections. As a result there is less torque upward on the outer wing panels than if the lift was equal a ll of the way across the wing. This means that there is less force imposed on the lift strut. Let me caution you a little in that I am a software engi neer with great interest in aviation, NOT a mechanical or aerospace enginee r, so I could be full of crap! But, I have friends that are aeronautical en gineers and I have run this by them. Someone could argue the numbers, but i t should be very close. Malcolm Morrison http://home.comcast.net/~mmorrison123/ ----- Original Message ----- From: "Michael Perez" Sent: Monday, January 10, 2011 9:38:03 PM Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) et> What in your math is different then Jack's 3200? Your numbers are quite dif ferent? Michael Perez Karetaker Aero www.karetakeraero.com --- On Mon, 1/10/11, gliderx5@comcast.net wrote: > From: gliderx5@comcast.net > Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) > To: pietenpol-list@matronics.com > Date: Monday, January 10, 2011, 8:43 PM > #yiv909872567 p > {margin:0;}I > actually tried to determine these numbers a while back and > put them on my web site at > http://home.comcast.net/~mmorrison123/wing_loads.html > . It's probably a goofy thing to read, but I tried > to include the effect of an elliptical lift distribution, > which is what you have with a rectangular wing. > Adjusting my numbers up for a 1200 lb airplane at 4 Gs I get > about 1760 lbs on the strut ends. Should be a little > more on the front, and a little less on the rear. > > Malcolm Morrison > http://home.comcast.net/~mmorrison123.html > > ----- Original Message ----- > From: "Jack Phillips" > > To: pietenpol-list@matronics.com > Sent: Monday, January 10, 2011 1:09:25 PM > Subject: RE: Pietenpol-List: Please Check My Math > (alum.wing strut) > > > > > > > > > > > > > > > > > > > Michael, > how are you arriving at 1200 lbs > per strut at 4 G=99s? > > > > I could > see that if your struts were > vertical (in line with the lift load). They are not, > and since they are at an > angle from the horizontal, each strut will see a load equal > to the lift load at > that point divided by the sine of the angle. For most > Pietenpols, the angle is > about 30=C2=B0 and the sine of 30=C2=B0 is .50, so if all four > struts are carrying a > quarter of the total load (they=99re not =93 the front > struts tend to > carry more than the rears, due to the position of the > center of pressure, and > the pressure distribution curve), and the total load is > 4800 lbs, each strut is > carrying 1200/.5 or 2400 lbs. > > > > Without > knowing the pressure distribution > on the wing, I would assume for safety=99s sake that the > front struts are > carrying 2/3 of the load and the rear struts only > 1/3. If that is the case, > then the load at each front strut fitting on the wing at 4 > g=99s with a > 1200 lb gross weight would be 2/3 (2400) or 1600 lbs. > This is assuming that > each wing panel is generating half the lift or 2400 lbs, > and the centersection > is adding nothing, so again this is a conservative > assumption. If the lift > load at the front strut is 1600 lbs, the load in the strut > itself will be twice > that (if the angle is 30=C2=B0) or 3200 lbs. Quite a bit > different than the 1200 > lbs you were calculating. > > > > Jack > Phillips > > NX899JP > =9CIcarus Plummet=9D > > Raleigh, > NC > > > > > > > > > > > > From: > owner-pietenpol-list-server@matronics.com > [mailto:owner-pietenpol-list-server@matronics.com] > On Behalf Of Michael Perez > > Sent: Monday, > January 10, 2011 > 11:43 AM > > To: > pietenpol-list@matronics.com > > Subject: > Pietenpol-List: Please > Check My Math (alum.wing strut) > > > > > > > > > I am trying to > figure out bolt hole edge spacing for > my aluminum wing struts. These struts are the small > struts from Carlson > Aircraft. Doing the math, from the info. at the > site, I get a wall > thickness of the strut at .119". Since the > bolt would have to pull > through both walls, that number is now .238". > > > > I am going to assume that my plane's weight will be > 1000# and my weight will > be 200#. (I am 165# actually) for total weight of 1200#. > > > > The plans show using a 5/16" bolt. > (.3125") 2X bolt diameter > minus 1/2 of a bolt diameter yields a hole edge spacing > of .625 - > .15625 = .46875" > > > > .46875 X .238 (strut wall thickness) = .1115625 square > inches. > > > > .1115625 X 11637 (SHEAR listed on the website for the > small strut) = 1298 > lbs. > > > > My 1200# plane at 4Gs is 4800#. Each lift strut will see > about 1200 lbs each. > (?) > > > > My aluminum struts with the 2 diameter bolt edge spacing > should be able to > handle 1298 lbs each...which is good for a 