Pietenpol-List: Axle thickness?

An archive of the Matronics Pietenpol Listserve.
Locked
matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Pietenpol-List: Re: Ruddder Horn Repair

Post by matronics »

Original Posted By: "aabreu"
The Rudder Horn on 6186L broke.- We removed it from the aircraft and made a repair... just in time for flying season.Here are some pictures.http://http://tinyurl.com/aqe27h3Andy Abreu KTDZ ________________________________________________________________________________Subject: Pietenpol-List: Re: Ruddder Horn Repair

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Pietenpol-List: Axle thickness?

Post by matronics »

Original Posted By: shad bell
Just wondering what everyone is using for axle thickness for straight gear piets?Mine is 1-1/2" x .120 wall chromolly and I can see it flexing just sittingthere.....i know somebody on here broke an axle and increased it to 3/16 wall......--------NX321LRFully AssembledTail assembly and ailerons covered and painted.Wings covered and primed, one paintedMitsubishi PoweredRead this topic online here:http://forums.matronics.com/viewtopic.php?p=399294#399294 ________________________________________________________________________________Date: Wed, 24 Apr 2013 12:09:01 -0700 (PDT)

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

> Pietenpol-List: Axle thickness?

Post by matronics »

Original Posted By:> rmdinfo(at)rmdbenders.com
That is interesting=2C I have the same size and it has a very noticable bow to it. Craig > Subject: Pietenpol-List: Axle thickness?

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

RE: Pietenpol-List: Axle thickness?

Post by matronics »

Original Posted By: owner-pietenpol-list-server(at)matronics.com
That would be me. My original axle was 1-1/2" OD, .120 wall. My new axleis 1-1/2" OD, .188 wall, heat treated after welding to 160,000 psi ultimatestrength.The thin wall axle is ok if you don't have brakes and the wheels are veryclose to the V-blocks of the undercarriage. The problem comes when brakesrequire moving the wheels further outboard, which dramatically increases themoment applied to the axle. Add a stress riser, such as a guide pin toprevent axle rotation, and you can find yourself in the same situation Idid.Jack PhillipsNX899JPSmith Mountain Lake, Virginia-----Original Message-----

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

RE: Pietenpol-List: Re: Axle thickness?

Post by matronics »

Original Posted By: owner-pietenpol-list-server(at)matronics.com
Yes. I had oxy-acetylene welded the pin into the axle, and probably had asmall crack there which caused enough of a stress concentration to weakenthe axle. But after it broke and I (belatedly) ran a stress analysis on thedesign I was surprised to see how highly loaded that configurtion is andconcluded that it was a very marginal design. On my new axle I had a professional welder TIG weld the pins, then sent thewhole assembly to Rex Heat Treating in Pennsylvania to be heat treated to160,000 psi (normalized 4130 is good for 90,000 psi). Of course heattreating does not increase stiffness, so it still has a slight bow but notapparent to the eye (as Jerry Dotson said, you can see the bow with astraightedge). The bow is significatnly less than it was with the .120"wall.Jack PhillipsNX899JPSmith Mountain Lake, Virginia-----Original Message-----

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Pietenpol-List: Re: Axle thickness?

Post by matronics »

Original Posted By: John Franklin

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

RE: Pietenpol-List: Re: Axle thickness?

Post by matronics »

Original Posted By: > jack(at)bedfordlandings.com
I need to replace my old axel as I proceed to rebuild the wood gear=2C So I should at Least buy the heavier wall axel? I do not have the money to heat treat etc. so I will just go heavy. How much more weight is the thicker wall? Craig

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

> Pietenpol-List: Re: Axle thickness?

Post by matronics »

Original Posted By: jorge lizarraga

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Pietenpol-List: Re: Axle thickness?

Post by matronics »

Original Posted By: Craig Aho
Hey Craig,Something to consider if you don't want to heat treat, is buying a tube alreadyin the state you want and then use a method that doesn't require welding on thetube.2RN has a 3/16 wall tube, but it has 1" solid inserts that go through the 1" IDbearings in the wheels (not sure of your setup). I imagine the 1" inserts (whichhave a 1/16 wall sleeve to make up the difference between 1 1/2OD, 1 1/8ID- 3/16 wall) do strengthen things up a bit more. Also has a free floating platewith the brake calipers. Anti rotation is via short cables so no weldingis required.It's been stressed enough to severely bend up a wheel with no ill effects on theaxle, so it's a proven system.Read this topic online here:http://forums.matronics.com/viewtopic.php?p=399359#399359 ________________________________________________________________________________

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

> Pietenpol-List: Re: Axle thickness?

Post by matronics »

Original Posted By:> n0kkj(at)yahoo.com
I will have to look at that setup. My wire wheel hubs are designed to slip on to the 1.5" axel. > Subject: Pietenpol-List: Re: Axle thickness?

