---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Wed 09/29/04: 36 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:05 AM - Kawasaki 340/440 Reduction Drive () 2. 05:07 AM - Re: Aircamper w/ Corvair conversion at Copperstate (N321TX@wmconnect.com) 3. 05:15 AM - Re: Scimitar Prop () 4. 05:25 AM - Copperstate Fly-In Oct. 7-10, Casa Grande, AZ (Michael D Cuy) 5. 05:37 AM - Space Ship One vs. Pietenpol Air Camper (Michael D Cuy) 6. 06:45 AM - magnetos for a C-85 (Sayre, William G) 7. 07:39 AM - Firewall question (Rick Holland) 8. 07:47 AM - Another firewall question (Rick Holland) 9. 08:11 AM - Re: Firewall question (BARNSTMR@aol.com) 10. 08:12 AM - Re: Another firewall question (BARNSTMR@aol.com) 11. 08:22 AM - Re: Firewall question (BARNSTMR@aol.com) 12. 08:29 AM - Re: Firewall question (BARNSTMR@aol.com) 13. 08:47 AM - Re: Firewall question (Richard Navratil) 14. 08:52 AM - scimitar prop (Oscar Zuniga) 15. 09:12 AM - fluting the firewall (Michael D Cuy) 16. 09:47 AM - Re: Firewall question () 17. 10:18 AM - Re: Another firewall question (John Dilatush) 18. 10:53 AM - Re: Scimitar Prop (Gary Gower) 19. 01:10 PM - Re: Another firewall question (Gordon Bowen) 20. 01:49 PM - Re: Re: Another firewall question () 21. 02:48 PM - Re: Firewall question (BARNSTMR@aol.com) 22. 03:46 PM - Fuel strainer mesh (Isablcorky@aol.com) 23. 03:56 PM - Letter to Greg, wing making (John Dilatush) 24. 05:10 PM - Re: Firewall question (walt evans) 25. 05:19 PM - Scimitar props (TBYH@aol.com) 26. 05:37 PM - Re: Fuel strainer mesh (Dale Johnson) 27. 05:41 PM - Re: Fuel strainer mesh (Isablcorky@aol.com) 28. 05:45 PM - Re: Scimitar props (Rcaprd@aol.com) 29. 05:54 PM - Re: Another firewall question... (Gary Gower) 30. 05:56 PM - 340 / 440 Kawasaki re-drive () 31. 06:24 PM - Re: Fuel strainer mesh (Isablcorky@aol.com) 32. 07:55 PM - Re: Letter to Greg, wing making (Greg Bacon) 33. 09:11 PM - Re: Fuel strainer mesh (Richard Navratil) 34. 09:15 PM - Re: Scimitar Prop (Richard Navratil) 35. 10:00 PM - Re: Looking for a GN-1... (Steve Ruse) 36. 10:44 PM - Fw: Piets for Sale (Clif Dawson) ________________________________ Message 1 _____________________________________ Time: 05:05:23 AM PST US From: Subject: Pietenpol-List: Kawasaki 340/440 Reduction Drive --> Pietenpol-List message posted by: I am beyond "very intersted" in making my own reduction drive for my 340/A. Has anyone gone down this road? I also need to convert to a CDI and wire for an electric starter. Any advice or time saving information would be GREATLY appreciated. Bes Regards, Tim ________________________________ Message 2 _____________________________________ Time: 05:07:06 AM PST US From: N321TX@wmconnect.com Subject: Re: Pietenpol-List: Aircamper w/ Corvair conversion at Copperstate More details needed for Copperstate please. When and where? I might try and make it as I'm becoming more and more interested in the Corvair engine. Also, in addition to the identifying characteristics that Mr. Vegh mentioned, as you attempt to seek him out in a crowd, look for the neatest car in the whole darned parking lot (if he doesn't drive his truck.) S.B. ________________________________ Message 3 _____________________________________ Time: 05:15:30 AM PST US From: Subject: Re: Pietenpol-List: Scimitar Prop --> Pietenpol-List message posted by: Chuck, If you need one more reason to build a scimitar prop it is this, they look REALLY COOL! Greg Cardinal Minneapolis ----- Original Message ----- From: Subject: Pietenpol-List: Scimitar Prop > --> Pietenpol-List message posted by: Rcaprd@aol.com > > I'm going to see if I can kick up any interest in the design of a 'Scimitar > Prop'. I've brought up this subject in years past on this list, but had only > limited interest. > Lots of good stuff snipped...... ________________________________ Message 4 _____________________________________ Time: 05:25:22 AM PST US From: Michael D Cuy Subject: Pietenpol-List: Copperstate Fly-In Oct. 7-10, Casa Grande, AZ 0.25 BLANK_LINES_70_80 BODY: Message body has 70-80% blank lines --> Pietenpol-List message posted by: Michael D Cuy Sterling--- here is the Copperstate Regional Fly-In web site. Mike C. http://www.copperstate.org/ ________________________________ Message 5 _____________________________________ Time: 05:37:10 AM PST US From: Michael D Cuy Subject: Pietenpol-List: Space Ship One vs. Pietenpol Air Camper --> Pietenpol-List message posted by: Michael D Cuy Guys-- after too much coffee this morning I was wondering how long it would take a Pietenpol to climb as high as Space Ship One is going to fly today over Mojave, California. They need to climb at least 62 miles which is 327,360 feet. At 400 fpm climb rate that would take us 13.6 hours in a Pietenpol. Wear mittens. Mike C. do not archive ________________________________ Message 6 _____________________________________ Time: 06:45:57 AM PST US Subject: Pietenpol-List: magnetos for a C-85 From: "Sayre, William G" --> Pietenpol-List message posted by: "Sayre, William G" I am in need of a pair of magnetos for a C-85-12F. Bendix (S4LN-21 10-51360-26) or Slick (4301L.H or 4371). If you have a lead, please contact me off-list (bannerbill@att.net). Thanks, Bill Sayre Do not archive ________________________________ Message 7 _____________________________________ Time: 07:39:44 AM PST US From: Rick Holland Subject: Pietenpol-List: Firewall question --> Pietenpol-List message posted by: Rick Holland Ordered a sheet of .016" stainless for my firewall and would like some advice. Bingelis recommends placing insulation between the firewall and sheet metal like Fiberfrax. What have you guys used for this and how thick? Have seen several pictures that looked like the metal was bolted directly to the 1/8" ply. Thanks -- Rick Holland ________________________________ Message 8 _____________________________________ Time: 07:47:26 AM PST US From: Rick Holland Subject: Pietenpol-List: Another firewall question --> Pietenpol-List message posted by: Rick Holland Is there any need to flute the edges of the firewall sheet metal on a Piet? (As shown in Firewall Forward) or do you just cut the sheet to match the same dimentions of the firewall ply? Thank You -- Rick Holland ________________________________ Message 9 _____________________________________ Time: 08:11:06 AM PST US From: BARNSTMR@aol.com Subject: Re: Pietenpol-List: Firewall question --> Pietenpol-List message posted by: BARNSTMR@aol.com Ol Tony B. was a smart feller. I would follow his recommendation. Here's my logic and I suspect Tony's, too. From the standpoint of what is a minimum safe requirement for certified airplanes... The FAA requires the firewall material be "fireproof". Their definition is that it must resist flame penetration for 15 minutes when exposed to a 2000 degree F flame. .016 stainless has been proven to meet this requirement. So, consider the wood on the backside of the heated steel. I am not sure of the exact temperature...but the auto-ignition temperature of wood is lower than 2000 degrees F. So even though the steel prevents flame penetration, the wood will burn due to the high heat radiating thru the steel sheet. So to meet the intent of the FAA regulation for wood-backed firewalls, insulation is necessary. Now, from the practical standpoint, imagine yourself with an inflight engine fire. Your first action should be to turn off the fuel. Hopefully your fuel shut-off alve is aft of the firewall (also a requirement for certified airplanes) and will thus be protected from heat. It is likely that the engine fire would extinguish if the fuel is valve is off. But theres a chance that your fiberglass resin nose cowl or smoke oil tank or something else is still on fire. Now think of your passenger up front and that nose fuel tank. If I am in that situation... The main thing I need is time to safely land the airplane and get myself and passenger out before the fire spreads thru the firewall to that fuel tank. So to answer the question of how thick