1200# plane at > 4Gs. > > > > If I use an edge spacing of 1/2" even, then the new > number is 1384# per > strut. > > > > Thanks for any help advice. > > > > Michael Perez > > Karetaker Aero > > www.karetakeraero.com > > > > > > > > > > > > > > " > target="_blank">http://www.matronics.com/Navigator?Pietenpol-List > tp://forums.matronics.com > _blank">http://www.matronics.com/contribution > > &=== href="http://www.matronics.com/Navigator?Pietenpol-List">http://www.matro nics.com/Navigator?Pietenpol-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c _ -======================== == ________________________________ Message 66 ____________________________________ Time: 05:14:42 PM PST US Subject: Re: Pietenpol-List: Re: Wing Strut Fork End From: Kenneth Howe If I may, I'll add my $.02. My disclaimer: I do have an aerospace engineering degree, but that was > 35 years ago, and I have not worked as an aero engineer (I got into computer software early on.) In dealing with aircraft structures you need to take into account both limit and ultimate loads, since our safety factor is a relatively slim 1.5. So the 4g we've been referencing here is the limit load to design to. At any load up to the point, everything in the structure must be able to withstand it without any permanent deformation (i.e. nothing can bend and take a permanent set.) The structure will bend and flex, but once you're back on the ground everything will spring back to the way it was. Now take all those loads you've calculated, multiply 'em by 1.5. Now every bit of the structure has to withstand those loads without failing, but they may take a permanent bend. Where this is important on our Piet's is that the difference in load between the yield point of wood and its breaking point is less than a factor of 1.5. So if your structure (such as wood struts) just meets the design limit loads, it's likely to break before reaching the ultimate loads. For most metals that we'll use, the difference between yield and breaking is greater than 1.5, so so can design to the 4g. I don't imagine many of us would intentionally stress a Pietenpol to 4g's, but as Bill said, various maneuvers could put you up there. Again, as Bill and Jack have mentioned, the front spar will carry more load than the rear, particularly at high angles of attack. And, if you ever hit those 4g's it will be at a high angle of attack. If you want to really get into the math, there was a good series of articles on stress analysis of a strut braced rectangular wing (Baby Ace) in Sport Aviation, Nov. & Dec. 1963, and Sept. 1965. (No, I'm not that old, but I do have a reprint of the articles in an old EAA publication, "Design, vol. 3". Another factor to consider is the category of the airplane. From what I remember (don't have any of my old texts on hand) normal category aircraft are designed to a limit load of 3.8g. Utility aircraft (Cessna 150/152 are I believe in the utility category, as is the Bonanza and others) are designed to 4g, and aerobatic aircraft to 6g. (Although most aerobatic aircraft are now designed and flown to loads well above 6g. The RedBull racers have pulled over 12g momentarily!) Ken On Jan 11, 2011, at 4:04 PM, Bill Church wrote: > > Michael wrote: > "Ah, yeah, I read all posts related to my original question. This safety factor of 3, is that a standard factor or a number you came up with Bill?" > and > "I see the points of a few on this list and laugh at some of the others, but ..." > > I guess I must be one of the ones whose points you laugh at. > Whatever... > > In response to your question, the FS of 3 is based on general engineering practice. > I am a mechanical engineer, but not an aeronautical engineer, and have never claimed to be one, so I did a little research today, and have discovered that it is standard practice in aircraft design to use a Factor of safety of 1.5. This seems a little counter-intuitive, since the Factor of Safety used for aircraft design is half of that used in general practice, and only about one seventh that used for elevator cables (the things used to move people up and down in buildings, not the things at the back of the airplane). However, it has become a standard practice, because weight saving is critical for an aircraft to work. In order to be able to design inside this restrictive envelope, the aircraft has to operate within certain well-defined parameters (max speed, load, maneuvers, etc.). Additionally, the materials and practices used for aircraft manufacture are subject to stringent qualifications and standards (e.g. AN hardware, AC 43.13-1B, etc.). And finally, the actual airc! > raft are inspected more carefully and regularly than ordinary equipment. > So, the short answer is that for aircraft