---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Thu 10/08/09: 46 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:12 AM - thanks all (Douwe Blumberg) 2. 02:13 AM - straight axle bungees (Douwe Blumberg) 3. 04:43 AM - Re: one/three piece wing (helspersew@aol.com) 4. 04:55 AM - Re: Re: Spring Gear (Jack) 5. 05:11 AM - Re: control cable exit holes (Gene Rambo) 6. 05:14 AM - Re: thanks all (Dan Yocum) 7. 05:25 AM - Re: tailwheel springs (Gene Rambo) 8. 05:57 AM - hickory wood (Oscar Zuniga) 9. 05:57 AM - Re: control cable exit holes (Jack Phillips) 10. 06:10 AM - Re: straight axle bungees (Bill Church) 11. 06:13 AM - Re: tailwheel springs (Doug Dever) 12. 06:24 AM - Re: Spring Gear (Jeff Boatright) 13. 06:27 AM - Re: Re: Spring Gear (JERRY GROGAN) 14. 06:46 AM - Re: hickory wood (Bill Church) 15. 06:49 AM - Re: Re: Spring Gear (Bill Church) 16. 09:19 AM - Re: control cable exit holes (shad bell) 17. 09:37 AM - Re: Spring Gear (Bill Church) 18. 10:19 AM - Re: control cable exit holes (Lagowski Morrow) 19. 10:19 AM - Re: tailwheel springs (Ryan Mueller) 20. 11:19 AM - Re: Spring Gear (steven sadler) 21. 12:11 PM - Vi Kaplar's Pietenpols (Perry Rhoads) 22. 12:11 PM - Re: Spring Gear (hvandervoo@aol.com) 23. 12:39 PM - Re: Spring Gear (Bill Church) 24. 12:52 PM - Re: Vi Kaplar's Pietenpols (Jim Markle) 25. 01:08 PM - Re: bell crank spring for trim control (KMHeide, BA, CPO, FAAOP) 26. 01:22 PM - Re: toasting-- Jimmy Doolittle style (Baldeagle) 27. 01:22 PM - Re: Front cowling for the pietenpol (KMHeide, BA, CPO, FAAOP) 28. 02:38 PM - Re: control cable exit holes (Dan Yocum) 29. 02:48 PM - Vi Kapler's Piets (Oscar Zuniga) 30. 03:37 PM - Cable exits (helspersew@aol.com) 31. 04:54 PM - Re: Re: Spring Gear (Jack) 32. 05:08 PM - Re: Re: Spring Gear (Jack) 33. 05:22 PM - Re: Spring Gear (steven sadler) 34. 06:51 PM - Javier is back ! (Cuy, Michael D. (GRC-RXD0)[ASRC Aerospace Corporation]) 35. 06:54 PM - Spring Gear (Oscar Zuniga) 36. 07:21 PM - Re: hickory wood (Robert Ray) 37. 07:21 PM - Re: tailwheel springs (Clif Dawson) 38. 07:41 PM - Re: hickory wood (Clif Dawson) 39. 07:42 PM - Re: hickory wood (Clif Dawson) 40. 08:04 PM - Re: Spring Gear (Ryan Mueller) 41. 08:04 PM - Re: Re: Front cowling for the pietenpol (shad bell) 42. 08:11 PM - Re: hickory wood (Ryan Mueller) 43. 08:18 PM - hickory wood (Oscar Zuniga) 44. 08:29 PM - Re: hickory wood (Robert Ray) 45. 09:12 PM - Re: Javier is back ! (Javier Cruz) 46. 10:14 PM - Re: hickory wood ok (jorge lizarraga) ________________________________ Message 1 _____________________________________ Time: 02:12:58 AM PST US From: "Douwe Blumberg" Subject: Pietenpol-List: thanks all Thank you all for your advice, we really have a great resource of knowledge with this group. Should probably use springs, but I was planning on putting them behind the pilot seat. I will use split bolts to affix the tailwheel cable to the rudder cable, and after about eight inches or so, will splice in the springs so they don't interfere with the rudder cable itself. A nice benefit of this (stolen from Larry Williams) is that the split bolts are adjusted to become your rudder stops. They simply hit the bulkhead and stop the rudder travel. I think Larry said he installed a little plywood disk loosely there. A rubber doughnut would work too. One could also precut some cloth patches to cover the cable exit holes, pink them, spray them and glue them on using any number of glues. This would save a few grams by the tail, and be inconspicuous. Douwe ________________________________ Message 2 _____________________________________ Time: 02:13:39 AM PST US From: "Douwe Blumberg" Subject: Pietenpol-List: straight axle bungees The other day I came across some photos of WWI german airplanes where the landing gear bungees had been replaced with long coil springs wrapped around the axle in a similar manner. I am assuming this expedient was due to their rubber shortage, but it set me thinking... Though heavier, I wonder if it would work. Over the years, I've heard of two incidents with straight axle gears due to broken bungees. Stainless steel springs can be had which would virtually eliminate worry over aging bungees and the headache of replacing them every so often. I wonder how much heavier it would be. Douwe ________________________________ Message 3 _____________________________________ Time: 04:43:20 AM PST US Subject: Re: Pietenpol-List: one/three piece wing From: helspersew@aol.com Santiago, my hat's off to you. That is the best and simplest spar splice jig I have ever seen. Can't get any better. Dan H -----Original Message----- From: santiago morete Sent: Wed, Oct 7, 2009 10:00 pm Subject: Pietenpol-List: one/three piece wing Dallas, We used this simple jig to make the 15:1?scarf.? Very easy, fast and accurate. Saludos ? Santiago ? Encontra las mejores recetas con Yahoo! Cocina. http://ar.mujer.yahoo.com/cocina/ ________________________________ Message 4 _____________________________________ Time: 04:55:01 AM PST US From: "Jack" Subject: RE: RE: Pietenpol-List: Spring Gear Thanks so much to all, valuable input! Jack www.textors.com Very close, Jeff. You would need to add the diameter of the cross bolt that holds the spring. Since the cross bolt is already in the slot, it will need to be able to move the full compression of the spring. That will give the MINIMUM length the slot should be. Bill C. -----Original Message----- From: owner-pietenpol-list-server@matronics.com on behalf of Jeff Boatright Sent: Wed 07/10/2009 9:24 PM Subject: Re: Pietenpol-List: Spring Gear I may be off on this, probably am, but it seems to me that the space between the spring spirals add up to the entire distance that the spring can compress. If so, then that's how long the slot needs to be, right? > > >Jack I made my shock struts per Bill Reweys drawing for spring >struts. The slot is 2.75" long on my struts. I have not flown them >yet but with 6" springs this seems like a better slot length. Get >the packet of Pietenpol tips and hints direct from Bill. >Jim B. > >Jim Boyer >Santa Rosa, CA >Pietenpol builder with Corvair > >Oct 7, 2009 11:44:15 AM, pietenpol-list@matronics.com wrote: > >All, >Can you assist with a question on spring gear? The attached photo >is from Tony's book. He states that the slot is 1 3/4" long. Does >that sound like enough travel? >Thanks, >Jack >www.textors.com Checked by AVG - www.avg.com 05:18:00 ________________________________ Message 5 _____________________________________ Time: 05:11:26 AM PST US From: "Gene Rambo" Subject: Re: Pietenpol-List: control cable exit holes if the cut is truly accurate, there is no need for any kind of patch, but only if you put a piece of fabric as a doubler at the exit point. It kind of looks better without one, and if there is no side tearing movement, it will never grow. Gene ----- Original Message ----- From: Douwe Blumberg To: pietenpolgroup Sent: Wednesday, October 07, 2009 8:18 AM Subject: Pietenpol-List: control cable exit holes > I am looking at where my control cables exit the fuselage and run back to the "flippers". Most people seem to glue some leather patches over them, but I was wondering... The slits I made in the fuse covering were pretty accurate, Can I simply leave the slits as they are? or will they gradually tear and enlarge in the slipstream? Douwe http://www.matronics.com/Navigator?Pietenpol-List http://www.matronics.com/contribution ________________________________ Message 6 _____________________________________ Time: 05:14:10 AM PST US From: Dan Yocum Subject: Re: Pietenpol-List: thanks all Douwe, Douwe Blumberg wrote: > One could also precut some cloth patches to cover the cable exit holes, pink > them, spray them and glue them on using any number of glues. This would > save a few grams by the tail, and be inconspicuous. Note in the pictures that fabric patches is what was done on Le Turtle N8031 and the fabric still ripped and frayed. Dan PS, yes La Tortue would be the proper French translation - I'm still working on the name. ;-) -- Dan Yocum Fermilab 630.840.6509 yocum@fnal.gov, http://fermigrid.fnal.gov Fermilab. Just zeros and ones. ________________________________ Message 7 _____________________________________ Time: 05:25:02 AM PST US From: "Gene Rambo" Subject: Re: Pietenpol-List: tailwheel springs I think the springs also help eliminate shimmying, although logically you would think it would increase it. Just think, ALL Cubs, Champs, Taylorcrafts, Cessnas, etc, etc, etc use them. There MUST be a good reason. Gene ----- Original Message ----- From: Douwe Blumberg To: pietenpolgroup Sent: Wednesday, October 07, 2009 8:24 AM Subject: Pietenpol-List: tailwheel springs > One more thing... There was some talk (writing??) awhile back about not using tailwheel springs and it set me to thinking. What would happen if one didn't use springs, just straight cables? Obviously, bumps and jerks will be transmitted