the insulation should be.... I plan to do my own simple test. Take a 12" X 12" sample of the stainless material, backed with the insulation material, and wood. Expose it to a carburizing flame (the blue area is approx 2000 deg. F) and see how much time you will have to land the airplane before the wood ignites. Insulation is also helpful for keeping the fron passenger cool on hot days. -- Terry L. Bowden ph 254-715-4773 fax 254-853-3805 ________________________________ Message 10 ____________________________________ Time: 08:12:16 AM PST US From: BARNSTMR@aol.com Subject: Re: Pietenpol-List: Another firewall question --> Pietenpol-List message posted by: BARNSTMR@aol.com I'd just look at it from the standpoint of which edge finishing technique does the best job of keeping heat away from the wood structure. -- Terry L. Bowden ph 254-715-4773 fax 254-853-3805 ________________________________ Message 11 ____________________________________ Time: 08:22:50 AM PST US From: BARNSTMR@aol.com Subject: Re: Pietenpol-List: Firewall question --> Pietenpol-List message posted by: BARNSTMR@aol.com About Fiberfrax... This is a brand name for some high tech woven and spun-bonded fiberglass materials. There are other brands as well. Depending on the grade, it comes in different heat ratings. The good stuff can be expensive. But there are some reasonable materials out there. I haven't done the research yet for my project...but I worked with this stuff several years ago for some aircraft exhaust insulation applications. I plan to do some research on this before making my purchase. -- Terry L. Bowden ph 254-715-4773 fax 254-853-3805 ________________________________ Message 12 ____________________________________ Time: 08:29:08 AM PST US From: BARNSTMR@aol.com Subject: Re: Pietenpol-List: Firewall question --> Pietenpol-List message posted by: BARNSTMR@aol.com I was wrong... it is CERAMIC fiber and not glass fiber. heres a link. Do a google search for "ceramic fiber insulation"... or "Fiberfrax". http://www.infraredheaters.com/insulati.htm -- Terry L. Bowden ph 254-715-4773 fax 254-853-3805 ________________________________ Message 13 ____________________________________ Time: 08:47:57 AM PST US From: "Richard Navratil" Subject: Re: Pietenpol-List: Firewall question --> Pietenpol-List message posted by: "Richard Navratil" I covered my firewall with a fireproof mat from ASS. and the top section with a 1" insulated fireproofing. The inspector at sign off commented that even without the extras, before burn thru of the firewall, with a wod plane, I would have some other things to think about. He would have been OK without it. Dick N. ----- Original Message ----- From: "Rick Holland" Subject: Pietenpol-List: Firewall question > --> Pietenpol-List message posted by: Rick Holland > > Ordered a sheet of .016" stainless for my firewall and would like some > advice. Bingelis recommends placing insulation between the firewall > and sheet metal like Fiberfrax. What have you guys used for this and > how thick? Have seen several pictures that looked like the metal was > bolted directly to the 1/8" ply. > > Thanks > > -- > Rick Holland > > ________________________________ Message 14 ____________________________________ Time: 08:52:13 AM PST US From: "Oscar Zuniga" Subject: Pietenpol-List: scimitar prop --> Pietenpol-List message posted by: "Oscar Zuniga" Chuck; There have been many scimitar props built and flown. For a really interesting one, see recent Contact! magazine #76 on David Roe's highly modified Hummelbird airplane with "Aeromorph" super short-stroke VW engine and... scimitar prop. It's made of oak laminations (the hub and about half of each blade), with the tips and the outer half of each blade made of a composite material for resistance to erosion. I don't know that it is intentionally designed to flex in torsion to change the blade angle of attack, but I would suspect that it does some of that simply due to the scimitar shape and the inherent flexibility of the composite material. Warnke's "Almost Constant Speed" wood props have always touted this as a feature of the design... with a bit of torsional flexure to allow changing angle of attack at various engine loads. Oscar Zuniga San Antonio, TX ________________________________ Message 15 ____________________________________ Time: 09:12:42 AM PST US From: Michael D Cuy Subject: Pietenpol-List: fluting the firewall Rick-- I fluted my curved portion ala Tony B. and it worked great. I wanted the firewall to not just lay over the plywood but to overlap the edges all the way around. I have a few small wood screws securing it to the 1/8" birch ply firewall and a very thin layer of fiberfrax we were throwing away at work here years ago. I don't know where you could find that stuff---possibly Wicks or ACS ? Dunno. This photo kinda shows the wrap around idea---least on the sides. Mike ________________________________ Message 16 ____________________________________ Time: 09:47:27 AM PST US From: Subject: Re: Pietenpol-List: Firewall question --> Pietenpol-List message posted by: I used fiberfrax for mine. Jack Phillips > > From: Rick Holland > Date: 2004/09/29 Wed AM 10:39:28 EDT > To: pietenpol-list@matronics.com > Subject: Pietenpol-List: Firewall question > > --> Pietenpol-List message posted by: Rick Holland > > Ordered a sheet of .016" stainless for my firewall and would like some > advice. Bingelis recommends placing insulation between the firewall > and sheet metal like Fiberfrax. What have you guys used for this and > how thick? Have seen several pictures that looked like the metal was > bolted directly to the 1/8" ply. > > Thanks > > -- > Rick Holland > > > > > > > > > ________________________________ Message 17 ____________________________________ Time: 10:18:39 AM PST US From: "John Dilatush" Subject: Re: Pietenpol-List: Another firewall question --> Pietenpol-List message posted by: "John Dilatush" ----- Original Message ----- From: "Rick Holland" Subject: Pietenpol-List: Another firewall question > --> Pietenpol-List message posted by: Rick Holland ============================= Rick, I used fiberfrax in between the ply firewall and .020 aluminum. Then around the edges of the firewall in order to mount the cowling, I made up some angle of .040 aluminum measuring .75 x .75 inches. This was fluted (shrunk) on one leg to fit the rounded top to the firewall and then screwed through the aluminum/fiberfrax/plywood sandwich. Hope this helps, John ================================ > > Is there any need to flute the edges of the firewall sheet metal on a > Piet? (As shown in Firewall Forward) or do you just cut the sheet to > match the same dimentions of the firewall ply? > > Thank You > > -- > Rick Holland > > ________________________________ Message 18 ____________________________________ Time: 10:53:28 AM PST US From: Gary Gower Subject: Re: Pietenpol-List: Scimitar Prop --> Pietenpol-List message posted by: Gary Gower Hello Chuck, The Scimitar propellers are more popular in Europe, were gasoline is more expensive, so they try to get all the trust possible of less powerfull engines. In USA was better (still now) to install a more powerfull engine (easy available, cheaper gas) and use a normal prop. Years ago I did some research, to use in my VW conversions, but instead tried the "almost constant speed propeller" instructions by Mr. Hess, this booklet was sold in Sport Aviation some years ago, the results were good enough and the props were more easy to carve... the plane was sold with the engine prop combination and flew fine, lost contact with the actual owner some time ago. (I think I mentioned this to you about a year or two ago??) maybe "scimitar propeller" in google can get some results... because "Scimitar" is a popular car and floods the search. Just imagine a radial engine with a Scimitar propeller, just beautyfull... Saludos Gary Gower. Do not archive. --- Rcaprd@aol.com wrote: > --> Pietenpol-List message posted by: Rcaprd@aol.com > > I'm