design, the accepted minimum Factor of Safety is 1.5. And the limit load for normal aircraft use is +4g, which can be reached by recovering from a dive. Maybe not an activity that is planned, but conceivable that it could occur during normal flight. So the design load is then 6g. The Piper wing strut fittings may actually be slightly stronger than that required for this specific purpose, since the Piper struts have only one connection point at the bottom (Vee struts), but, as Jack explained, the front struts carry the larger portion of the load anyway. Since these fittings are readily available, and designed for this very purpose (wing strut fitting for an aircraft of similar size and function), why not use them? From the Aircraft Spruce website, the largest turnbuckle fork they list 161-80RS, which is rated for 8000 lb, the price is about $40. The Piper fork is about $85. $45 difference x 4 pcs = less than $200 "savings". Is it real! > ly worth it? > It's been said that an engineer is someone that calculates to five decimal places, and then multiplies the final answer by 2. I guess that's me. > I'd hate to see someone suffer for the sake of saving a few dollars. > I'll shut up now. > > Bill C. > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=326594#326594 > > > > > > > > > > ________________________________ Message 67 ____________________________________ Time: 06:08:08 PM PST US From: Michael Perez Subject: Pietenpol-List: Adjustable Wood Wing Strut Fitting For whomever it was asking, here is a simple drawing of a simple idea. There is a lot of room for change and improvement here, this was what I came up with right off the bat. Michael Perez Karetaker Aero www.karetakeraero.com ________________________________ Message 68 ____________________________________ Time: 06:56:38 PM PST US Subject: Pietenpol-List: Re: Tail wheel From: "blue213" Flyboy wrote: > I'm a new guy, woodshop teacher, building a Piet with 12 students. Our fuselage is making progress. What tailwheel is recommended for the Piet. We plan on using 600-6 tires and springs instead of bungee cords. Would appreciate any help possible. Flyboy from Berwick PA Hey Teach, can you hit enter every once in a while? :D -------- Blue Read this topic online here: http://forums.matronics.com/viewtopic.php?p=326621#326621 ________________________________ Message 69 ____________________________________ Time: 07:14:18 PM PST US From: "Greg Cardinal" Subject: Re: Pietenpol-List: Re: Wing Strut Fork End The article Ken mentions is located on Chris Tracy's website here: http://www.westcoastpiet.com/construction.htm Greg C. ----- Original Message ----- From: "Kenneth Howe" > If you want to really get into the math, there was a good series of articles on stress analysis of a strut braced rectangular wing (Baby Ace) in Sport Aviation, Nov. & Dec. 1963, and Sept. 1965. (No, I'm not that old, but I do have a reprint of the articles in an old EAA publication, "Design, vol. 3". > ________________________________ Message 70 ____________________________________ Time: 07:14:51 PM PST US From: "Ernie Moreno" Subject: Re: Pietenpol-List: steel Actually, we are building 5 DH-2's. Our first choice at this point is a 2276VW with a 2.5x1 belt redrive from Valley Engineering. This combo allows the use of 96x63 prop. This combo when tested gave 620 lbs. of statc thrust. I know it is not the same in the air, but I think that it will provide enough thrust to move 1000 gross aircraft through the air. Wing area is 256 square feet. Empty weight that I am shooting for is 690 to 710 lbs. It will carry approximately 15 gallons of fuel with up to a 250 lbs. pilot. There are some pictures of the project on EAA 292 chapter website. Ernie Moreno Noon Patrol Builder Group Piet 2431 ----- Original Message ----- From: Rick Holland To: pietenpol-list@matronics.com Sent: Tuesday, January 11, 2011 10:06 AM Subject: Re: Pietenpol-List: steel Wow, 4 DH-2s, neat aircraft, what engines are you planning on using? rick On Mon, Jan 10, 2011 at 10:07 PM, Ernie Moreno wrote: Had a conversation with my steel tube supplier today. For the record, my supplier is Tube Service in Portland Or. They advised me that there is 4130 Chromoly Steel available US made. It is available through a company called Wesco (is somewhere in Southern Calif.) and from Plymouth (in Arizona). From past experience I know that Plymouth does aluminium tubing also. My supplier agreed to replace all the Chinese tubing with made in USA tubing for no change in price. A great company. For the record I and four other individuals are building full size DH-2's. Using the basic Pietenpol specs on the gear, Ken Perkins hubs, 21"wheels with 21x3.25 tires. Ernie Moreno Piet 2431 " target="_blank">http://www.matronics.com/Navigator?Pietenpol-List tp://forums.matronics.com _blank">http://www.matronics.com/contribution -- Rick Holland Castle Rock, Colorado "Logic is a wreath of pretty flowers, that smell bad" ------------------------------------------------------------------------- ----- No virus found in this message. Checked by AVG - www.avg.com 01/11/11 ________________________________ Message 71 ____________________________________ Time: 07:14:57 PM PST US From: "Ernie Moreno" Subject: Re: Pietenpol-List: Re: 4130 tubing I note that tubing from the USA and Germany have a oily black look to them inside and out. the Chinese 4130 tubing has gray sandy look to it. On the lathe it does not cut smooth. It has a ASTM number as well as the dimensions on the tube but only on one end. It came with paperwork that said it matched the Mil Spec and ASTM standards. Ernie Moreno Piet 2431 ----- Original Message ----- From: "K5YAC" Sent: Tuesday, January 11, 2011 11:07 AM Subject: Pietenpol-List: Re: 4130 tubing > > Hmm, well then something doesn't jive. Either AS&S isn't getting their > tubing from Dillsburg, or Dillsburg isn't getting his tubing from China. > I hope the latter is true, but it could also explain why he is the > cheapest in the business. I'm about ready to build the kiddo a go-kart > out of this crap and plunk down the money for the good stuff, which I > thought I was getting. > > I'll look at my material to see if there are any markings that indicate > origin. I'll compare it to the stuff that I get from AS&S as well. I can > say this... in comparison to a few pieces of 4130 that we have at work, > the tubing I got from Dillsburg looks like gas pipe. The material at work > is from Jorgensen... the surfaces (especially inside) are very smooth and > shiny. Not the case with the Dillsburg tubing. In all fairness, I > haven't taken the time to cut and clean a piece up, but I think I might do > that this evening and bring it in tomorrow. > > Aww, the heck with it, I'm calling Vogelsong... > > Yep, I spoke to his secretary and she confirmed it... Chinese tubing. She > also told me that his son (mentioned in another thread) no longer works > for him. I said, "Imagine that." She came right out and said it... he > really doesn't care anymore. People have tried to talk to him, but he > makes it clear to them that he is in charge and the place will be run the > way he wants. I can somewhat understand that, but at some point it will > be run into the ground. > > Jorgensen says no way on Chinese tube... 70%-80% of their 4130 tubing is > domestic, but some comes from England, Germany or other European > locations. I'll be checking with Trident, AS&S and others just out of > curiosity. The Jorgensen rep did tell me to look closely at the line > marking and that it should state not only what type and dimension, but > what mill it was run at as well as what ATSM standard it meets. He also > said that we could line up tubing from 5 different vendors and that all of > them would look slightly different as far as finish, so that is no way to > compare. The only way to know for sure is to take samples to Sherry Labs > (local) and have them test it. I could probably reorder the entire batch > from a reputible outfit for less. > > -------- > Mark Chouinard > Wings, Center Section and Empannage framed up - Working on Fuselage > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=326552#326552 > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > ________________________________ Message 72 ____________________________________ Time: 07:35:38 PM PST US Subject: Pietenpol-List: Re: 4130 tubing From: "Piet2112" The tubing I got from AS&S was from both Benteler (Germany) and Plymouth Tube ProMoly (US). Curt Merdan Flower Mound, TX Read this topic online here: http://forums.matronics.com/viewtopic.php?p=326628#326628 ________________________________ Message 73 ____________________________________ Time: 07:55:32 PM PST US From: TOM MICHELLE BRANT Subject: RE: Pietenpol-List: Adjustable Wood Wing Strut Fitting should work - I may steal the idea myself - thanks for sharing. Tom B. From: speedbrake@sbcglobal.net Subject: Pietenpol-List: Adjustable Wood Wing Strut Fitting For whomever it was asking=2C here is a simple drawing of a simple idea. Th ere is a lot of room for change and improvement here=2C this was what I cam e up with right off the bat. Michael Perez Karetaker Aero www.karetakeraero.com ________________________________ Message 74 ____________________________________ Time: 08:02:39 PM PST US From: Kip and Beth Gardner Subject: Re: Pietenpol-List: Adjustable Wood Wing Strut Fitting Thanks Michael, good start! KIp Gardner On Jan 11, 2011, at 9:05 PM, Michael Perez wrote: > For whomever it was asking, here is a simple drawing of a simple > idea. There is a lot of room for change and improvement here, this > was what I came up with right off the bat. > > Michael Perez > Karetaker Aero > www.karetakeraero.com > ________________________________ Message 75 ____________________________________ Time: 08:18:04 PM PST US Subject: Pietenpol-List: Re: Adjustable Wood Wing Strut Fitting From: "DOMIT" Nice! I might steal that for the project I'm involved with. -------- Brad "DOMIT" Smith First rule of ground school: This is the ground... don't hit it going fast. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=326632#326632 ________________________________ Message 76 ____________________________________ Time: 08:21:37 PM PST US From: "Clif Dawson" Subject: Re: Pietenpol-List: Please Check My Math (alum.wing strut) Yes, but I was replying to the message referenced from Malcolm. And the whole thing started with Michael's question regarding the lift strut forces. So both this chart and the info your guessing at, which would have to come from research info on the Bernard airfoil, are important. We don't have the airfoil info, only that from similiar ones like the Jenny's. The rear strut is actually quite far forward Making it relatively close to the center of pressure. With the allowable CG being between 15" and 20" then we can assume the CP to fall near the center of that range. The front strut is 7" from the LE making it 10 to 11" ahead of the CP. The rear spar is 36" from the LE making it 18 to 19" from the CP so the front spar takes between 10/19ths to 11/18ths of the load. Two thirds is 66% and 11/18ths is 0.62, pretty close to 2/3rds. So, Jack, using your guess provides a bit of safety factor. Pretty good guesstimating. :-) Clif "Education: the path from cocky ignorance to miserable uncertainty." - Mark Twain, writer and humorist My guess was that it carrries 2/3 of the load and the rear spars only 1/3, but this is only a GUESS. It may be carrying much more of the load than that. It might be carrying =BE of the load. In Michael's case, the best thing to do is to build his plane with the cheap fittings, then load it to gross weight and subject it to maneuvers which induce 6 G's and see if he dies in the test. If he doesn't die, then it was OK. Jack Phillips NX899JP "Icarus Plummet" Raleigh, NC ________________________________ Message 77 ____________________________________ Time: 08:22:03 PM PST US From: Owen Davies Subject: Re: Pietenpol-List: Adjustable Wood Wing Strut Fitting I'd give some thought to plating each side of the strut with plywood and moving the bolts further up. As it is drawn, the end-most bolt almost surely would rip out the moment it took any stress. The basic concept looks good, though. (No doubt you guys knew all that, of course, but just in case....) Owen ________________________________ Message 78 ____________________________________ Time: 08:22:09 PM PST US Subject: Pietenpol-List: Re: Wing Strut Fork End From: "DOMIT" ken(at)cooper-mtn.com wrote: > Another factor to consider is the category of the airplane. From what I remember (don't have any of my old texts on hand) normal category aircraft are designed to a limit load of 3.8g. Utility aircraft (Cessna 150/152 are I believe in the utility category, as is the Bonanza and others) are designed to 4g, and aerobatic aircraft to 6g. (Although most aerobatic aircraft are now designed and flown to loads well above 6g. The RedBull racers have pulled over 12g momentarily!) > > Ken > > On Jan 11, 2011, at 4:04 PM, Bill Church wrote: > > > > > > > > Correction: The 150/152 are in the "Oh my GOD that's ugly" catagory. They don't have to worry about air loads, they don't fly by aerodynamic laws. They're so ugly they repel the earth. > > Michael wrote: > > "Ah, yeah, I read all posts related to my original question. This safety factor of 3, is that a standard factor or a number you came up with Bill?" > > and > > "I see the points of a few on this list and laugh at some of the others, but ..." > > > > I guess I must be one of the ones whose points you laugh at. > > Whatever... > > > > In response to your question, the FS of 3 is based on general engineering practice. > > I am a mechanical engineer, but not an aeronautical engineer, and have never claimed to be one, so I did a little research today, and have discovered that it is standard practice in aircraft design to use a Factor of safety of 1.5. This seems a little counter-intuitive, since the Factor of Safety used for aircraft design is half of that used in general practice, and only about one seventh that used for elevator cables (the things used to move people up and down in buildings, not the things at the back of the airplane). However, it has become a