directly to the rudder bar, which is about the only downside I can see. Seems like you'd get rid of some potential uncontrolled movement back there without springs, and you'd save a few ounces. In you flyer's experiences, how bad can the bumps and jerks be from the tailwheel, and what do you think of this idea? Thanks Douwe, ps: finished windscreens, now doing leather cockpit coaming, which is very rewarding. Got the Red Baron thing going!! http://www.matronics.com/Navigator?Pietenpol-List http://www.matronics.com/contribution ________________________________ Message 8 _____________________________________ Time: 05:57:47 AM PST US From: Oscar Zuniga Subject: Pietenpol-List: hickory wood Jorge; I think hickory wood is what is commonly used foraxe handles. You can also use ash if you are making cabane struts from wood. You could probably also use oak. Speaking of hickory axe handles, and going back to earlier posts about making the wing tip bows out of something durable to resist groundloop scrapes, you could also install axe handle outriggers like the tri-wing Fokker airplanes had, to do the same thing. Sort of like training wheels ;o) Oscar Zuniga Air Camper NX41CC San Antonio, TX mailto: taildrags@hotmail.com website at http://www.flysquirrel.net ________________________________ Message 9 _____________________________________ Time: 05:57:47 AM PST US From: "Jack Phillips" Subject: RE: Pietenpol-List: control cable exit holes PolyTak -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of Dan Yocum Sent: Wednesday, October 07, 2009 3:19 PM Subject: Re: Pietenpol-List: control cable exit holes Douwe, Indeed, the holes will rip and tatter. See the following: http://5n429glenoak.homelinux.net/gallery/N8031/img_2580 and a few pictures onward from there... Which leads to my follow-on question since I have no fabric experience yet - how does one glue on leather reinforcment patches? Superglue? Epoxy? How does one prepare the fabric? Thanks, Dan Ryan Mueller wrote: > Douwe, > > The holes will most likely enlarge and tatter over time, with the > cables moving back and forth through the holes , and vibrating around a > bit in the slipstream. The leather patches, or whatever reinforcement > you choose, can be installed at any time however, so if you want to > leave them off and see how things wear I wouldn't think there would be > any harm in that. Make the holes a preflight item, and if they start to > enlarge then you know you need to install the patches. > > Ryan > > On Wed, Oct 7, 2009 at 7:18 AM, Douwe Blumberg > > wrote: > > > > > I am looking at where my control cables exit the fuselage and run > back to > the "flippers". Most people seem to glue some leather patches over > them, > but I was wondering... > > The slits I made in the fuse covering were pretty accurate, Can I > simply > leave the slits as they are? or will they gradually tear and > enlarge in the > slipstream? > > Douwe -- Dan Yocum Fermilab 630.840.6509 yocum@fnal.gov, http://fermigrid.fnal.gov Fermilab. Just zeros and ones. ________________________________ Message 10 ____________________________________ Time: 06:10:13 AM PST US Subject: RE: Pietenpol-List: straight axle bungees From: "Bill Church" Douwe, Do you mean the springs were used as bungees? Long springs wrapped in the same manner as bungees? I would imagine that set-up would have its own bunch of problems, even more troublesome than the rubber bungees. I think the springs would become entangled as they were stretched, side-by-side, and jostled around, ending up with a tangled mess. And springs break too - not just bungees. Do you have one of those photos to share? Just curious as to what it looked like. Bill C. -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of Douwe Blumberg Sent: Thursday, October 08, 2009 5:11 AM Subject: Pietenpol-List: straight axle bungees --> The other day I came across some photos of WWI german airplanes where the landing gear bungees had been replaced with long coil springs wrapped around the axle in a similar manner. I am assuming this expedient was due to their rubber shortage, but it set me thinking... Though heavier, I wonder if it would work. Over the years, I've heard of two incidents with straight axle gears due to broken bungees. Stainless steel springs can be had which would virtually eliminate worry over aging bungees and the headache of replacing them every so often. I wonder how much heavier it would be. Douwe ________________________________ Message 11 ____________________________________ Time: 06:13:00 AM PST US From: Doug Dever Subject: RE: Pietenpol-List: tailwheel springs Gene=2C There must be a good reason you can't put full fuel=2C pax and baggage in m ost cert. aircraft either. I can't figure it out. Doug Dever In beautiful Stow Ohio From: generambo@msn.com Subject: Re: Pietenpol-List: tailwheel springs I think the springs also help eliminate shimmying=2C although logically you would think it would increase it. Just think=2C ALL Cubs=2C Champs=2C Tay lorcrafts=2C Cessnas=2C etc=2C etc=2C etc use them. There MUST be a good r eason. Gene ----- Original Message ----- From: Douwe Blumberg Sent: Wednesday=2C October 07=2C 2009 8:24 AM Subject: Pietenpol-List: tailwheel springs link.net> One more thing... There was some talk (writing??) awhile back about not using tailwheel springs and it set me to thinking. What would happen if one didn't use springs=2C just straight cables? Obviously=2C bumps and jerks will be transmitted directly to the rudder bar =2C which is about the only downside I can see. Seems like you'd get rid of some potential uncontrolled movement back there without springs=2C and you' d save a few ounces. In you flyer's experiences=2C how bad can the bumps and jerks be from the tailwheel=2C and what do you think of this idea? Thanks Douwe=2C ps: finished windscreens=2C now doing leather cockpit coaming=2C which is v ery rewarding. Got the Red Baron thing nbsp=3B Features Chat=2C http://w ww.matnbsp=3B via the Web title=http://forums.matronics.com/ href=" http://forums.matronics.com">http://forums.matronics.com _p=3B generous bsp=3B title=http://www.matroni cs.com/contribution href="http://www.matronics.com/contribution">http://w ww.matronics.com/c================ =0A _________________________________________________________________=0A Hotmail: Trusted email with Microsoft=92s powerful SPAM protection.=0A ________________________________ Message 12 ____________________________________ Time: 06:24:41 AM PST US From: Jeff Boatright Subject: RE: Pietenpol-List: Spring Gear Bill, Yep, that's right. Of course, in my case, after a few landings a less-than-minimal slot will have been wallered out... =-O Jeff >Very close, Jeff. >You would need to add the diameter of the cross bolt that holds the spring. >Since the cross bolt is already in the slot, it will need to be able >to move the full compression of the spring. >That will give the MINIMUM length the slot should be. > >Bill C. > >-----Original Message----- >From: owner-pietenpol-list-server@matronics.com on behalf of Jeff Boatright >Sent: Wed 07/10/2009 9:24 PM >To: pietenpol-list@matronics.com >Subject: Re: Pietenpol-List: Spring Gear > > >I may be off on this, probably am, but it seems to me that the space >between the spring spirals add up to the entire distance that the >spring can compress. If so, then that's how long the slot needs to >be, right? ________________________________ Message 13 ____________________________________ Time: 06:27:50 AM PST US From: "JERRY GROGAN" Subject: Re: RE: Pietenpol-List: Spring Gear Jack I think I have a set of the spring gear here at the shop, done you could look at. I would need to dig a little but we have one made for the Smith Miniplane. And it can only traval as much as the slot is long. But that is all the spring can traval anyway. Jerry Sky Classic Aircraft ----- Original Message ----- From: "Jack" Sent: Thursday, October 08, 2009 6:14 AM Subject: RE: RE: Pietenpol-List: Spring Gear > > Thanks so much to all, valuable input! > Jack > www.textors.com > > > Very close, Jeff. > You would need to add the diameter of the cross bolt that holds the > spring. > Since the cross bolt is already in the slot, it will need to be able to > move > the full compression of the spring. > That will give the MINIMUM length the slot should be. > > Bill C. > > -----Original Message----- > From: owner-pietenpol-list-server@matronics.com on behalf of Jeff > Boatright > Sent: Wed 07/10/2009 9:24 PM > To: pietenpol-list@matronics.com > Subject: Re: Pietenpol-List: Spring Gear > > > I may be off on this, probably am, but it seems to me that the space > between the spring spirals add up to the entire distance that the > spring can compress. If so, then that's how long the slot needs to > be, right? > >> >> >>Jack I made my shock struts per Bill Reweys drawing for spring >>struts. The slot is 2.75" long on my struts. I have not