going to see if I can kick up any interest in the design of a > 'Scimitar > Prop'. I've brought up this subject in years past on this list, but > had only > limited interest. > As we all know, a propeller absorbs the energy of the fuel burned > in the > engine, and dispenses it in the form of thrust. Whenever energy is > transformed from one form to another, some energy is transformed to > some other form > which is lost to intent of thrust. Energy cannot be created nor > destroyed...it's > a fact of physics. Therefore, the more efficiently the 'Potential' > energy of > the fuel that is burned, can be transformed into thrust, the less > fuel will be > required to perform a given amount of work. A given fixed pitch prop > is most > efficient at a specific r.p.m., and a specific forward speed. This > is why > adjustable props came into play, and high performance airplanes > usually have > Constant Speed Props. Here is where the Scimitar Prop comes in. The > blades of > the Scimitar Prop will twist to a lower blade angle for the high > thrust > required for takeoff and climb, then once airborne and power is > pulled, the prop > unloads and flexes back almost to the blade angle it was carved at. > Hence you > have an adjustable blade angle prop, with No Moving Parts !! Pretty > cool, huh? > Wood is the chosen material for this design, because it will not > fatigue, it's > readily available, and it's relatively easy to work with. > > Here are the forces imposed upon a Propeller: > > 1. Centrifugal Force - Most powerful force, tends to pull the > blades > outward away from the hub. > > 2. Thrust Bending Force - Blade tips bend forward when put > under a load. > > 3. Torque Bending Force - Blades bend opposite the direction of > > rotation. > > 4. Aerodynamic Twisting Force - Twists the blade at the > aerodynamic > center of pressure. Tends to twist the blades to High Pitch. > > 5. Centrifugal Twisting Force - The Mass of the blade, under a > centrifugal force, tends to twist the blades to a Lower Pitch. > > 6. Vibration Force (Resonance) - Everything has a resonant > frequency, > according to the mass, and the location of the mass. > > A Scimitar design prop takes advantage of these forces to twist > the > blades to a lower blade angle for takeoff and climb, and then when in > cruise flight > and power is pulled back, and the prop unloads, the blade angle > relaxes back > to a higher blade angle, and you have a cruise prop. > Steve Wittman certainly understood the potential of a scimitar > design, as > evidence on the wall of his hanger in Oshkosh. > I still can't understand why all props aren't of scimitar design. > With > enough Research and Development, then mass production could easily > bring the > additional labor involved, down to a competitive cost. I have > searched the > library at Oshkosh, lots of web sites, and asked lots of people about > scimitar > props. By far, the best info I've found on it, is the couple of > pages in Eric > Clutton's book. I did, however, discover that the concept came about > in W.W.I > aircraft. The design showed potential, but what happened on several > occasions > was that in a dogfight, the lead plane would go into a dive, in an > effort to > escape the aggressor, and the engine / prop would overspeed, then the > blades > would begin to flutter, and disintegrate. You can imagine the > vibration of a > broken prop blade, and if power wasn't pulled and shut down the > engine, it would > then shake the engine right off the plane, and now, with a tail heavy > CG > condition, the plane would spin to the ground. Even if the pilot was > able to shut > down the engine in time, he was then a glider pilot...easy prey. I > believe > when you over-run the prop of a scimitar design, the aerodynamics are > what > cause the flutter. I have heard stories about how props de-laminate > when using > thin laminates of wood, however these props had the width of the > planks in the > conventional direction. The cause of these de-laminations could also > have been > the technique of construction. The big question, is if any > successful props > were built using the parameters that Eric Clutton set forth. I do > not know > the answer to that question. > I still plan of building one, but haven't began construction, > yet. The > method of construction I would use, is laminates of 1/4" or less, > bend each > laminate in a jig, to match the 'S' shape of the prop, and use T88 > exclusively, > but to avoid squeezing too much of the adhesive out, by using either > scrim > cloth between the laminates, or glass beads in the mixture of epoxy. > The type of > wood would I'll use, is still undecided yet, but the type of types of > > acceptable prop wood is called out in the AC 43.13-1A. > Now, the challenge of designing a reliable Scimitar Prop, using > the mass > of the blade to twist the blade to a lower blade angle for takeoff > and climb, > then back almost to the blade angles that they were cut at, when the > prop > unloads. The laminations would be perpendicular to the direction of > conventional > props, so as to achieve the dramatic arc of the blades, as set forth > by Eric > Cluttons design. > I'm looking for any input, pros or cons, and especially if anyone > is > aware of an aircraft that has used this design prop successfully. > > > Chuck Gantzer > Pietenpol Aircamper > NX770CG ________________________________ Message 19 ____________________________________ Time: 01:10:30 PM PST US From: "Gordon Bowen" Subject: Re: Pietenpol-List: Another firewall question --> Pietenpol-List message posted by: "Gordon Bowen" I don't think Aluminum for a firewall is considered legal by the FAA, because it will burn. The Brits found the problem of aluminum's burning hot during the loss of one of their ships during the Falkland's war. Small missle set the aluminum on fire and burnt the ship. Missle damage was small, aluminum fire was a disaster. Re; the question of fibefrax, this is just aluminum oxide ceramic fibers "ceramic", I think just about any insulation material like dry fiberglass (silicon oxide ceramic) functions just as well. But bottom line, the "dope" used on the Dacron fabric will be burning real good, long long before an engine fire could burn thru 16-20 ga. galvanized steel over plywood. For those who'd like to save a little wt. forward of the CG, and live near the Boeing surplus store near Auburn WA, the surplus store sells titanium sheet about 20 ga., as scrap metal, cheap and very light weight. None of the ole store-bought certified ragwings have any insulation between the engine and fuselage, just a galvanized steel sheet. The FAA only requires as non-flammable firewall between the pilot and engine. I agree with an earlier posting- if the fire burns thru galvanized steel, and starts scorching the plywood, you've already got more problems than you'd want to be dealing with if still airborne. Gordon Bowen ----- Original Message ----- From: "John Dilatush" Subject: Re: Pietenpol-List: Another firewall question > --> Pietenpol-List message posted by: "John Dilatush" > > > ----- Original Message ----- > From: "Rick Holland" > To: > Sent: Wednesday, September 29, 2004 8:47 AM > Subject: Pietenpol-List: Another firewall question > > > > --> Pietenpol-List message posted by: Rick Holland > ============================= > Rick, > > I used fiberfrax in between the ply firewall and .020 aluminum. Then > around the edges of the firewall in order to mount the cowling, I made up > some angle of .040 aluminum measuring .75 x .75 inches. This was fluted > (shrunk) on one leg to fit the rounded top to the firewall and then screwed > through the aluminum/fiberfrax/plywood sandwich. > > Hope this helps, > > John > ================================ > > > > Is there any need to flute the edges of the firewall sheet metal on a > > Piet? (As shown in Firewall Forward) or do you just cut the sheet to > > match the same dimentions of the firewall ply? > > > > Thank You > > > > -- > > Rick Holland > > > > > > > > > > > > > > > > > > ________________________________ Message 20 ____________________________________ Time: 01:49:13 PM PST US From: Subject: Re: Re: Pietenpol-List: Another firewall question --> Pietenpol-List message posted by: The "Dope" won't burn if you use the PolyFiber process. It does not support combustion. Having lost a friend who burned up in an otherwise survivable crash due to the fabric burning, I consider this the primary reason to use Stit's PolyFiber process. Jack > > From: "Gordon Bowen" > Date: 2004/09/29 Wed PM 04:08:38 EDT > To: > Subject: Re: Pietenpol-List: Another firewall question > > --> Pietenpol-List message posted by: "Gordon Bowen" > > I don't think Aluminum for a firewall is considered legal by the FAA, > because it will burn. The Brits found the problem of aluminum's burning hot > during the loss of one of their ships during the Falkland's war. Small > missle set the aluminum on fire and burnt the ship. Missle damage was > small, aluminum fire was a disaster. > > Re; the question of fibefrax, this is just aluminum oxide ceramic fibers > "ceramic", I think just about any insulation material like dry fiberglass > (silicon oxide ceramic) functions just as well. But bottom line, the "dope" > used on the Dacron fabric will be burning real good, long long before an > engine fire could burn thru 16-20 ga. galvanized steel over plywood. For > those who'd like to save a little wt. forward of the CG, and live near the > Boeing surplus store near Auburn WA, the surplus store sells titanium sheet > about 20 ga., as scrap metal, cheap and very light weight. None of the ole > store-bought certified ragwings have any insulation between the engine and > fuselage, just a galvanized steel sheet. The FAA only requires as > non-flammable firewall between the pilot and engine. I agree with an > earlier posting- if the fire burns thru galvanized steel, and starts > scorching the plywood, you've already got more problems than you'd want to > be dealing with if still airborne. > Gordon Bowen > > > > ----- Original Message ----- > From: "John Dilatush" > To: > Sent: Wednesday, September 29, 2004 9:17 AM > Subject: Re: Pietenpol-List: Another firewall question > > > > --> Pietenpol-List message posted by: "John Dilatush" > > > > > > ----- Original Message ----- > > From: "Rick Holland" > > To: > > Sent: Wednesday, September 29, 2004 8:47 AM > > Subject: Pietenpol-List: Another firewall question > > > > > > > --> Pietenpol-List message posted by: Rick Holland > > ============================= > > Rick, > > > > I used fiberfrax in between the ply firewall and .020 aluminum. Then > > around the edges of the firewall in order to mount the cowling, I made up > > some angle of .040 aluminum measuring .75 x .75 inches. This was fluted > > (shrunk) on one leg to fit the rounded top to the firewall and then > screwed > > through the aluminum/fiberfrax/plywood sandwich. > > > > Hope this helps, > > > > John > > ================================ > > > > > > Is there any need to flute the edges of the firewall sheet metal on a > > > Piet? (As shown in Firewall Forward) or do you just cut the sheet to > > > match the same dimentions of the firewall ply? > > > > > > Thank You > > > > > > -- > > > Rick Holland > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ________________________________ Message 21 ____________________________________ Time: 02:48:56 PM PST US From: BARNSTMR@aol.com Subject: Re: Pietenpol-List: Firewall question --> Pietenpol-List message posted by: BARNSTMR@aol.com While we're on this subject,... has anyone ever heard of a pietenpol having an in-flight fire? -- Terry L. Bowden ph 254-715-4773 fax 254-853-3805 ________________________________ Message 22 ____________________________________ Time: 03:46:24 PM PST US From: Isablcorky@aol.com Subject: Pietenpol-List: Fuel strainer mesh Pieters, Would anyone know a source of fine wire mesh suitable for gascolator and carb inlet? Would appreciate a little help. Corky ________________________________ Message 23 ____________________________________ Time: 03:56:16 PM PST US From: "John Dilatush" Subject: Pietenpol-List: Letter to Greg, wing making Pieters, I just finished a letter to Greg Bacon, the fellow that bought my "Wounded Piet" After rereading it, it occurred to me that this information might be of use to some ot the newer members of the list who are maybe just starting to build a Pietenpol. I am sure that Greg knows most of this stuff, but I guess it won't hurt to repeat it. So with Greg's and your indulgence, I am posting it here where it might be of some use to those just "coming along" John Good Morning, Greg! You asked for information about how I built the wings of "Mountain Piet" and I am happy to do so, please remember that the wings were the first item I built and that was about 10 years ago. I don't think that I am senile yet, but my wife will tell you that my memory is certainly less than perfect! When starting to build the ribs, I checked the drawing that Pietenpol sent with the plans of the ribs against the coordinates that were shown. There was quite a discrepancy between the two and so I elected to layout a new drawing using the coordinates. These coordinates will not provide a smooth line, so you will have to make a batten and use it to connect the majority of the points and get a smooth line. After doing this I made a jig using the drawing and using the =BD X =BD inch cap and truss members as shown on the plans. The jig, which unfortunately I have now tossed, had small cams where needed so as to hold the rib members tightly against the blocks thus insuring accuracy. I then started to cut wood and used Engleman spruce, a locally available material which is a close relative of Sitka spruce except lighter in weight. The drawback to this material is that it has a number of small knots and you must choose the strips after milling which are free of these imperfections. I would think you could certainly use Sitka spruce (which is really expensive) or cedar as Charlie Rubeck uses just as well. I milled my own material, first planing the boards to an accurate =BD inch in thickness and then running these through my table saw into strips slightly larger than =BD inch. The grain for the capstrips was kept vertical to the wing span so there would be less deformation with the pull of the fabric. I then made up, without gluing it together, a rib in the jig using these strips and laid out templates for the gussets. I then set up the saw to cut out all the required components of the ribs. I cut the angles accurately, however, left the lengths a little long for a more accurate fit up later when putting them in the jig. These strips and gussets were then sorted out into a bunch of containers, coffee cans work fine. I made up a jig for bending the front of the top cap strips (four at a time) after soaking them in boiling water for a few minutes until they were flexible. They were then put in the jig and left overnight to dry, ready for the next days work. The 1/16 inch mahogany plywood gussets were sanded to remove any glaze so as to have better adhesion using T-88 epoxy. Actual assembly of the ribs went smoothly but I could only make about one rib a day because I let the epoxy dry completely before removing the rib from the jib. A tight fit of the rib members was done by using a disk sander and lightly touching the end of the precut parts to the sanding disk until I got the exact length needed. Gussets, of course, were only put on the top side of the rib in the jig and then the other side was put on the next day. The jig was protected from the adhesive by a piece of Saran Wrap laid over the top of the entire jig before putting in the rib components. These components were pressed down into the Saran Wrap into the jig as they were fitted and glued. This way avoided any epoxy getting into the jig and sticking the rib. The dimension that you cut slightly more than =BD inch