standard practice, because weight saving is critical for an aircraft to work. In order to be able to design inside this restrictive envelope, the aircraft has to operate within certain well-defined parameters (max speed, load, maneuvers, etc.). Additionally, the materials and practices used for aircraft manufacture are subject to stringent qualifications and standards (e.g. AN hardware, AC 43.13-1B, etc.). And finally, the actual airc! > > raft are inspected more carefully and regularly than ordinary equipment. > > So, the short answer is that for aircraft design, the accepted minimum Factor of Safety is 1.5. And the limit load for normal aircraft use is +4g, which can be reached by recovering from a dive. Maybe not an activity that is planned, but conceivable that it could occur during normal flight. So the design load is then 6g. The Piper wing strut fittings may actually be slightly stronger than that required for this specific purpose, since the Piper struts have only one connection point at the bottom (Vee struts), but, as Jack explained, the front struts carry the larger portion of the load anyway. Since these fittings are readily available, and designed for this very purpose (wing strut fitting for an aircraft of similar size and function), why not use them? From the Aircraft Spruce website, the largest turnbuckle fork they list 161-80RS, which is rated for 8000 lb, the price is about $40. The Piper fork is about $85. $45 difference x 4 pcs = less than $200 "savings". Is it real! > > ly worth it? > > It's been said that an engineer is someone that calculates to five decimal places, and then multiplies the final answer by 2. I guess that's me. > > I'd hate to see someone suffer for the sake of saving a few dollars. > > I'll shut up now. > > > > Bill C. > > > > > > > > > > Read this topic online here: > > > > http://forums.matronics.com/viewtopic.php?p=326594#326594 > > > > > > > > > > > > > > > > > > > > > > > > > :P -------- Brad "DOMIT" Smith First rule of ground school: This is the ground... don't hit it going fast. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=326633#326633 ________________________________ Message 79 ____________________________________ Time: 08:41:30 PM PST US From: "amsafetyc@aol.com" Subject: Re: Pietenpol-List: Adjustable Wood Wing Strut Fitting Which is the reason for embedded metal at each end and midway not halfway points able to hold thru bolting with less chance of tearing out. Taking advantage of experienced builder comments on setting up a vibration at jury strut location half way rather than a sorta midway offset position. Its that safety thing in me that says a little metalic insurance is not a bad thing even with a nominal weight penalty its peace of mind assurance. John Sent via DROID on Verizon Wireless -----Original message----- From: Owen Davies Sent: Wed, Jan 12, 2011 04:22:17 GMT+00:00 Subject: Re: Pietenpol-List: Adjustable Wood Wing Strut Fitting I'd give some thought to plating each side of the strut with plywood and moving the bolts further up. As it is drawn, the end-most bolt almost surely would rip out the moment it took any stress. The basic concept looks good, though. (No doubt you guys knew all that, of course, but just in case....) Owen ________________________________ Message 80 ____________________________________ Time: 09:10:00 PM PST US From: Owen Davies Subject: Re: Pietenpol-List: Adjustable Wood Wing Strut Fitting On 1/11/2011 11:36 PM, amsafetyc@aol.com wrote: > Which is the reason for embedded metal at each end and midway not > halfway points able to hold thru bolting with less chance of tearing > out. Taking advantage of experienced builder comments on setting up a > vibration at jury strut location half way rather than a sorta midway > offset position. Sorry, I must have missed something in the drawing. Owen ________________________________ Message 81 ____________________________________ Time: 10:31:02 PM PST US Subject: Pietenpol-List: Re: BPA article From: "bubbleboy" I would love to join...if it was more join friendly for international people! Why cant they accept Paypal? Everyone else does. An international draft costs twice what the subscription is! Ok...my whinge over for the day! Scotty 8) -------- Scotty Tamworth, Australia Building a Corvair Powered Pietenpol Air Camper www.scottyspietenpol.com Read this topic online here: http://forums.matronics.com/viewtopic.php?p=326642#326642 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message pietenpol-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Pietenpol-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/pietenpol-list Browse Digests http://www.matronics.com/digest/pietenpol-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.