---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Fri 08/26/05: 12 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:05 AM - Re: fixed landing gear (Phillips, Jack) 2. 06:08 AM - Re: Pietenpol Aircraft (hans.vander.voort@alfalaval.com) 3. 07:44 AM - Re: fixed landing gear (Dick Navratil) 4. 07:52 AM - Re: fixed landing gear (Phillips, Jack) 5. 11:23 AM - Re: fixed landing gear (Michael D Cuy) 6. 12:07 PM - Rims and Tires (Kenneth Heide) 7. 12:13 PM - Re: Rims and Tires (Phillips, Jack) 8. 12:21 PM - Re: Rims and Tires (hans.vander.voort@alfalaval.com) 9. 03:01 PM - wheels and rims (lshutks@webtv.net (Leon Stefan)) 10. 03:18 PM - Rims and Tires (Kenneth Heide) 11. 09:39 PM - Re: fixed landing gear (Dick Navratil) 12. 09:43 PM - Re: fixed landing gear (Dick Navratil) ________________________________ Message 1 _____________________________________ Time: 05:05:07 AM PST US Subject: RE: Pietenpol-List: fixed landing gear From: "Phillips, Jack" Sorry to hear that, Dick. It does confirm the stress analysis I did (unfortunately AFTER my own axle broke). The loading of this axle is somewhat peculiar in that the stress due to bending moments is constant in the area between the bungees. In other words, just sleeving the area around the bungees won't improve things, it will just move the failure point to the place where the sleeve stops. What I found when doing some research after my accident was that the gear should be sized to fail at something between 3 and 5 G's. If you make it too strong and have a very hard landing, the gear will survive but will pass the stress on to some less robust part of the airframe, causing even more expensive damage. For a steel axle to be good to 3 G's (assuming a gross weight of 1100 lbs) with no heat treating (in other words, normalized 4130 steel), a 1-1/2" axle needs to be .218" thick. To be good for 4.5 G's (3 G's plus a 150% safety factor), an un-heat treated axle would need to be solid steel, 1-1/2" diameter and still would fall somewhat short. This is why I chose to heat treat my new axle to 130,000 psi tensile strength (105,000 psi yield strength), allowing me to use the considerably lighter wall thickness of .188" and still be good to almost 5 G's. I've attached an Excel spreadsheet that calculates the axle stress. The variables you can play around with in the spreadsheet are the material yield strength (60,000 psi for normalized 4130), the distance between the center of your tire and the center of the bungee attach point, which determines the bending moment, and the axle diameter and wall thickness. You can also plug in your actual gross weight. Once again, this shows the Bernard knew what he was doing when he designed the "Improved" Air Camper with the split axle gear. The straight axle can be made very strong (the undercarriage is extremely rugged), but the axle itself is pretty heavy. The split axle gear can be equally strong with much less weight. Jack Phillips, PE Sr. Manager, Disposables Product Development Clinical Technologies and Services Cardinal Health Creedmoor, NC (919) 528-5212 -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of Dick Navratil Subject: Pietenpol-List: fixed landing gear I did an inspection of my plane tonight and found that my fixed gear axle is bent. There is about a 1" deflection in the axle,with the stbd wheel showing the bend. I had a bit of a discussion at Brodhead, with Jack Phillips on axle sizing and Jack, you are right, the 1 1/4" x .125 wall is not heavy enough for the fixed gear. I have a spare axle of the same size and will install that but will also sleeve the inside with a 1" oak dowel. I will then order a new 1 1/2" and install in down time this winter. Also, one of my cross brace cables is showing the stress threads. I just replaced the cables before Brodhead. I will up size these cables to 5/32". I belive the axle bent last Saturday when I made a full stall landing in a 15-18 kt cross wind. I should have done a wheel landing, I guess. It wasn't a horrible touchdown but there were some pretty good side loads in settling in. The Harley wheels held up very well though. This was one of those days when the wind was varied and