Original Posted By: Jim Boyer
Here's my $.02 cents on the different landing gears. (and worth everypenny!)"Jenny gear" is significantly heavier due to that big 'ole axle, and one hasto devise some clever means to keep the axle from rotating if one usesbrakes. From all my reading of old newsletter back issues and FAA accidentreports, and my own experience this spring I believe the Jenny gear hasproven itself to be the stronger design. I do not believe it is easier tomake, on the contrary, I think it is one of the trickiest parts of the wholeproject. Welding up the split gear would be much easier in my opnion."split gear" (shouldn't really call it a cub gear because it predated thecub) is much lighter, easier to make and simpler to install brakes on.This gear also won't catch tall weeds or crops in an off field landing andflip one over as easily as the axle on the Jenny style will. Though LarryWilliams claims his Jenny gear axle saved him from nosing over in his offfield experience when he taxied into a hidden hole and the only thingkeeping the plane from going over was the axle catching on the edge of thehole.As beautify is in the eye of the beholder, I can't say which is prettier. Ilove the nostalgic look and strength of the Jenny gear, but I also love asplit type gear with big wheels like Don Emch's, and you see that a lot inold pictures. Bernard Pietenpol didn't build too many with the Jenny gear before he wentto the split type gear and never looked back, mainly because he was BIG intosaving weight, and he claimed the split axle didn't catch weeds as much inovergrown fields which they landed in a LOT.I'm using the Jenny gear because its' nostalgia and strength.Douwe________________________________________________________________________________Date: Tue, 3 Aug 2010 15:18:24 +0000 (UTC)
Pietenpol-List: landing gears
RE: Pietenpol-List: landing gears
Original Posted By: owner-pietenpol-list-server(at)matronics.com
Well said, Douwe. I agree completely with everything you said.One other consideration when making the Jenny style straight axle gear isthat from an engineering standpoint, it is a very inefficient design in thatthe bending moment in the axle is constant across the entire length of theaxle from bungee to bungee. What this means is that it does no good to tryto beef up the highly stressed area because the stress is essentiallyconstant all along the axle. That requires a pretty substantial wallthickness in the tubing, or heat treating to increase strength, or both. Ibroke my first axle in a hard forced landing. It was 1.5" diameter, .125"thick 4130. My new axle is 1.5" dia, .188" thick and heat treated to160,000 psi ultimate strength. Going to the thicker wall added nearly 4 lbsto the airplane.If I were to build another Pietenpol, I would do the split axle gear withwire wheels, as Don Emch did. It preserves most of the antique look whilesaving considerable weight and bother.Jack PhillipsNX899JPRaleigh, NC _____
Well said, Douwe. I agree completely with everything you said.One other consideration when making the Jenny style straight axle gear isthat from an engineering standpoint, it is a very inefficient design in thatthe bending moment in the axle is constant across the entire length of theaxle from bungee to bungee. What this means is that it does no good to tryto beef up the highly stressed area because the stress is essentiallyconstant all along the axle. That requires a pretty substantial wallthickness in the tubing, or heat treating to increase strength, or both. Ibroke my first axle in a hard forced landing. It was 1.5" diameter, .125"thick 4130. My new axle is 1.5" dia, .188" thick and heat treated to160,000 psi ultimate strength. Going to the thicker wall added nearly 4 lbsto the airplane.If I were to build another Pietenpol, I would do the split axle gear withwire wheels, as Don Emch did. It preserves most of the antique look whilesaving considerable weight and bother.Jack PhillipsNX899JPRaleigh, NC _____
Pietenpol-List: Re: landing gears
Original Posted By: "Don Emch"
Hi Oscar, I finally had time after getting back from Brodhead and Oshkosh to dig into this.Yup - your guru was right - my P-lead nut came off. The wire connector waswas still on the terminal, but was bouncing around on it not making good constantcontact. Used a 1/2 height nyloc nut and star washer - and instant gratification.Thanks!Lorin--------Lorin MillerWaiex N81YXGN-1 N30PPRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: landing gears
Hi Oscar, I finally had time after getting back from Brodhead and Oshkosh to dig into this.Yup - your guru was right - my P-lead nut came off. The wire connector waswas still on the terminal, but was bouncing around on it not making good constantcontact. Used a 1/2 height nyloc nut and star washer - and instant gratification.Thanks!Lorin--------Lorin MillerWaiex N81YXGN-1 N30PPRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: landing gears