should be above the capstrips so you have some material to sand down to the exact =BD inch of the capstrip. Before putting on the gussets I block sanded the entire side of the rib so that all parts were level with one another and then used an air hose to get rid of the sanding dust. Gussets were left a little high above and below the cap strips so they could be sanded down to be even with the cap strip later. The gussets were fastened with small 3/8 inch aircraft nails. I found that using a automatic (spring loaded) brad setter such as picture framers use, worked well. You might be able to get this at your friendly hardware store, but probably will have to find it yourself because the clerk won't know what you are looking for! I put a few strategically placed holes in the bottom of the jig, so that the part might be pushed out if it was reluctant to pop out by itself. When the gussets were put on the opposite side of the rib the next day, again I block sanded the entire side of the rib so that the gussets would lie flat. After the ribs were done, I made up a couple of false stub spars and mounted the entire set of ribs to these. Then it was possible to sand off all the protruding gussets and block sand the ribs all to exactly the same contour. When gluing, be sure to wipe all the surplus epoxy off of the joints, not to make them stronger or anything, just to massage your own ego! Spars are =BE inch vertical grain fir. There are, at least in my area some dealers that handle this material, and if you explain the project, hopefully developing their enthusiasm, they will let you go through their stock to pick out that most suited for you. I believe there is an EAA publication outlining the specs for the material you need, it's called "EAA Aircraft Building Techniques, Wood" I did not use the little wood wedges that Mr. Pietenpol shows on the plans, but simply cut the top of the spar to fit the angle. The cheek plates for fittings are made of 1/16 and 1/8 ply as needed. Be sure to sand the plywood before gluing with, again T-88 epoxy. The tip bow is laminated and you should be able to use the one on the salvaged wing, along with all the metal fittings. Just sandblast the fittings and refinish. Since we are in a dry climate here, I protected the fittings with just a coat of "Krylon" primer and then a topcoat of the same brand. Build yourself a table to assemble the wing on. It needs to be flat and level and build it long enough to hold both the wing and center section. You will build the wing on the table to the existing center section so that when everything is put together on the plane, it will fit with no surprises. I would suggest that you slide the ribs on the spar and before permanently fastening them down, that you put in the drag and antidrag cables and then adjust the spacing of the ribs slightly to clear them. You can see that I didn't do this and had to in several places put on some doublers and cut the truss members to avoid the wires. Also, even though the plans call for 1" nails to fasten the ribs to the main spar, these are too long. Instead, you only need to use about a =BD inch long nail, and be sure you drive these in the exact center of the spar (the neutral axis) only. This is to avoid weakening the spar. The epoxy is really the connection to the spar, the nail is only to clamp the rib to the spar until the epoxy sets. The leading and trailing edges use the same wood as you will use for the ribs. Block all the trailing edges of the ribs to the same height and cut the trailing edge to the same angles as the ribs, just a little larger than the finished part will be. You will need to scarf the trailing edge in some place, because it is doubtful that you will have a long enough piece to do it all in one shot. Now here is where I differed from the plans. You will notice that I made up 1/8 inch plywood biscuits and then used these to connect the trailing edge to the ribs. To do this I made up a jig incorporating a router and biscuit cutter that can be used on both the rib and trailing edge. I am lending this to you and will send it along with the plans that I forgot to give you before. Just return it when you are done. The leading edge is made up the same way as the trailing edge, scarfed and run through the table saw to the approximate angles as the rib and plans show. I made it just a little oversized and then rabbited the plywood on the top leading edge into the solid leading edge. You can see how this was done on the salvage wing. Don't put any support for the rear edge of the ply. Without any support, the fabric will pull down the ply between the ribs and then there is a smooth transition for the airflow. Bernie was one darned smart feller! I used Australian Hoop Pine, this is advertised in the magazines. Don't remember the thickness, but you can measure what is there and order what you need. This stuff comes in 5 foot lengths and will have to be scarfed together. I made up a jig to hold the proper angle and then used a drum sander on my radial arm saw to cut the work pieces. The leading edge is bolted in place and then hand finished with a jack plane and rough 80 grit sanding block to the final shape. I would suggest that you make a template of the leading edge of the good wing so that the leading edges of the two wing panels are the same. This will help to ensure that once you have the rigging right, the there will be less of a tendency for one wing to stall first. After the wing is assembled, be sure to "trammel" wing and adjust the cables to get the wing perfectly square. Use the "twang method" to get even tension. They don't have to be super tight, just taut with little strain on the fittings. Now its time to go to work with the sandpaper again. Work up to about a 220 grit and then varnish with "Varathane" or something similar. Put two coats on and sand between coats. Don't need to worry about a two part epoxy for finishing, the fabric cement you use later will dry quickly enough that it will not attack the finish. It might just soften it a little and really provides a better bond when cured. At this point, you should have a new wing, all varnished, no rough spots, connected to the center section and ready to cover. Pull the center section off, find a cool beverage and take your wife and kids away for a short vacation to make up for the time spent away from the family while building the wing. We'll talk about covering then. Cordially, John PS Made wine this last weekend from a new crop of California grapes. Won't be ready for a couple of years or more, but will enclose with the plans and router jig, a bottle of our 2000 Petit Sarah. I think you will enjoy the label! ________________________________ Message 24 ____________________________________ Time: 05:10:39 PM PST US From: "walt evans" Subject: Re: Pietenpol-List: Firewall question --> Pietenpol-List message posted by: "walt evans" Rick, There is a requirement for this. It's somewhere around .016", but I forget. Just remember it can't be aluminum. I didn't use insulation, only used a 90 deg bend on the straight sides and a "metal shrinker" to get an overlap of about 1/2" on the top curved surface. The curve came out great! walt evans NX140DL ----- Original Message ----- From: "Rick Holland" Subject: Pietenpol-List: Firewall question > --> Pietenpol-List message posted by: Rick Holland > > Ordered a sheet of .016" stainless for my firewall and would like some > advice. Bingelis recommends placing insulation between the firewall > and sheet metal like Fiberfrax. What have you guys used for this and > how thick? Have seen several pictures that looked like the metal was > bolted directly to the 1/8" ply. > > Thanks > > -- > Rick Holland > > ________________________________ Message 25 ____________________________________ Time: 05:19:51 PM PST US From: TBYH@aol.com Subject: Pietenpol-List: Scimitar props I'm not advocating one way or another, but Al Schubert did cover this topic in his book "How I Make