gusting thru 50 degrees. Dick N. ________________________________ Message 2 _____________________________________ Time: 06:08:41 AM PST US Subject: Pietenpol-List: Re: Pietenpol Aircraft From: hans.vander.voort@alfalaval.com 27, 2005) at 08/26/2005 09:07:57 AM --> Pietenpol-List message posted by: hans.vander.voort@alfalaval.com Thanks Robert, No, I do not have any patterns or plans of the cowling yet. I just build it, I started off with some foam and shaped a nose bowl. This foam nose bowl became the male plug/mold for the fiberglass/ epoxy bowl I did not make a traditional female mold. This nose bowl I then mounted on the Prop hub and rest is made from Aluminum .02- 2024 Same for the Eye brows. I did not know how big to make them to get good cooling. So expected to have to remake them, either smaller or bigger. They seem however spot-on Temperature on full power climb is about 420 F At 75 Mph cruise it is around 375. And that is in Texas heat of 100 F. They might be to big for winter. The Picture gives the cowling more credit than its due, close up there are a few imperfections. But it is good enough for flight. I do intend to redo some of the Cowling, I want to make a aluminum nose bowl an redo some of the top parts. I might make some pattern drawings this winter. Hans "Robert B. Holton" cc 08/25/2005 04:46 PM Subject Pietenpol Aircraft Hans, Your Airplane is beatiful to say the least! I am in the beginning stages of building a GN-1 Aircamper, and I too want to use a William Wynne Corvair Conversion. One of the only reasons I have considered not using the Corvair is because all the Pietenpols I have seen before with this engine did not have cowlings that I thought were very attractive. Then you posted the picture of your plane. Once again what a piece of art! I immediatley focused on the way you cowled your aircraft. It appears that you have put eye brows on the plane. I love that look, but have only seen them on Pietenpols with Continentals or Lycomings. Did you design you own cowl and eye brows to fit the Covrvair Motor? If so do you have patterns left over that you may be willing to sell to other builders. Let me know I would be interested. Robert B. Holton ________________________________ Message 3 _____________________________________ Time: 07:44:17 AM PST US From: "Dick Navratil" Subject: Re: Pietenpol-List: fixed landing gear Thanks for all of that, Jack. I was planning on going to a 1.5 x .188 axle. Heat treating sounds like a very good idea. I have done that with small parts but how do you dp that on something this large? Also , did you up size your cross brace cables? Dick ----- Original Message ----- From: Phillips, Jack To: pietenpol-list@matronics.com Sent: Friday, August 26, 2005 7:04 AM Subject: RE: Pietenpol-List: fixed landing gear Sorry to hear that, Dick. It does confirm the stress analysis I did (unfortunately AFTER my own axle broke). The loading of this axle is somewhat peculiar in that the stress due to bending moments is constant in the area between the bungees. In other words, just sleeving the area around the bungees won't improve things, it will just move the failure point to the place where the sleeve stops. What I found when doing some research after my accident was that the gear should be sized to fail at something between 3 and 5 G's. If you make it too strong and have a very hard landing, the gear will survive but will pass the stress on to some less robust part of the airframe, causing even more expensive damage. For a steel axle to be good to 3 G's (assuming a gross weight of 1100 lbs) with no heat treating (in other words, normalized 4130 steel), a 1-1/2" axle needs to be .218" thick. To be good for 4.5 G's (3 G's plus a 150% safety factor), an un-heat treated axle would need to be solid steel, 1-1/2" diameter and still would fall somewhat short. This is why I chose to heat treat my new axle to 130,000 psi tensile strength (105,000 psi yield strength), allowing me to use the considerably lighter wall thickness of .188" and still be good to almost 5 G's. I've attached an Excel spreadsheet that calculates the axle stress. The variables you can play around with in the spreadsheet are