flown them >>yet but with 6" springs this seems like a better slot length. Get >>the packet of Pietenpol tips and hints direct from Bill. >>Jim B. >> >>Jim Boyer >>Santa Rosa, CA >>Pietenpol builder with Corvair >> >>Oct 7, 2009 11:44:15 AM, pietenpol-list@matronics.com wrote: >> >>All, >>Can you assist with a question on spring gear? The attached photo >>is from Tony's book. He states that the slot is 1 3/4" long. Does >>that sound like enough travel? >>Thanks, >>Jack >>www.textors.com > > > Checked by AVG - www.avg.com > 05:18:00 > > > ________________________________ Message 14 ____________________________________ Time: 06:46:33 AM PST US Subject: RE: Pietenpol-List: hickory wood From: "Bill Church" For the loads imposed on the cabane struts (only about 50 pounds or so, each), ALMOST any type of wood would likely be sufficient. I wrote the word "almost" in caps to avoid having anyone following up with wiseguy suggestions like using spalted burls for the cabanes (well, that's what I would probably do anyway). Cabane struts made of Spruce can handle the loads - provided an adequate cross-section is used, and the connection details are also properly thought out. Actually, the connection details are likely more important than the species of wood used. Substituting wood cabanes for the streamline steel shown in the plans is a structural change, so of course, anyone proposing making a change like this should either do the calculations themselves (if they are qualified), or have them done by someone who is qualified. Don't mess with it if you don't know what you're doing. I don't have the info at my fingertips, but as I recall, if made of 4130, the cabanes could be as small as (maybe) 1/2" diameter tube (?) to carry the loads imposed on them. But they would look stupid. Visually they would not appear to be correct. Bill C. ________________________________ Message 15 ____________________________________ Time: 06:49:16 AM PST US Subject: RE: RE: Pietenpol-List: Spring Gear From: "Bill Church" Not to be a wiseguy, but that's no coincidence. The slot length would be by design - determined by the spring travel. Making the slot length to allow the crossbolt travel to be equal to, or "slightly" longer than the distance the spring will travel is okay. Making the slot length to allow the crossbolt travel to be less than the distance the spring will travel is not okay. Bill C. -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of JERRY GROGAN Sent: Thursday, October 08, 2009 9:27 AM Subject: Re: RE: Pietenpol-List: Spring Gear --> ... And it can only traval as much as the slot is long. But that is all the spring can traval anyway. Jerry Sky Classic Aircraft ________________________________ Message 16 ____________________________________ Time: 09:19:37 AM PST US From: shad bell Subject: RE: Pietenpol-List: control cable exit holes Anothe methood is to sew the leather to a piece of fabric, then glue the fa bric to the fabric, then it wont peel off with age due to drying out or shr inkage of the leather.- Just make a teardrop shaped leather exit patch, a nd then make a fabric patch that is 1 inch bigger all the way around the pe rimeter, then stich the leather to the fabric, and then glue the fabric/lea ther patch to the airplane.- I think this might stick better because fabr ic glues are best suited to glue dacron to dacron.- I will admit though m ost airplanes I see do have the leather patches just glued on.- Some I se e are peeling off some don't.- I have also seen a trick where people will laminate a piece of 1/16 plywood between the backside of the fabric, and c over the ply to make a fabric-ply-fabric sandwich for cable exits.- This seems to give the cleanest instalation, but I think the leather route looks the most time period correct for a piet. - Probably 100 other methoods of doing it, Shad=0A=0A=0A ________________________________ Message 17 ____________________________________ Time: 09:37:43 AM PST US Subject: RE: Pietenpol-List: Spring Gear From: "Bill Church" Yes, Jack, you're messed up. Just kidding... I can't resist when given an opportunity like that. Your thinking is not off base, really. The physical limit of the travel will be controlled by one of two things: A. the length of the slot, or B. The compressed length of the spring. Most people need to look at this landing gear arrangement for a little while to figure out exactly how it works. When you see it working, it makes sense, but looking at the drawing, it seems a bit confusing. While the configuration of the landing gear will put the diagonal strut in tension when loaded, this design uses a compression spring to absorb the load. Compression springs have two limiting dimensions. One is the free length, or unloaded length, which is the length before installing (easy to measure), with no loads imposed on it. The other is the fully compressed length, which is when there are no more gaps between the coils, and the spring can not compress any further. When this point is reached, it will not matter if the slot is any longer, because the spring will not squish any more. As an example, the spring specified in Hans' drawing has an Aircraft Spruce part number (06-13200) http://www.aircraftspruce.com/catalog/lgpages/shockabsorb.php . The other number (9-3224-36) is likely the manufacturer's part number, as these springs are called Die Springs, and are used for machinery such as punch presses. A little internet searching gives us the following catalog from the manufacturer (Danly) http://www.danly.com/PDFs/IEM-DieMaxSprings.pdf . Page 13 of the catalog has the particular spring listed, near the bottom of the page. The spring diameter is 2", the Free length is 6", and the total travel to solid is 1.78" at a load of 2593 pounds. The MINIMUM length of the slot would be this length PLUS the diameter of the cross bolt (in this case 5/16"), which comes out to just over 2". It is better to rely on the spring as the limiting factor rather than the slot length, so the slot is made a little longer than 2". If the set-up made use of an Extension spring, rather than a Compression spring, there would not really be a maximum length for the loaded spring, since in theory, one could stretch the spring out till it was just a straight piece of wire. So, in that case, the length of the slot would be the limiting factor. Exrension springs are not really manufactured to handle large loads like this, so they are not really an option for this application. Don't know if that made things clearer, or more confusing for you. Bill C. (by the way, my original plan was to build the split gear (it likely would be better for rough fields), but I just prefer the look of the old wooden gear more) ________________________________ From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of Jack Sent: Wednesday, October 07, 2009 5:37 PM Subject: RE: Pietenpol-List: Spring Gear Bill, As usual, fantastic information, thanks. I too was going with the straight (do you want mine) axle but feel the split will be better for rough fields. Sorry Mike, Jack, Bill, ET AL. Not being an Engineer and not too bright...I must not fully understand the operation of the strut. It seems to me no matter the weight, bounce or spring tension, It looks like the travel will be limited the slot length. Am I messed up? Thanks! Jack www.textors.com ________________________________ From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of Bill Church Sent: Wednesday, October 07, 2009 3:04 PM Subject: RE: Pietenpol-List: Spring Gear Jack, The required length of the slot is dependant on the amount of travel you will want/need. The amount of travel you will actually get is dependant on the weight of the plane, how hard you "land" and the specifics of the actual springs you use. That's a lot of variables! The example provided in Tony's book is likely for a specific plane (although it could easily apply to many of a similar size/configuration). It may, or may not apply to the Pietenpol. To make life easier, since we're talking about Pietenpols, why don't we refer to a couple of drawings that apply specifically to Pietenpols. The first is a drawing that came from the old BPA Newsletters, and was drawn in 1984 by Frank Pavliga Sr, I believe. In this drawing, the slot is 2 3/4" long. http://www.mykitplane.com/Planes/photoDisplay.cfm?PhotoName=lndg_gear_s p ring.jpg&PhotoID 09 The second drawing is a little more recent (2005), and was done by Hans van der Voort, as built on his award-winning Piet. In this arrangement, the slot is 2 1/2" long. http://www.mykitplane.com/Planes/filesList2.cfm?AlbumID=75 So it looks like the slot probably should be longer for use on the Piet. I think either of these arrangements will work well for the Piet. At least I do not recall ever reading that anyone built to either design and was not satisfied with the performance. Personally, I'm going with the wooden Jenny-style