Wood Propellers." Interesting reading and he seems to have good reasoning on the subject. Fred B. ________________________________ Message 26 ____________________________________ Time: 05:37:05 PM PST US From: "Dale Johnson" Subject: RE: Pietenpol-List: Fuel strainer mesh Hi Corky I ordered mine from McMasters they have all sizes of mesh. Dale Mpls ----- Original Message ----- From: Subject: Pietenpol-List: Fuel strainer mesh Pieters, Would anyone know a source of fine wire mesh suitable for gascolator and carb inlet? Would appreciate a little help. Corky ________________________________ Message 27 ____________________________________ Time: 05:41:50 PM PST US From: Isablcorky@aol.com Subject: Re: Pietenpol-List: Fuel strainer mesh Thanks, I tried McMaster and couldn't bring up anything but completed fixtures. I wanted some raw material. Of course I'm not sharp, even dull, on this computer. Corky ________________________________ Message 28 ____________________________________ Time: 05:45:44 PM PST US From: Rcaprd@aol.com Subject: Re: Pietenpol-List: Scimitar props --> Pietenpol-List message posted by: Rcaprd@aol.com In a message dated 9/29/04 7:20:31 PM Central Daylight Time, TBYH@aol.com writes: << I'm not advocating one way or another, but Al Schubert did cover this topic in his book "How I Make Wood Propellers." Interesting reading and he seems to have good reasoning on the subject. Fred B. >> Fred, What does Al Schubert have to say on the subject of Scimitar Props ? Chuck G. ________________________________ Message 29 ____________________________________ Time: 05:54:23 PM PST US From: Gary Gower Subject: Re: Pietenpol-List: Another firewall question... --> Pietenpol-List message posted by: Gary Gower Lets built as safety as possible, taking in account out common sense and availability of materials and tools... Just a pair or Quotes: If you are looking for perfect safety, you will do well to sit on a fence and watch the birds; but if you really wish to learn, you must mount a machine and become acquainted with its tricks by actual trial. --Wilbur Wright,1901. Insisting on perfect safety is for people who don't have the balls to live in the real world. -- Mary Shafer, NASA Ames Dryden. If we are scared of everything possible maybe we will never fly the great airplanes we built. -- Gary Gower (just thought of it). Saludos Gary Gower Do not archive _______________________________ Declare Yourself - Register online to vote today! http://vote.yahoo.com ________________________________ Message 30 ____________________________________ Time: 05:56:50 PM PST US From: Subject: Pietenpol-List: 340 / 440 Kawasaki re-drive --> Pietenpol-List message posted by: Has anyone built a reduction drive for a Kawasaki 340 or 440 who can show me the way? Best Regards, Tim ________________________________ Message 31 ____________________________________ Time: 06:24:38 PM PST US From: Isablcorky@aol.com Subject: Re: Pietenpol-List: Fuel strainer mesh Dale, Would you mind looking up the page for me? Corky ________________________________ Message 32 ____________________________________ Time: 07:55:24 PM PST US From: Greg Bacon Subject: Re: Pietenpol-List: Letter to Greg, wing making Greetings John! First I have to give credit to your consideration and generosity. John, you've gone way beyond the call of duty in the transition of the Mtn. Piet. You patiently answered all of my questions and shared your wisdom. You have always been pleasant to talk with, even when I forgot about the time zone difference and called you at 6:30AM. You carefully labeled, packaged, and shipped the spare parts and support literature (and wouldn't even let me pay for shipping). And now you take the time to pen three pages of detailed and customized build instructions. John, I sincerely thank you for everything. Pieters, John Dilatush is truly a gentleman of fine character! I'll keep the list posted on the progress of the left wing panel rebuild. My Piet build partner, Todd Baslee, and I hope to have the Mtn. Piet flying by the 2005 Piet fly-in at Brodhead. This will be a great Winter/Spring project. I'll get the wood ordered as soon as possible. Thanks for the wine. I look forward to it's arrival. Take care, Greg Greg Bacon Missouri ----- Original Message ----- From: John Dilatush To: Greg Bacon Cc: Pietenpol-list@matronics.com Sent: Wednesday, September 29, 2004 5:54 PM Subject: Pietenpol-List: Letter to Greg, wing making Pieters, I just finished a letter to Greg Bacon, the fellow that bought my "Wounded Piet" After rereading it, it occurred to me that this information might be of use to some ot the newer members of the list who are maybe just starting to build a Pietenpol. I am sure that Greg knows most of this stuff, but I guess it won't hurt to repeat it. So with Greg's and your indulgence, I am posting it here where it might be of some use to those just "coming along" John Good Morning, Greg! You asked for information about how I built the wings of "Mountain Piet" and I am happy to do so, please remember that the wings were the first item I built and that was about 10 years ago. I don't think that I am senile yet, but my wife will tell you that my memory is certainly less than perfect! When starting to build the ribs, I checked the drawing that Pietenpol sent with the plans of the ribs against the coordinates that were shown. There was quite a discrepancy between the two and so I elected to layout a new drawing using the coordinates. These coordinates will not provide a smooth line, so you will have to make a batten and use it to connect the majority of the points and get a smooth line. After doing this I made a jig using the drawing and using the =BD X =BD inch cap and truss members as shown on the plans. The jig, which unfortunately I have now tossed, had small cams where needed so as to hold the rib members tightly against the blocks thus insuring accuracy. I then started to cut wood and used Engleman spruce, a locally available material which is a close relative of Sitka spruce except lighter in weight. The drawback to this material is that it has a number of small knots and you must choose the strips after milling which are free of these imperfections. I would think you could certainly use Sitka spruce (which is really expensive) or cedar as Charlie Rubeck uses just as well. I milled my own material, first planing the boards to an accurate =BD inch in thickness and then running these through my table saw into strips slightly larger than =BD inch. The grain for the capstrips was kept vertical to the wing span so there would be less deformation with the pull of the fabric. I then made up, without gluing it together, a rib in the jig using these strips and laid out templates for the gussets. I then set up the saw to cut out all the required components of the ribs. I cut the angles accurately, however, left the lengths a little long for a more accurate fit up later when putting them in the jig. These strips and gussets were then sorted out into a bunch of containers, coffee cans work fine. I made up a jig for bending the front of the top cap strips (four at a time) after soaking them in boiling water for a few minutes until they were flexible. They were then put in the jig and left overnight to dry, ready for the next days work. The 1/16 inch mahogany plywood gussets were sanded to remove any glaze so as to have better adhesion using T-88 epoxy. Actual assembly of the ribs went smoothly but I could only make about one rib a day because I let the epoxy dry completely before removing the rib from the jib. A tight fit of the rib members was done by using a disk sander and lightly touching the end of the precut parts to the sanding disk until I got the exact length needed. Gussets, of course, were only put on the top side of the rib in the jig and then the other side was put on the next day. The jig was protected from the adhesive by a piece of Saran Wrap laid over the top of the entire jig before putting in the rib