the material yield strength (60,000 psi for normalized 4130), the distance between the center of your tire and the center of the bungee attach point, which determines the bending moment, and the axle diameter and wall thickness. You can also plug in your actual gross weight. Once again, this shows the Bernard knew what he was doing when he designed the "Improved" Air Camper with the split axle gear. The straight axle can be made very strong (the undercarriage is extremely rugged), but the axle itself is pretty heavy. The split axle gear can be equally strong with much less weight. Jack Phillips, PE Sr. Manager, Disposables Product Development Clinical Technologies and Services Cardinal Health Creedmoor, NC (919) 528-5212 -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of Dick Navratil Sent: Thursday, August 25, 2005 10:43 PM To: pietenpol-list@matronics.com Subject: Pietenpol-List: fixed landing gear I did an inspection of my plane tonight and found that my fixed gear axle is bent. There is about a 1" deflection in the axle,with the stbd wheel showing the bend. I had a bit of a discussion at Brodhead, with Jack Phillips on axle sizing and Jack, you are right, the 1 1/4" x .125 wall is not heavy enough for the fixed gear. I have a spare axle of the same size and will install that but will also sleeve the inside with a 1" oak dowel. I will then order a new 1 1/2" and install in down time this winter. Also, one of my cross brace cables is showing the stress threads. I just replaced the cables before Brodhead. I will up size these cables to 5/32". I belive the axle bent last Saturday when I made a full stall landing in a 15-18 kt cross wind. I should have done a wheel landing, I guess. It wasn't a horrible touchdown but there were some pretty good side loads in settling in. The Harley wheels held up very well though. This was one of those days when the wind was varied and gusting thru 50 degrees. Dick N. ________________________________ Message 4 _____________________________________ Time: 07:52:28 AM PST US Subject: RE: Pietenpol-List: fixed landing gear From: "Phillips, Jack" I didn't upsize the cables, but I used the very stiff 1x19 cable which is stronger than the 7x19. The only place I found that could heat treat an axle that long without warping is Rex Heat Treatment in Lansdale, PA. They do a lot of aerospace parts and have a vertical oven so the part doesn't lay down and warp. It was not cheap - $475 to do my axle, and it took about 6 weeks. Jack -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of Dick Navratil Subject: Re: Pietenpol-List: fixed landing gear Thanks for all of that, Jack. I was planning on going to a 1.5 x .188 axle. Heat treating sounds like a very good idea. I have done that with small parts but how do you dp that on something this large? Also , did you up size your cross brace cables? Dick N. ________________________________ Message 5 _____________________________________ Time: 11:23:35 AM PST US From: Michael D Cuy Subject: RE: Pietenpol-List: fixed landing gear --> Pietenpol-List message posted by: Michael D Cuy Dick-- my axle is about .20" thick and has survived some pretty rough landings and a groud loop when my tailwheel shoe failed. Mike C. PS-- the straight axle and wire wheels just look so go to me..I couldn't even consider the split axle version with donut tires. ________________________________ Message 6 _____________________________________ Time: 12:07:55 PM PST US From: Kenneth Heide Subject: Pietenpol-List: Rims and Tires Members of the list serve: I am seeking information on locating a supplier of aluminum rims and hubs. Also can you recommemd rims size and tires width. Along with that what about hub size and dimensions. Just seeking imput for the best possible selection. Sincerely, Kenneth M. Heide Fargo, ND ________________________________ Message 7 _____________________________________ Time: 12:13:46 PM PST US Subject: RE: Pietenpol-List: Rims and Tires From: "Phillips, Jack" What kind of wheels? Spoked "Motorcycle" type, or more traditional aircraft type wheels? Jack -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of Kenneth Heide Subject: Pietenpol-List: Rims and Tires Members of the list serve: I am seeking information on locating a supplier of aluminum rims and hubs. Also can you recommemd rims size and tires width. Along with that what about hub size and dimensions. Just seeking imput for the best possible selection. Sincerely, Kenneth M. Heide Fargo, ND ________________________________ Message 8 _____________________________________ Time: 12:21:17 PM PST US Subject: Re: Pietenpol-List: Rims and Tires From: hans.vander.voort@alfalaval.com 27, 2005) at 08/26/2005 03:21:01 PM --> Pietenpol-List message posted by: hans.vander.voort@alfalaval.com Ken, What landing gear? Split landingear is what I have, and I used Matco W62 wheels & brakes, 6 x 6.00 tires. Or straight axle gear with spoked motor cycle wheels, aerodrome aeroplanes make a nice set. Hans Kenneth Heide To Sent by: pietenpol-list@matronics.com owner-pietenpol-l cc ist-server@matron ics.com Subject Pietenpol-List: Rims and Tires 08/26/2005 02:07 PM Please respond to pietenpol-list@ma tronics.com Members of the list serve: I am seeking information on locating a supplier of aluminum rims and hubs. Also can you recommemd rimssize and tires width. Along with that what about hub size and dimensions. Just seeking imput for the best possible selection. Sincerely, Kenneth M. Heide Fargo, ND ________________________________ Message 9 _____________________________________ Time: 03:01:38 PM PST US ETAsAhQXE4C0AvTEpp46yD6DX9tL2YmsKQIULhtztyOxcDzu51uYD+2aBBDBjlc= From: lshutks@webtv.net (Leon Stefan) Subject: Pietenpol-List: wheels and rims --> Pietenpol-List message posted by: lshutks@webtv.net (Leon Stefan) Hi Ken: I am using Hager hubs and brakes. My wheels are al. atv whels 8" by 6 wide. nice and light, but not really cheap. Leon S. Ks. ________________________________ Message 10 ____________________________________ Time: 03:18:31 PM PST US From: Kenneth Heide Subject: Pietenpol-List: Rims and Tires Members of the list: I am interested in aluminum spoked rims and the width of the motorcycle tire. This also include suppliers of such, along with size of wheels, etc.....Sorry for the confusion! Ken Heide ________________________________ Message 11 ____________________________________ Time: 09:39:35 PM PST US From: "Dick Navratil" Subject: Re: Pietenpol-List: fixed landing gear OUCH ----- Original Message ----- From: Phillips, Jack To: pietenpol-list@matronics.com Sent: Friday, August 26, 2005 9:52 AM Subject: RE: Pietenpol-List: fixed landing gear I didn't upsize the cables, but I used the very stiff 1x19 cable which is stronger than the 7x19. The only place I found that could heat treat an axle that long without warping is Rex Heat Treatment in Lansdale, PA. They do a lot of aerospace parts and have a vertical oven so the part doesn't lay down and warp. It was not cheap - $475 to do my axle, and it took about 6 weeks. Jack -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of Dick Navratil Sent: Friday, August 26, 2005 10:44 AM To: pietenpol-list@matronics.com Subject: Re: Pietenpol-List: fixed landing gear Thanks for all of that, Jack. I was planning on going to a 1.5 x .188 axle. Heat treating sounds like a very good idea. I have done that with small parts but how do you dp that on something this large? Also , did you up size your cross brace cables? Dick N. ________________________________ Message 12 ____________________________________ Time: 09:43:46 PM PST US From: "Dick Navratil" Subject: Re: Pietenpol-List: fixed landing gear --> Pietenpol-List message posted by: "Dick Navratil" Ditto here on the wheels. Dont get me wrong here guys on this bent axle. This was not a near disaster or anything. I just noticed more deflection than previous and one of the cables had stressed. Dick ----- Original Message ----- From: "Michael D Cuy" Subject: RE: Pietenpol-List: fixed landing gear > --> Pietenpol-List message posted by: Michael D Cuy > > > Dick-- my axle is about .20" thick and has survived some pretty rough > landings and a groud loop when my tailwheel shoe > failed. > > Mike C. > > PS-- the straight axle and wire wheels just look so go to me..I couldn't > even consider the split axle version with donut tires. > > >