gear, so I'll never know first hand how they perform, but if I was building the split gear, I'd go with springs rather than bungees. Bill C. ________________________________ From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of jack@textors.com Sent: Wednesday, October 07, 2009 2:30 PM Subject: Pietenpol-List: Spring Gear All, Can you assist with a question on spring gear? The attached photo is from Tony's book. He states that the slot is 1 3/4" long. Does that sound like enough travel? Thanks, Jack www.textors.com href="http://www.matronics.com/Navigator?Pietenpol-List">http://www.mat r onics.com/Navigator?Pietenpol-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c 270.14.4/2417 - Release Date: 10/06/09 06:50:00 ________________________________ Message 18 ____________________________________ Time: 10:19:01 AM PST US From: "Lagowski Morrow" Subject: Re: Pietenpol-List: control cable exit holes I used pinked edge leather patches glued to the finish painted fabric with Polytak, which is the glue used with the Poly fiber system. My patches have survived for~42 hours with no sign of coming loose--Jim Lagowski ----- Original Message ----- From: shad bell To: pietenpol-list@matronics.com Sent: Thursday, October 08, 2009 12:12 PM Subject: RE: Pietenpol-List: control cable exit holes Anothe methood is to sew the leather to a piece of fabric, then glue the fabric to the fabric, then it wont peel off with age due to drying out or shrinkage of the leather. Just make a teardrop shaped leather exit patch, and then make a fabric patch that is 1 inch bigger all the way around the perimeter, then stich the leather to the fabric, and then glue the fabric/leather patch to the airplane. I think this might stick better because fabric glues are best suited to glue dacron to dacron. I will admit though most airplanes I see do have the leather patches just glued on. Some I see are peeling off some don't. I have also seen a trick where people will laminate a piece of 1/16 plywood between the backside of the fabric, and cover the ply to make a fabric-ply-fabric sandwich for cable exits. This seems to give the cleanest instalation, but I think the leather route looks the most time period correct for a piet. Probably 100 other methoods of doing it, Shad ________________________________ Message 19 ____________________________________ Time: 10:19:24 AM PST US Subject: Re: Pietenpol-List: tailwheel springs From: Ryan Mueller I believe that reason would be 'compromise'....between size, structure, performance, etc. I would bet that with most two seat certified aircraft you can load them with full fuel, passengers, and baggage or come a few pounds within doing so.....if you load them with the standard 170lb passengers. If you choose to load non-standard size passengers then you will have to compromise and reduce payload elsewhere, but that's not the airplane's fault. ;) I'm happy that the Sonex guys can use tailwheel setups with no springs, and if we were building a Sonex we would do that too. Unfortunately we are building an entirely different airplane, and the 80 some odd years of empirical data thus far indicates that springs are a good idea with this design. As such we will use them, but we will be interested to see how your experiment of a 'spring-less' tailwheel setup on a Piet eventually turns out. Good luck! Ryan do not archive On Thu, Oct 8, 2009 at 8:12 AM, Doug Dever wrote: > Gene, > > There must be a good reason you can't put full fuel, pax and baggage in > most cert. aircraft either. I can't figure it out. > > Doug Dever > In beautiful Stow Ohio > > > ------------------------------ > From: generambo@msn.com > To: pietenpol-list@matronics.com > Subject: Re: Pietenpol-List: tailwheel springs > Date: Thu, 8 Oct 2009 08:11:22 -0400 > > I think the springs also help eliminate shimmying, although logically you > would think it would increase it. Just think, ALL Cubs, Champs, > Taylorcrafts, Cessnas, etc, etc, etc use them. There MUST be a good reason. > > Gene > > ----- Original Message ----- > *From:* Douwe Blumberg > *To:* pietenpolgroup > *Sent:* Wednesday, October 07, 2009 8:24 AM > *Subject:* Pietenpol-List: tailwheel springs > > douweblumberg@earthlink.net> > > One more thing... > > There was some talk (writing??) awhile back about not using tailwheel > springs and it set me to thinking. What would happen if one didn't use > springs, just straight cables? > > Obviously, bumps and jerks will be transmitted directly to the rudder bar, > which is about the only downside I can see. Seems like you'd get rid of > some potential uncontrolled movement back there without springs, and you'd > save a few ounces. > > In you flyer's experiences, how bad can the bumps and jerks be from the > tailwheel, and what do you think of this idea? > > Thanks > > Douwe, > > ________________________________ Message 20 ____________________________________ Time: 11:19:02 AM PST US Subject: Re: Pietenpol-List: Spring Gear From: steven sadler For a Lamina H-56 spring (a common die spring for small aircraft use), the manufacturer's numbers show a maximum compression of 1.65". For that spring, there isn't any point in making the slot much longer than 1 3/4" because the spring will be fully compressed already. I am thinking that for any spring, you want the slot just slightly longer than the spring full compression distance. Steve in Winnipeg On Wed, Oct 7, 2009 at 1:29 PM, wrote: > All, > Can you assist with a question on spring gear? The attached photo is from > Tony's book. He states that the slot is 1 3/4" long. Does that sound like > enough travel? > Thanks, > Jack > www.textors.com > ________________________________ Message 21 ____________________________________ Time: 12:11:21 PM PST US From: "Perry Rhoads" Subject: Pietenpol-List: Vi Kaplar's Pietenpols List Members, Attached is a picture of Mr. Vitalis Kapler's newly completed Pietenpol. It's very well done with a Ford A engine. Vi did everything possible to keep the weight down. I think he said it weighted 610#. He hasn't flown it yet, but I'm sure he's trying to get it airworthy before the Minnesota winter sets in. Also, Mr. Kapler has sold me his Pietenpol N12939, that he has owned for 23 years. I'm proud to be the next caretaker of this fine old airplane. Perry Rhoads Carlinville,IL. N12939 ________________________________ Message 22 ____________________________________ Time: 12:11:34 PM PST US Subject: Re: Pietenpol-List: Spring Gear From: hvandervoo@aol.com I have great succes with my setup. see:http://www.mykitplane.com/Planes/filesList2.cfm?AlbumID=75 Spring is from Aircraft Spruce. BR Hans -----Original Message----- From: steven sadler Sent: Thu, Oct 8, 2009 1:18 pm Subject: Re: Pietenpol-List: Spring Gear For a Lamina H-56 spring (a common die spring for small aircraft use), the manufacturer's numbers show a maximum compression of 1.65". For that spring, there isn't any point in making the slot much longer than 1 3/4" because the spring will be fully compressed already. ? I am thinking that for any spring, you want the slot just slightly longer than the spring full compression distance. ? Steve in Winnipeg On Wed, Oct 7, 2009 at 1:29 PM, wrote: All, Can you assist with a question on spring gear?? The attached photo is from Tony's book.? He states that the slot is 1 3/4" long.? Does that sound like enough travel? Thanks, Jack www.textors.com ________________________________ Message 23 ____________________________________ Time: 12:39:07 PM PST US Subject: RE: Pietenpol-List: Spring Gear From: "Bill Church" I've attached a JPG image of the Lamina catalog page that shows the H56 spring data, highlighted. The maximum recommended operating deflection is 1.68", but the Max compressed length is 3.82", which means that the spring can actually compress 6 - 3.82 = 2.18". This is not recommended, but is possible. The H-56 Lamina is the spring called for in the Frank Pavliga drawing: http://www.mykitplane.com/Planes/photoDisplay.cfm?PhotoName=lndg_gear_s p ring.jpg&PhotoID 09 In that drawing, the arrangement uses a 1/4" diameter cross-bolt. There is a note that says the slot should be 1/4" x length to allow for full compression of spring (2 3/4" for H-56). Based on the data from the catalog, full compression of the spring will take 2.18" of travel. Add the diameter of the cross bolt (0.25") for the minimum slot length: 2.18 + 0.25 = 2.43". So, a 2 1/2" slot would suffice. If a slot with length of only 1 3/4" is used with the H-56 spring, and a 1/4" diameter cross-bolt, the spring will only be able to compress 1 3/4" - 1/4" = 1 1/2". Based on the catalog data, the H-56 spring takes 58.4 pounds per 1/10" of deflection, so the landing gear will reach the end of the slot at a loading of 876 pounds. That might not be enough travel. But in general, the slot length should be just slightly longer than the sum of the spring full compression distance plus the diameter of the cross-bolt (or pin). Bill C. ________________________________ From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of steven sadler Sent: Thursday, October 08, 2009 2:18 PM Subject: Re: Pietenpol-List: Spring Gear For a Lamina H-56 spring (a common die spring for small aircraft use), the manufacturer's numbers show a maximum compression of 1.65". For that spring, there isn't any point in making the slot much longer than 1 3/4" because the spring will be fully compressed already. I am thinking that for any spring, you want the slot just slightly longer than the spring full compression distance. Steve in Winnipeg ________________________________ Message 24 ____________________________________ Time: 12:52:13 PM PST US From: Jim Markle Subject: Re: Pietenpol-List: Vi Kaplar's Pietenpols WOW! That thing is beautiful! Can't wait to see it at Brodhead. Any idea what hinges he used? :-) Sure is a beauty (both actually!)