components. These components were pressed down into the Saran Wrap into the jig as they were fitted and glued. This way avoided any epoxy getting into the jig and sticking the rib. The dimension that you cut slightly more than =BD inch should be above the capstrips so you have some material to sand down to the exact =BD inch of the capstrip. Before putting on the gussets I block sanded the entire side of the rib so that all parts were level with one another and then used an air hose to get rid of the sanding dust. Gussets were left a little high above and below the cap strips so they could be sanded down to be even with the cap strip later. The gussets were fastened with small 3/8 inch aircraft nails. I found that using a automatic (spring loaded) brad setter such as picture framers use, worked well. You might be able to get this at your friendly hardware store, but probably will have to find it yourself because the clerk won't know what you are looking for! I put a few strategically placed holes in the bottom of the jig, so that the part might be pushed out if it was reluctant to pop out by itself. When the gussets were put on the opposite side of the rib the next day, again I block sanded the entire side of the rib so that the gussets would lie flat. After the ribs were done, I made up a couple of false stub spars and mounted the entire set of ribs to these. Then it was possible to sand off all the protruding gussets and block sand the ribs all to exactly the same contour. When gluing, be sure to wipe all the surplus epoxy off of the joints, not to make them stronger or anything, just to massage your own ego! Spars are =BE inch vertical grain fir. There are, at least in my area some dealers that handle this material, and if you explain the project, hopefully developing their enthusiasm, they will let you go through their stock to pick out that most suited for you. I believe there is an EAA publication outlining the specs for the material you need, it's called "EAA Aircraft Building Techniques, Wood" I did not use the little wood wedges that Mr. Pietenpol shows on the plans, but simply cut the top of the spar to fit the angle. The cheek plates for fittings are made of 1/16 and 1/8 ply as needed. Be sure to sand the plywood before gluing with, again T-88 epoxy. The tip bow is laminated and you should be able to use the one on the salvaged wing, along with all the metal fittings. Just sandblast the fittings and refinish. Since we are in a dry climate here, I protected the fittings with just a coat of "Krylon" primer and then a topcoat of the same brand. Build yourself a table to assemble the wing on. It needs to be flat and level and build it long enough to hold both the wing and center section. You will build the wing on the table to the existing center section so that when everything is put together on the plane, it will fit with no surprises. I would suggest that you slide the ribs on the spar and before permanently fastening them down, that you put in the drag and antidrag cables and then adjust the spacing of the ribs slightly to clear them. You can see that I didn't do this and had to in several places put on some doublers and cut the truss members to avoid the wires. Also, even though the plans call for 1" nails to fasten the ribs to the main spar, these are too long. Instead, you only need to use about a =BD inch long nail, and be sure you drive these in the exact center of the spar (the neutral axis) only. This is to avoid weakening the spar. The epoxy is really the connection to the spar, the nail is only to clamp the rib to the spar until the epoxy sets. The leading and trailing edges use the same wood as you will use for the ribs. Block all the trailing edges of the ribs to the same height and cut the trailing edge to the same angles as the ribs, just a little larger than the finished part will be. You will need to scarf the trailing edge in some place, because it is doubtful that you will have a long enough piece to do it all in one shot. Now here is where I differed from the plans. You will notice that I made up 1/8 inch plywood biscuits and then used these to connect the trailing edge to the ribs. To do this I made up a jig incorporating a router and biscuit cutter that can be used on both the rib and trailing edge. I am lending this to you and will send it along with the plans that I forgot to give you before. Just return it when you are done. The leading edge is made up the same way as the trailing edge, scarfed and run through the table saw to the approximate angles as the rib and plans show. I made it just a little oversized and then rabbited the plywood on the top leading edge into the solid leading edge. You can see how this was done on the salvage wing. Don't put any support for the rear edge of the ply. Without any support, the fabric will pull down the ply between the ribs and then there is a smooth transition for the airflow. Bernie was one darned smart feller! I used Australian Hoop Pine, this is advertised in the magazines. Don't remember the thickness, but you can measure what is there and order what you need. This stuff comes in 5 foot lengths and will have to be scarfed together. I made up a jig to hold the proper angle and then used a drum sander on my radial arm saw to cut the work pieces. The leading edge is bolted in place and then hand finished with a jack plane and rough 80 grit sanding block to the final shape. I would suggest that you make a template of the leading edge of the good wing so that the leading edges of the two wing panels are the same. This will help to ensure that once you have the rigging right, the there will be less of a tendency for one wing to stall first. After the wing is assembled, be sure to "trammel" wing and adjust the cables to get the wing perfectly square. Use the "twang method" to get even tension. They don't have to be super tight, just taut with little strain on the fittings. Now its time to go to work with the sandpaper again. Work up to about a 220 grit and then varnish with "Varathane" or something similar. Put two coats on and sand between coats. Don't need to worry about a two part epoxy for finishing, the fabric cement you use later will dry quickly enough that it will not attack the finish. It might just soften it a little and really provides a better bond when cured. At this point, you should have a new wing, all varnished, no rough spots, connected to the center section and ready to cover. Pull the center section off, find a cool beverage and take your wife and kids away for a short vacation to make up for the time spent away from the family while building the wing. We'll talk about covering then. Cordially, John PS Made wine this last weekend from a new crop of California grapes. Won't be ready for a couple of years or more, but will enclose with the plans and router jig, a bottle of our 2000 Petit Sarah. I think you will enjoy the label! ________________________________ Message 33 ____________________________________ Time: 09:11:25 PM PST US From: "Richard Navratil" Subject: Re: Pietenpol-List: Fuel strainer mesh Hey Corky A boat dealer should have that screen. Dick N. ----- Original Message ----- From: Isablcorky@aol.com To: pietenpol-list@matronics.com Sent: Wednesday, September 29, 2004 7:41 PM Subject: Re: Pietenpol-List: Fuel strainer mesh Thanks, I tried McMaster and couldn't bring up anything but completed fixtures. I wanted some raw material. Of course I'm not sharp, even dull, on this computer. Corky ________________________________ Message 34 ____________________________________ Time: 09:15:00 PM PST US From: "Richard Navratil" Subject: Re: Pietenpol-List: Scimitar Prop --> Pietenpol-List message posted by: "Richard Navratil" Chuck I would like to know more about this. If you plan on pursuing this, keep me in mind. Maybe this could be a Sun N Fun project. Dick N. ----- Original Message ----- From: Subject: Pietenpol-List: Scimitar Prop > --> Pietenpol-List message posted by: Rcaprd@aol.com > > I'm going to see if I can kick up any interest in the design of a 'Scimitar > Prop'. I've brought up this subject in years past on this list, but had only > limited interest. > As we all know, a propeller absorbs the energy of the fuel burned in the > engine, and dispenses it in the form of thrust. Whenever energy is > transformed from one form to another, some energy is transformed to some other form > which is lost to intent of thrust. Energy cannot be created nor destroyed...it's > a fact of physics. Therefore, the more efficiently the 'Potential' energy of > the fuel that is burned, can be transformed into thrust, the less fuel will be > required to perform a given amount of work. A given fixed pitch prop is most > efficient at a specific r.p.m., and a specific forward speed. This is why > adjustable props came into play, and high performance airplanes usually have > Constant Speed Props. Here is where the Scimitar Prop comes in. The blades of > the Scimitar Prop will twist to a lower blade angle for the high thrust > required for takeoff and climb, then once airborne and power is pulled, the prop > unloads and flexes back almost to the blade angle it was carved at. Hence you > have an adjustable blade angle prop, with No Moving Parts !! Pretty cool, huh? > Wood is the chosen material for this design, because it will not fatigue, it's > readily available, and it's relatively easy to work with. > > Here are the forces imposed upon a Propeller: > > 1. Centrifugal Force - Most powerful force, tends to pull the blades > outward away from the hub. > > 2. Thrust Bending Force - Blade tips bend forward when put under a load. > > 3. Torque Bending Force - Blades bend opposite the direction of > rotation. > > 4. Aerodynamic Twisting Force - Twists the blade at the aerodynamic > center of pressure. Tends to twist the blades to High Pitch. > > 5. Centrifugal Twisting Force - The Mass of the blade, under a > centrifugal force, tends to twist the blades to a Lower Pitch. > > 6. Vibration Force (Resonance) - Everything has a resonant frequency, > according to the mass, and the location of the mass. > > A Scimitar design prop takes advantage of these forces to twist the > blades to a lower blade angle for takeoff and climb, and then when in cruise flight > and power is pulled back, and the prop unloads, the blade angle relaxes back > to a higher blade angle, and you have a cruise prop. > Steve Wittman certainly understood the potential of a scimitar design, as > evidence on the wall of his hanger in Oshkosh. > I still can't understand why all props aren't of scimitar design. With > enough Research and Development, then mass production could easily bring the > additional labor involved, down to a competitive cost. I have searched the > library at Oshkosh, lots of web sites, and asked lots of people about scimitar > props. By far, the best info I've found on it, is the couple of pages in Eric > Clutton's book. I did, however, discover that the concept came about in W.W.I > aircraft. The design showed potential, but what happened on several occasions > was that in a dogfight, the lead plane would go into a dive, in an effort to > escape the aggressor, and the engine / prop would overspeed, then the blades > would begin to flutter, and disintegrate. You can imagine the vibration of a > broken prop blade, and if power wasn't pulled and shut down the engine, it would > then shake the engine right off the plane, and now, with a tail heavy CG > condition, the plane would spin to the ground. Even if the pilot was able to shut > down the engine in time, he was then a glider pilot...easy prey. I believe > when you over-run the prop of a scimitar design, the aerodynamics are what > cause the flutter. I have heard stories about how props de-laminate when using > thin laminates of wood, however these props had the width of the planks in the > conventional direction. The cause of these de-laminations could also have been > the technique of construction. The big question, is if any successful props > were built using the parameters that Eric Clutton set forth. I do not know > the answer to that question. > I still plan of building one, but haven't began construction, yet. The > method of construction I would use, is laminates of 1/4" or less, bend each > laminate in a jig, to match the 'S' shape of the prop, and use T88 exclusively, > but to avoid squeezing too much of the adhesive out, by using either scrim > cloth between the laminates, or glass beads in the mixture of epoxy. The type of > wood would I'll use, is still undecided yet, but the type of types of > acceptable prop wood is called out in the AC 43.13-1A. > Now, the challenge of designing a reliable Scimitar Prop, using the mass > of the blade to twist the blade to a lower blade angle for takeoff and climb, > then back almost to the blade angles that they were cut at, when the prop > unloads. The laminations would be perpendicular to the direction of conventional > props, so as to achieve the dramatic arc of the blades, as set forth by Eric > Cluttons design. > I'm looking for any input, pros or cons, and especially if anyone is > aware of an aircraft that has used this design prop successfully. > > > Chuck Gantzer > Pietenpol Aircamper > NX770CG > > ________________________________ Message 35 ____________________________________ Time: 10:00:20 PM PST US From: "Steve Ruse" Subject: RE: Pietenpol-List: Looking for a GN-1... --> Pietenpol-List message posted by: "Steve Ruse" Thanks for the tip Joe, this one looked like a VERY nice one, but I spoke with the guy's wife today and she said he sold it several months ago. I was already starting to get excited. Steve Do not archive -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com]On Behalf Of Joe Krzes Subject: RE: Pietenpol-List: Looking for a GN-1... --> Pietenpol-List message posted by: "Joe Krzes" Steve, There is a nice one in Conroe, TX (just north of Houston). Check this link to EAA chapter 302 for details and phone number Joe Spring, TX >From: "Steve Ruse" >Subject: Pietenpol-List: Looking for a GN-1... >Date: Mon, 27 Sep 2004 00:02:53 -0500 > >--> Pietenpol-List message posted by: "Steve Ruse" > > >BlankDoes anyone know of any nice ones for sale, preferably not too far >from >Texas? I'd prefer something with a certified engine, possibly a Corvair. >I've been checking controller.com & tradeaplane for the last couple of >months, but haven't found a whole lot. There is what appears to be a nice >GN-1 in Canada, but I'm shying away from that one because I'm afraid the >paperwork & getting a thorough inspection done might be a hassle. > >If you have any pointers on what to look for, both good and bad, please let >me know! I don't know enough myself to ensure that I can avoid getting >burned. > >Thanks for any help or input! > >Steve Ruse >Irving, TX > >Do not archive > >--- >Version: 6.0.769 / Virus Database: 516 - Release Date: 9/24/2004 > > --- --- ________________________________ Message 36 ____________________________________ Time: 10:44:37 PM PST US From: Clif Dawson Subject: Pietenpol-List: Fw: Piets for Sale A friend of mine found these adds in COPA ( Canadian AOPA ) I know nothing about them. They're 3000 miles away from me. Brantford is in Ontario. Almost directly north of Erie, as the crow flies. L'Assomption is a little north of Montreal in Quebec. From the Classified Section of the September 2004 Issue of the COPA Newspaper: Category: HOMEBUILT - 1978 PEITEN POL, 2 place open cockpit tail dragger, 65 continental engine, CR moly fuselage, chrome, yellow and black paint 06/03, tail recovered, new windshields and hydraulic brakes, real sharp/must see. $21,500 Brantford area. 519-443-4142 - PIETENPOL AIRCAMPER BMV2, 750TT 250SMOH on Continental A75. Com11A, ICS ELT, two David Clark Headsets, $17,000CDN. Nice, fun, easy to fly. Hangared in L'Assomption. Call 450-582-4903 Mis-spelling (i.e.: PEITEN POL) in first ad copied directly from the printed page. Clif