Pietenpol-List: Re: landing gears
Original Posted By: "j_dunavin"
Just some thoughtsJohn wrote: > "it appeared to me that downwind to short final was more an arc rather than thesquared off pattern we were and still are required to fly, unless given a straightin approach".In a Biplane, I was taught to fly an arc to landing for visibility reasons. Illgrant you the Air Camper may not be quite as restricted but unless Im mistakenat an uncontrolled airfield there is no one to give a straight in approach(clearance?). To nit-pick, there isnt an FAR requiring a squared off patterneither its suggested in the AIM (and a good idea IMO) but it is not required.Gene wrote: > "I propose that we encourage our group to allow only known individuals to proptheir aircraft, and possibly add a forum on hand propping to the Saturday lineup,out in front of the aircraft with differing engines/setups as demonstrations".Group or no group, I cant imagine asking just some person to prop my plane. Notonly am I clueless whether this bozo knows how to prop a plane, but how is hegoing to communicate if he wants the ignition on or off. Theres more goingon than meets the eye (especially to a non-aviators eye).I like the idea of a forum on hand propping. It doesnt have to be fancy or formal,but even just sharing amongst ourselves about chocking or tying and techniqueswe use and letting anyone listen in is great. I had never hand-proppeda Model-A and since Im building one I wanted to experience it, so I approachedLarry Williams and explained my reasoning and he was kind enough to allow meto prop his Piet. Afterwards I felt silly for asking because it was straightforwardbut in truth Im glad I did.Id hate to see our group fill up with rules and regulations, but I understand thedesire for safety. I just start to wonder who will enforce the rules and whatwill the penalties be if I round off my base to final leg without being givena straight in approach.Read this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: landing gears
Just some thoughtsJohn wrote: > "it appeared to me that downwind to short final was more an arc rather than thesquared off pattern we were and still are required to fly, unless given a straightin approach".In a Biplane, I was taught to fly an arc to landing for visibility reasons. Illgrant you the Air Camper may not be quite as restricted but unless Im mistakenat an uncontrolled airfield there is no one to give a straight in approach(clearance?). To nit-pick, there isnt an FAR requiring a squared off patterneither its suggested in the AIM (and a good idea IMO) but it is not required.Gene wrote: > "I propose that we encourage our group to allow only known individuals to proptheir aircraft, and possibly add a forum on hand propping to the Saturday lineup,out in front of the aircraft with differing engines/setups as demonstrations".Group or no group, I cant imagine asking just some person to prop my plane. Notonly am I clueless whether this bozo knows how to prop a plane, but how is hegoing to communicate if he wants the ignition on or off. Theres more goingon than meets the eye (especially to a non-aviators eye).I like the idea of a forum on hand propping. It doesnt have to be fancy or formal,but even just sharing amongst ourselves about chocking or tying and techniqueswe use and letting anyone listen in is great. I had never hand-proppeda Model-A and since Im building one I wanted to experience it, so I approachedLarry Williams and explained my reasoning and he was kind enough to allow meto prop his Piet. Afterwards I felt silly for asking because it was straightforwardbut in truth Im glad I did.Id hate to see our group fill up with rules and regulations, but I understand thedesire for safety. I just start to wonder who will enforce the rules and whatwill the penalties be if I round off my base to final leg without being givena straight in approach.Read this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: landing gears
Re: Pietenpol-List: Re: landing gears
Original Posted By: "j_dunavin"
Joe,I don't know the weight of the steel gear but the Jenny style landing gear on NX18235 weighs 60 lbs. That weight includes wheels, axle and spreader bars, wooden struts, bungees and bracing cables. It does not include brakes as they are not installed.Dan Helspers comments about the wooden gear looking cooler is right on.......Greg Cardinal----- Original Message -----
Joe,I don't know the weight of the steel gear but the Jenny style landing gear on NX18235 weighs 60 lbs. That weight includes wheels, axle and spreader bars, wooden struts, bungees and bracing cables. It does not include brakes as they are not installed.Dan Helspers comments about the wooden gear looking cooler is right on.......Greg Cardinal----- Original Message -----