..... ________________________________ Message 25 ____________________________________ Time: 01:08:49 PM PST US From: "KMHeide, BA, CPO, FAAOP" Subject: Re: Pietenpol-List: bell crank spring for trim control -Members: - I have a unique set-up in mind for my trim system.-Please interject your comments!- - I purchase a casement window small size window-crank with a butterfly han dle-for use a my trim system in the cockpit. I can turn the crank either way and get the necessary stick pressure for trim of the horizontal stabili zer. I will post my photos and sketches when-I take on this task over the weekend. - The question I have is this: What size and strength and stretch of spring i s needed for attachment to the bell crank for tension? - My system was to use two springs attached to the rear of the bell crank one high and one low. One spring will attach to a fixed support glued in place . The other spring will be attached to a cable which will run through a pul ley and back to the cockpit. As the crank turns for adjustment, the cable w ill make stick pressure while the other spring creates return stick pressur e. Making sense? - Flame me or scratch your head..... I believe this would make for a much eas ier trim system rather then a trim tab attached to my stabilizer. - Comments and jesters welcome. - KMHeide -=0A=0A=0A ________________________________ Message 26 ____________________________________ Time: 01:22:06 PM PST US Subject: Pietenpol-List: Re: toasting-- Jimmy Doolittle style From: "Baldeagle" There are now only 9 left I think, and the AF Museum is planning to re-pave the old runway next to the museum so they can land B-25s there next April for the Raider Reunion. They may open the Cognac then since many of the survivors are in poor health and they're worried that if they wait till the last two they won't be able to do the toast. - Read this topic online here: http://forums.matronics.com/viewtopic.php?p=267141#267141 ________________________________ Message 27 ____________________________________ Time: 01:22:06 PM PST US From: "KMHeide, BA, CPO, FAAOP" Subject: Pietenpol-List: RE: Front cowling for the pietenpol Members of the list: I am taking orders for those who are seeking a fiberglass two piece cowling as seen on the Original Pietenpol. I have duplicated the mold of that cowl ing (Thanks Dan) and will be creating more of them within the next few week s. Costs are around $250.00 plus shipping (plus the box). Please send me a message so I know the number I need to make! =C2- =C2- Here as the dimensions of the cowlings finished. =C2- The smaller cowling (bottom) is 7=9D deep X 20=9D long X 26 =9D wide at the widest point. The larger cowling (Top) is 13=9D de ep X 22=9D long X 29=9D wide. =C2- KMHeide =C2-=0A=0A=0A ________________________________ Message 28 ____________________________________ Time: 02:38:41 PM PST US From: Dan Yocum Subject: Re: Pietenpol-List: control cable exit holes Hm. Do you guys think that I should peel off the top 1 or 2 layers of paint to get down to the Poly-Spray? The top layer (Sherwin Williams) peels off pretty readily with a good sticky tape, just like Jeff B. said it would. The original Dulux paint seems to be pretty well adhered to the fabric - at least, I haven't peeled any off, yet. Thanks, Dan Lagowski Morrow wrote: > I used pinked edge leather patches glued to the finish painted fabric > with Polytak, which is the glue used with the Poly fiber system. My > patches have survived for~42 hours with no sign of coming loose--Jim > Lagowski > > ----- Original Message ----- > *From:* shad bell > *To:* pietenpol-list@matronics.com > > *Sent:* Thursday, October 08, 2009 12:12 PM > *Subject:* RE: Pietenpol-List: control cable exit holes > > Anothe methood is to sew the leather to a piece of fabric, then glue > the fabric to the fabric, then it wont peel off with age due to > drying out or shrinkage of the leather. Just make a teardrop shaped > leather exit patch, and then make a fabric patch that is 1 inch > bigger all the way around the perimeter, then stich the leather to > the fabric, and then glue the fabric/leather patch to the airplane. > I think this might stick better because fabric glues are best suited > to glue dacron to dacron. I will admit though most airplanes I see > do have the leather patches just glued on. Some I see are peeling > off some don't. I have also seen a trick where people will laminate > a piece of 1/16 plywood between the backside of the fabric, and > cover the ply to make a fabric-ply-fabric sandwich for cable exits. > This seems to give the cleanest instalation, but I think the leather > route looks the most time period correct for a piet. > > Probably 100 other methoods of doing it, > Shad > > > * > > 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 > * > > * > > > * -- Dan Yocum Fermilab 630.840.6509 yocum@fnal.gov, http://fermigrid.fnal.gov Fermilab. Just zeros and ones. ________________________________ Message 29 ____________________________________ Time: 02:48:26 PM PST US From: Oscar Zuniga Subject: Pietenpol-List: Vi Kapler's Piets I'm going to have to have a word with Mr. Kapler about not using so much dihedral in the wings! ;o) Both those Piets look to have as close to zero dihedral as I've ever seen... in fact, the new one looks to have ANhedral. They both look like one-piece wings, too. Looks like he has routed the tailwheel steering cables out the bottom of the tail section rather than the sides. Not sure I had ever seen that before. Oscar Zuniga Air Camper NX41CC San Antonio, TX mailto: taildrags@hotmail.com website at http://www.flysquirrel.net ________________________________ Message 30 ____________________________________ Time: 03:37:16 PM PST US Subject: Pietenpol-List: Cable exits From: helspersew@aol.com Dan Yocum, These photos are from Larry William's plane. This is what I did also, but I will mask-off the leather from being painted. If you strip off your paint I bet you could do this too. Dan Helsper Poplar Grove, IL. ________________________________ Message 31 ____________________________________ Time: 04:54:55 PM PST US From: "Jack" Subject: RE: RE: Pietenpol-List: Spring Gear Once again, thanks Bill, Hans, Steve and others, your input is invaluable! What a great resource! Jack www.textors.com I've attached a JPG image of the Lamina catalog page that shows the H56 spring data, highlighted. The maximum recommended operating deflection is 1.68", but the Max compressed length is 3.82", which means that the spring can actually compress 6 - 3.82 = 2.18". This is not recommended, but is possible. The H-56 Lamina is the spring called for in the Frank Pavliga drawing: http://www.mykitplane.com/Planes/photoDisplay.cfm?PhotoName=lndg_gear_spring .jpg &PhotoID 09 In that drawing, the arrangement uses a 1/4" diameter cross-bolt. There is a note that says the slot should be 1/4" x length to allow for full compression of spring (2 3/4" for H-56). Based on the data from the catalog, full compression of the spring will take 2.18" of travel. Add the diameter of the cross bolt (0.25") for the minimum slot length: 2.18 + 0.25 = 2.43". So, a 2 1/2" slot would suffice. If a slot with length of only 1 3/4" is used with the H-56 spring, and a 1/4" diameter cross-bolt, the spring will only be able to compress 1 3/4" - 1/4" = 1 1/2". Based on the catalog data, the H-56 spring takes 58.4 pounds per 1/10" of deflection, so the landing gear will reach the end of the slot at a loading of 876 pounds. That might not be enough travel. But in general, the slot length should be just slightly longer than the sum of the spring full compression distance plus the diameter of the cross-bolt (or pin). Bill C. _____ From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of steven sadler Sent: Thursday, October 08, 2009 2:18 PM Subject: Re: Pietenpol-List: Spring Gear For a Lamina H-56 spring (a common die spring for small aircraft use), the manufacturer's numbers show a maximum compression of 1.65". For that spring, there isn't any point in making the slot much longer than 1 3/4" because the spring will be fully compressed already. I am thinking that for any spring, you want the slot just slightly longer than the spring full compression distance. Steve in Winnipeg Checked by AVG - www.avg.com 18:33:00 ________________________________ Message 32 ____________________________________ Time: 05:08:29 PM PST US From: "Jack" Subject: RE: RE: Pietenpol-List: Spring Gear Thanks Jerry, but don't dig too deep... Jack Textor 29 SW 58th Drive Des Moines, IA 50312 www.textors.com -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of JERRY GROGAN Sent: Thursday, October 08, 2009 7:27 AM Subject: Re: RE: Pietenpol-List: Spring Gear Jack I think I have a set of the spring gear here at the shop, done you could look at. I would need to dig a little but we have one made for the Smith Miniplane. And it can only traval as much as the slot is long. But that is all the spring can traval anyway. Jerry Sky Classic Aircraft ----- Original Message ----- From: "Jack" Sent: Thursday, October 08, 2009 6:14 AM Subject: RE: RE: Pietenpol-List: Spring Gear > > Thanks so much to all, valuable input! > Jack > www.textors.com > > > Very close, Jeff. > You would need to add the diameter of the cross bolt that holds the > spring. > Since the cross bolt is already in the slot, it will need to be able to > move > the full compression of the spring. > That will give the MINIMUM length the slot should be. > > Bill C. > > -----Original Message----- > From: owner-pietenpol-list-server@matronics.com on behalf of Jeff > Boatright > Sent: Wed 07/10/2009 9:24 PM > To: pietenpol-list@matronics.com > Subject: Re: Pietenpol-List: Spring Gear > > > I may be off on this, probably am, but it seems to me that the space > between the spring spirals add up to the entire distance that the > spring can compress. If so, then that's how long the slot needs to > be, right? > >> >> >>Jack I made my shock struts per Bill Reweys drawing for spring >>struts. The slot is 2.75" long on my struts. I have not flown them >>yet but with 6" springs this seems like a better slot length. Get >>the packet of Pietenpol tips and hints direct from Bill. >>Jim B. >> >>Jim Boyer >>Santa Rosa, CA >>Pietenpol builder with Corvair >> >>Oct 7, 2009 11:44:15 AM, pietenpol-list@matronics.com wrote: >> >>All, >>Can you assist with a question on spring gear? The attached photo >>is from Tony's book. He states that the slot is 1 3/4" long. Does >>that sound like enough travel? >>Thanks, >>Jack >>www.textors.com > > > Checked by AVG - www.avg.com > 05:18:00 > > > Checked by AVG - www.avg.com 18:33:00 ________________________________ Message 33 ____________________________________ Time: 05:22:23 PM PST US Subject: Re: Pietenpol-List: Spring Gear From: steven sadler Bill, Thanks for the information. This is an important subject for me as I intend to finish putting the springs on my landing gear this weekend. Can you take a look at my information below and see if I have missed something? I think we are looking at different springs. The Lamina H-56 and H-56L springs are shown in different Lamina catalogs and have slightly different information. The H-56 springs show a maximum allowable deflection of 1.80" (not the 1.65" I stated earlier - I misread the number) at 1.8 * 10 * 58.4 lbs/0.1 inch = 1051 lbs at full deflection. It is interesting that the H-56L spring shows a fully compressed length but the H-56 doesn't. The H-56L appears to have a bit more travel and might actually be a better choice. My arithmetic shows, for a 2.18" travel @ 58.4" per 1/10" travel: 2.18 * 10 * 58.4 = 1273 lbs at full compression. With two springs, the total available force before bottoming out will be 2500 lbs+. Either way, it looks like a hard landing in a 1200 lb airplane will probably bottom out the springs. Steve in Winnipeg On Thu, Oct 8, 2009 at 2:37 PM, Bill Church wrote: > I've attached a JPG image of the Lamina catalog page that shows the H56 > spring data, highlighted. > The maximum recommended operating deflection is 1.68", but the Max > compressed length is 3.82", which means that the spring can actually > compress 6 - 3.82 = 2.18". This is not recommended, but is possible. > > The H-56 Lamina is the spring called for in the Frank Pavliga drawing: > > > http://www.mykitplane.com/Planes/photoDisplay.cfm?PhotoName=lndg_gear_spring.jpg&PhotoID 09 > > In that drawing, the arrangement uses a 1/4" diameter cross-bolt. > There is a note that says the slot should be *1/4" x length to allow for > full compression of spring (2 3/4" for H-56).* > Based on the data from the catalog, full compression of the spring will > take 2.18" of travel. Add the diameter of the cross bolt (0.25") for the > minimum slot length: 2.18 + 0.25 = 2.43". So, a 2 1/2" slot would suffice. > > If a slot with length of only 1 3/4" is used with the H-56 spring, and a > 1/4" diameter cross-bolt, the spring will only be able to compress 1 3/4" - > 1/4" = 1 1/2". Based on the catalog data, the H-56 spring takes 58.4 pounds > per 1/10" of deflection, so the landing gear will reach the end of the slot > at a loading of 876 pounds. That might not be enough travel. > > But in general, the slot length should be just slightly longer than the sum > of the spring full compression distance plus the diameter of the cross-bolt > (or pin). > > Bill C. > > ------------------------------ > *From:* owner-pietenpol-list-server@matronics.com [mailto: > owner-pietenpol-list-server@matronics.com] *On Behalf Of *steven sadler > *Sent:* Thursday, October 08, 2009 2:18 PM > *To:* pietenpol-list@matronics.com > *Subject:* Re: Pietenpol-List: Spring Gear > > For a Lamina H-56 spring (a common die spring for small aircraft use), > the manufacturer's numbers show a maximum compression of 1.65". For that > spring, there isn't any point in making the slot much longer than 1 3/4" > because the spring will be fully compressed already. > > I am thinking that for any spring, you want the slot just slightly longer > than the spring full compression distance. > > Steve in Winnipeg > ________________________________ Message 34 ____________________________________ Time: 06:51:33 PM PST US From: "Cuy, Michael D. (GRC-RXD0)[ASRC Aerospace Corporation]" Subject: Pietenpol-List: Javier is back ! Very good to see you back on the list Javier ! You have the attention of your neighbors now when you run you engine ? Very good ! They probably wonder why an accomplished pilot like yourself who flies jets for the government would ever want to build the lowly Pietenpol. I don't know how many guys I've heard over the years who flew heavy iron, fighter jets, airliners, and warbirds say that they were building "A Pietenpol Air Camper". There is something about them. I can't say I have any more of that gracious gift you gave me when you visited Brodhead a few years ago but it certainly gave me reason to toast a classy Pietenpol builder from Mexico ! Keep us posted on your progress and send photos when you can ! Mike C. Ohio ________________________________ Message 35 ____________________________________ Time: 06:54:17 PM PST US From: Oscar Zuniga Subject: Pietenpol-List: Spring Gear Regarding the spring and the slot and the travel: don't discount the effect of pneumatic tires. If you are not using motorcycle tires, the pneumatic effect of donut tires does a lot to dampen the impact of landing even without the springs. It's hard to quantify all of those effects in combination, particularly if you operate off of grass and turf, but there are airplanes that have no springs, bungees, or other damping in their landing gear at all... just the tires. For those who use skinny motorcycle tires, there is still pneumatic damping and cushion, but it's not as much of the "Pillsbury Doughboy" or "Michelin Man" effect that donut tires have, of course. You can over-analyze this thing, guys! I say, go with the 2-1/2" or 2-3/4" long slots. If the springs bottom out before the bolts reach the ends of the slots, the effect is the same but the springs are probably better able to take a hard stop at the end of their travel than the slots and bolts are able to do the same. From there, the tires will do their part to soften the 'thump' of a solid landing. And the best advice of all is to operate your Piet off of grass as much as possible. It is absolutely heavenly, and makes all of your landings look perfect. I love the "ssss" of an early morning landing on damp, green grass! Oscar Zuniga Air Camper NX41CC San Antonio, TX mailto: taildrags@hotmail.com website at http://www.flysquirrel.net ________________________________ Message 36 ____________________________________ Time: 07:21:21 PM PST US Subject: Re: Pietenpol-List: hickory wood From: Robert Ray I don't want no skinny cabanes no sir, how ever I like women with skinny legs! On Thu, Oct 8, 2009 at 9:34 AM, Bill Church wrote: > eng@canadianrogers.com> > > > For the loads imposed on the cabane struts (only about 50 pounds or so, > each), ALMOST any type of wood would likely be sufficient. I wrote the > word "almost" in caps to avoid having anyone following up with wiseguy > suggestions like using spalted burls for the cabanes (well, that's what > I would probably do anyway). > Cabane struts made of Spruce can handle the loads - provided an adequate > cross-section is used, and the connection details are also properly > thought out. > Actually, the connection details are likely more important than the > species of wood used. > Substituting wood cabanes for the streamline steel shown in the plans is > a structural change, so of course, anyone proposing making a change like > this should either do the calculations themselves (if they are > qualified), or have them done by someone who is qualified. Don't mess > with it if you don't know what you're doing. > > I don't have the info at my fingertips, but as I recall, if made of > 4130, the cabanes could be as small as (maybe) 1/2" diameter tube (?) to > carry the loads imposed on them. But they would look stupid. Visually > they would not appear to be correct. > > Bill C. > > ________________________________ Message 37 ____________________________________ Time: 07:21:37 PM PST US From: "Clif Dawson" Subject: Re: Pietenpol-List: tailwheel springs Just like in racing. If you want to be succesful, copy the leaders. Clif I think the springs also help eliminate shimmying, although logically you would think it would increase it. Just think, ALL Cubs, Champs, Taylorcrafts, Cessnas, etc, etc, etc use them. There MUST be a good reason. Gene ________________________________ Message 38 ____________________________________ Time: 07:41:59 PM PST US From: "Clif Dawson" Subject: Re: Pietenpol-List: hickory wood There's nothing wrong with spruce or hemlock. Ash, hickory etc. are heavy with no real advantage. The reason for ash use in handles is shock resistance and, if properly made, shock mitigation to one's hands and arms. Both of which are across the grain. Oak and fir are not good choices as the have less resistance to tearout parallel to the grain. Go to this message to see analysis- message #40283; http://www.matronics.com/searching/getmsg_script.cgi?INDEX=57771674?KEYS=cabane?LISTNAME=Pietenpol?HITNUMBER=316?SERIAL=19290813641X?SHOWBUTTONS=YES Clif > > Jorge; I think hickory wood is what is commonly used > foraxe handles. You can also use ash if you are making > cabane struts from wood. You could probably also > use oak. > > Oscar Zuniga ________________________________ Message 39 ____________________________________ Time: 07:42:38 PM PST US From: "Clif Dawson" Subject: Re: Pietenpol-List: hickory wood But then you COULD surround them with burl. :-) Clif Seneca: "There is no great genius without a tincture of madness." > I don't have the info at my fingertips, but as I recall, if made of > 4130, the cabanes could be as small as (maybe) 1/2" diameter tube But they > would look stupid. > > Bill C. ________________________________ Message 40 ____________________________________ Time: 08:04:47 PM PST US Subject: Re: Pietenpol-List: Spring Gear From: Ryan Mueller Steve, You may want to check with a supplier or distributor of Lamina products, but I think you may be looking at an outdated catalog. I believe Bill pulled that page from the most recent catalog, dated May 20, 2008, available from the Anchor Lamina website: http://www.anchorlamina.com/pdf.d/DieMaxDieSprings.pdf The H56L spring listed is the only spring shown in any of the current catalogs on the Anchor Lamina site (that I can find) that is almost identical to the H-56 listings that I can find in the older catalogs from third party suppliers websites. Two main differences: they have appended an 'L' to the part name, and the wire dimensions changed from .225" x .350" for the H56 to .245" x .328" for the H56L. The maximum operating deflection of 1.80" for the H56 that you give is at 30% of the free length of the spring. The H56L catalog listing does not give a value for maximum operating deflection at 30% of the free length; they now consider 28% of the free length to be the maximum operating deflection, which for the H56L is 1.68". If you compressed the H56L to 30% of the free length would the deflection increase 0.12"? I don't know, but I think it's a moot point because it's pretty close, and because both catalogs make note that the 28/30% max deflection is for design and informational purposes only; you wouldn't want to be approaching those values in practical application. As far as the deflection values at 15% and 20% of free length, they are exactly the same between the H56 and H56L. In a nutshell, it would appear to me that the H56 spring became (or has been superseded by) the H56L, but thankfully they have almost identical operating properties according to the catalog. Again, give Anchor Lamina or a distributor a call to be sure. HTH, Ryan On Thu, Oct 8, 2009 at 7:19 PM, steven sadler wrote: > Bill, > > Thanks for the information. This is an important subject for me as I intend > to finish putting the springs on my landing gear this weekend. Can you take > a look at my information below and see if I have missed something? > > I think we are looking at different springs. The Lamina H-56 and H-56L > springs are shown in different Lamina catalogs and have slightly different > information. The H-56 springs show a maximum allowable deflection of 1.80" > (not the 1.65" I stated earlier - I misread the number) at 1.8 * 10 * 58.4 > lbs/0.1 inch = 1051 lbs at full deflection. It is interesting that the > H-56L spring shows a fully compressed length but the H-56 doesn't. The H-56L > appears to have a bit more travel and might actually be a better choice. > > My arithmetic shows, for a 2.18" travel @ 58.4" per 1/10" travel: 2.18 * > 10 * 58.4 = 1273 lbs at full compression. With two springs, the total > available force before bottoming out will be 2500 lbs+. > > Either way, it looks like a hard landing in a 1200 lb airplane will > probably bottom out the springs. > > Steve in Winnipeg > > On Thu, Oct 8, 2009 at 2:37 PM, Bill Church wrote: > >> I've attached a JPG image of the Lamina catalog page that shows the H56 >> spring data, highlighted. >> The maximum recommended operating deflection is 1.68", but the Max >> compressed length is 3.82", which means that the spring can actually >> compress 6 - 3.82 = 2.18". This is not recommended, but is possible. >> >> The H-56 Lamina is the spring called for in the Frank Pavliga drawing: >> >> >> http://www.mykitplane.com/Planes/photoDisplay.cfm?PhotoName=lndg_gear_spring.jpg&PhotoID 09 >> >> In that drawing, the arrangement uses a 1/4" diameter cross-bolt. >> There is a note that says the slot should be *1/4" x length to allow for >> full compression of spring (2 3/4" for H-56).* >> Based on the data from the catalog, full compression of the spring will >> take 2.18" of travel. Add the diameter of the cross bolt (0.25") for the >> minimum slot length: 2.18 + 0.25 = 2.43". So, a 2 1/2" slot would suffice. >> >> If a slot with length of only 1 3/4" is used with the H-56 spring, and a >> 1/4" diameter cross-bolt, the spring will only be able to compress 1 3/4" - >> 1/4" = 1 1/2". Based on the catalog data, the H-56 spring takes 58.4 pounds >> per 1/10" of deflection, so the landing gear will reach the end of the slot >> at a loading of 876 pounds. That might not be enough travel. >> >> But in general, the slot length should be just slightly longer than the >> sum of the spring full compression distance plus the diameter of the >> cross-bolt (or pin). >> >> Bill C. >> >> ------------------------------ >> *From:* owner-pietenpol-list-server@matronics.com [mailto: >> owner-pietenpol-list-server@matronics.com] *On Behalf Of *steven sadler >> *Sent:* Thursday, October 08, 2009 2:18 PM >> *To:* pietenpol-list@matronics.com >> *Subject:* Re: Pietenpol-List: Spring Gear >> >> For a Lamina H-56 spring (a common die spring for small aircraft use), >> the manufacturer's numbers show a maximum compression of 1.65". For that >> spring, there isn't any point in making the slot much longer than 1 3/4" >> because the spring will be fully compressed already. >> >> I am thinking that for any spring, you want the slot just slightly longer >> than the spring full compression distance. >> >> Steve in Winnipeg >> > > * > > > * > > ________________________________ Message 41 ____________________________________ Time: 08:04:48 PM PST US From: shad bell Subject: Re: Pietenpol-List: RE: Front cowling for the pietenpol Not to steel any buisness, but Dad has an original Bernard style corvair co wling he bought and never used, and is looking to sell it.- It is in perf ect shape, and still in the box I believe.- If anyone is interested let m e know, and I'll pass any info on to him.- He doesnt want too much for it , just to recoup some of the cost he bought it for. - Shad=0A=0A=0A ________________________________ Message 42 ____________________________________ Time: 08:11:52 PM PST US Subject: Re: Pietenpol-List: hickory wood From: Ryan Mueller Russell, There is a feature on the Pietenpol list called the 'do not archive' tag. I'm sure you have noticed some of list subscribers use it from time to time. It allows your message to go out to the list and be seen and read by all, but it does not store a copy of the message in the archive for posterity. You use this for messages that have no need to be stored in the archives, usually because they contain no useful information for people that go searching in the archives for building hints, data, methods and practices, etc. These may be messages welcoming someone to the list, giving congratulations for achievements; all sorts of things. I can, shall we say, guaran-damn-teed you that there is no one - absolutely no one - who will be searching for information in the archives about wood cabane struts that will gain anything from reading that you don't want no skinny cabanes, but you like women with skinny legs. Not a soul. So if such a message must be sent out, it would be the polite thing to do to just put 'do not archive' at the end of the message, to help out those folks down the road who are looking for information in the always helpful Pietenpol list archive. Just a suggestion. Thanks! Ryan On Thu, Oct 8, 2009 at 9:16 PM, Robert Ray wrote: > I don't want no skinny cabanes no sir, how ever I like women with skinny > legs! > > On Thu, Oct 8, 2009 at 9:34 AM, Bill Church wrote: > >> eng@canadianrogers.com> >> >> >> For the loads imposed on the cabane struts (only about 50 pounds or so, >> each), ALMOST any type of wood would likely be sufficient. I wrote the >> word "almost" in caps to avoid having anyone following up with wiseguy >> suggestions like using spalted burls for the cabanes (well, that's what >> I would probably do anyway). >> Cabane struts made of Spruce can handle the loads - provided an adequate >> cross-section is used, and the connection details are also properly >> thought out. >> Actually, the connection details are likely more important than the >> species of wood used. >> Substituting wood cabanes for the streamline steel shown in the plans is >> a structural change, so of course, anyone proposing making a change like >> this should either do the calculations themselves (if they are >> qualified), or have them done by someone who is qualified. Don't mess >> with it if you don't know what you're doing. >> >> I don't have the info at my fingertips, but as I recall, if made of >> 4130, the cabanes could be as small as (maybe) 1/2" diameter tube (?) to >> carry the loads imposed on them. But they would look stupid. Visually >> they would not appear to be correct. >> >> Bill C. >> s List Un/Subscription, >> www.matronics.com/Navigator?Pietenpol-List" target="_blank"> >> http://www.matronics.com/Navigator?Pietenpol-List >> ronics.com/" target="_blank">http://forums.matronics.com >> Matt Dralle, List Admin. >> ==== >> >> >> >> > * > > * > > ________________________________ Message 43 ____________________________________ Time: 08:18:36 PM PST US From: Oscar Zuniga Subject: Pietenpol-List: hickory wood I'm not sure where this thread is going, but more than 40 years ago I caught the scent of a skinny girl pushing her skateboard down a concrete ramp down in Laredo, Texas and that was all it took for us to start a relationship that has taken us through a whole heck of a lot of things, and situations, and years. Her suntanned legs still look as good as fine strong wood to me, and when she talks to me about seeing some long sandy beach in northern Africa or out in Australia, she sees a beach and a setting sun and waves rolling in and a fire after dark that we make with driftwood that months and months at sea have brought to the shore- and I see a smooth ribbon of sand that I can put my Pietenpol down on, with just a gentle rumble of the tires on the sand in the ripples that the waves have made. She sees the reflection of the setting sun on miles of endless waves, coming in from the distant Atlantic ocean or the deep blue Mediterranean, with camels crossing the endless desert, while I picture a smooth enough place between the tide-pools to put the Air Camper down on the sand and not bounce the landing. We both appreciate the view, but each of us sees it a bit differently. When the airplane rolls to a stop, we both see it the same. I hear the tick-tick-tick of the engine cooling off as I start the fire to make dinner, she sees it as the hiss of the waves rolling in from the sea. We pour some wine, we eat a meal with stars above, and both of our dreams blend together in perfect harmony of suntanned legs, fabric covered wings, the stars, a meal, wine, and endless time. Oscar Zuniga Air Camper NX41CC San Antonio, TX mailto: taildrags@hotmail.com website at http://www.flysquirrel.net do not archive ________________________________ Message 44 ____________________________________ Time: 08:29:43 PM PST US Subject: Re: Pietenpol-List: hickory wood From: Robert Ray I'll have to WOW this! On Thu, Oct 8, 2009 at 11:15 PM, Oscar Zuniga wrote: > > > I'm not sure where this thread is going, but more than > 40 years ago I caught the scent of a skinny girl pushing > her skateboard down a concrete ramp down in Laredo, Texas > and that was all it took for us to start a relationship > that has taken us through a whole heck of a lot of things, > and situations, and years. Her suntanned legs still look > as good as fine strong wood to me, and when she talks to > me about seeing some long sandy beach in northern Africa or > out in Australia, she sees a beach and a setting sun and > waves rolling in and a fire after dark that we make with > driftwood that months and months at sea have brought to > the shore- and I see a smooth ribbon of sand that I can > put my Pietenpol down on, with just a gentle rumble of > the tires on the sand in the ripples that the waves have > made. > > She sees the reflection of the setting sun on miles of > endless waves, coming in from the distant Atlantic ocean > or the deep blue Mediterranean, with camels crossing the > endless desert, while I picture a smooth enough place > between the tide-pools to put the Air Camper down on the > sand and not bounce the landing. We both appreciate the > view, but each of us sees it a bit differently. When the > airplane rolls to a stop, we both see it the same. I > hear the tick-tick-tick of the engine cooling off as I > start the fire to make dinner, she sees it as the hiss of > the waves rolling in from the sea. We pour some wine, we > eat a meal with stars above, and both of our dreams blend > together in perfect harmony of suntanned legs, fabric > covered wings, the stars, a meal, wine, and endless time. > > Oscar Zuniga > Air Camper NX41CC > San Antonio, TX > mailto: taildrags@hotmail.com > website at http://www.flysquirrel.net > > do not archive > > ________________________________ Message 45 ____________________________________ Time: 09:12:25 PM PST US From: "Javier Cruz" Subject: Re: Pietenpol-List: Javier is back ! Hi Mike , is a pleasure to see that the old Piets (not for the age :),just on this list) still are here... I am trying to use the spare time for finish the Piet, and the first thing is update me with all things that are new on this list. About your comment, i really don't know, i think that all planes have it "enchantment" and the Piet have something extra , maybe because is made by your hands. I will post the advances here Thanks for your welcome. pd .I feel good that the Piets like the Mexican "gifts" ... ________________________________ Message 46 ____________________________________ Time: 10:14:30 PM PST US From: jorge lizarraga Subject: Re: Pietenpol-List: hickory wood ok soun great tanks oscar for the inform i like to have wood I see pictured fr om piet finished whit those parts from wood ala ww1 plane stails seyou nex --- On Thu, 10/8/09, Oscar Zuniga wrote: From: Oscar Zuniga Subject: Pietenpol-List: hickory wood Jorge; I think hickory wood is what is commonly used foraxe handles.- You can also use ash if you are making cabane struts from wood.- You could probably also use oak. Speaking of hickory axe handles, and going back to earlier posts about making the wing tip bows out of something durable to resist groundloop scrapes, you could also install axe handle outriggers like the tri-wing Fokker airplanes had, to do the same thing.- Sort of like training wheels ;o) Oscar Zuniga Air Camper NX41CC San Antonio, TX mailto: taildrags@hotmail.com website at http://www.flysquirrel.net --- -------- ------ --- - le, List Admin. =0A=0A=0A ------------------------------------------------------------------------------------- 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.