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Post by matronics »

Original Posted By: Jim Boyer
Well, there's no reason the setup couldn't be the same, except the free floatingcaliper holder would be over the 1 1/2" axle. IF you wanted the extra strength (but I really think you wouldn't) you could stillslip in a short solid stub.I'll be in GA (where my plane is) in a week or so. If you want, I'll get somegood close up pics of the setup. Just let me know.Read this topic online here:http://forums.matronics.com/viewtopic.php?p=399366#399366 ________________________________________________________________________________Date: Thu, 25 Apr 2013 16:49:06 +0000 (UTC)

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Pietenpol-List: Re: Axle thickness?

Post by matronics »

Original Posted By: "Craig Aho"
Almost a 5 lb weight penalty...[quote="gcardinal(at)comcast.net"]1 1/2 X .120 = 1.770 lbs. per foot. 1 1/2 X .188 = 2.636 lbs. per foot. Greg Cardinal

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

> Pietenpol-List: Re: Axle thickness?

Post by matronics »

Original Posted By:> n0kkj(at)yahoo.com
Thank you tools=2C I would appreciate seeing your setup as I am having a bit of trouble visualizing. Thanks to all on this subject matter the discussion is helping me. I am currently working on the landing gear so it is totally pertinent. Craig > Subject: Pietenpol-List: Re: Axle thickness?

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

RE: Pietenpol-List: Re: Axle thickness?

Post by matronics »

Original Posted By: owner-pietenpol-list-server(at)matronics.com
When I rebuilt my Pietenpol after the accident, it gained 5.5 lbs. Inaddition to the axle weight added, I added some weight in the tailrebuilding the broken lower right longeron, but I saved some weight bychanging from a leaf spring tailwheel to the BHP swinging A-Arm type. Myaxle is 7 feet long, so I added 6.06 lbs to the axle.Jack PhillipsNX899JPSmith Mountain Lake, Virginia-----Original Message-----

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Re: Pietenpol-List: Re: Axle thickness?

Post by matronics »

Original Posted By: Craig Aho
Mine are 1 1/2" bronze flange bearings I mademyself. The wheel needed some creativemachining as my lathe/mill isn't big enoughto chuck a 19" wheel. I made an extensionfor the outer side to place the bearings anextra 1 1/2" further apart. I did everything I could to keep the wheel as close as possibleto the bungies thus reducing the bendingmoment on the axle. The only things notmounted on the airframe are the wing panelsand fabric. The engine is 260 lb. There is nobending on the axle evident at all. It is 1 1/2"with 0.125 wall. I have purposely designedmy brake system to not require anythingwelded to the axle. Will the 120 odd lb ofwing panels make the axle bend? I don'tknow. Hopefully I will find out by the Fall.All in good time.Clif ----- Original Message -----

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

> RE: Pietenpol-List: Re: Axle thickness?

Post by matronics »

Original Posted By:> owner-pietenpol-list-server(at)matronics.com
> gs.com>> > Yes. I had oxy-acetylene welded the pin into the axle=2C and probably had a> small crack there which caused enough of a stress concentration to weaken> the axle. But after it broke and I (belatedly) ran a stress analysis on the> design I was surprised to see how highly loaded that configurtion is and> concluded that it was a very marginal design. > > On my new axle I had a professional welder TIG weld the pins=2C then sent the> whole assembly to Rex Heat Treating in Pennsylvania to be heat treated to> 160=2C000 psi (normalized 4130 is good for 90=2C000 psi). Of course heat> treating does not increase stiffness=2C so it still has a slight bow but not> apparent to the eye (as Jerry Dotson said=2C you can see the bow with a> straightedge). The bow is significatnly less than it was with the .120"> wall.> > Jack Phillips> NX899JP> Smith Mountain Lake=2C Virginia> > -----Original Message-----

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Pietenpol-List: Re: Axle thickness?

Post by matronics »

Original Posted By: "tools"
> To: pietenpol-list(at)matronics.com> > > Hey Craig=2C> > Something to consider if you don't want to heat treat=2C is buying a tube already in the state you want and then use a method that doesn't require welding on the tube.> > 2RN has a 3/16 wall tube=2C but it has 1" solid inserts that go through the 1" ID bearings in the wheels (not sure of your setup). I imagine the 1" inserts (which have a 1/16 wall sleeve to make up the difference between 1 1/2OD=2C 1 1/8ID - 3/16 wall) do strengthen things up a bit more. Also has a free floating plate with the brake calipers. Anti rotation is via short cables so no welding is required.> > It's been stressed enough to severely bend up a wheel with no ill effects on the axle=2C so it's a proven system.> > > > > Read this topic online here:> > http://forums.matronics.com/viewtopic.php?p=399359#399359> > > > > > > ============================================> > > ________________________________________________________________________________Subject: Pietenpol-List: Re: Axle thickness?

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

> RE: Pietenpol-List: Re: Axle thickness?

Post by matronics »

Original Posted By:> owner-pietenpol-list-server(at)matronics.com
> gs.com> > > Yes. I had oxy-acetylene welded the pin into the axle, and probably had a> small crack there which caused enough of a stress concentration to weaken> the axle. But after it broke and I (belatedly) ran a stress analysis on the > design I was surprised to see how highly loaded that configurtion is and> concluded that it was a very marginal design. > > On my new axle I had a professional welder TIG weld the pins, then sent the > whole assembly to Rex Heat Treating in Pennsylvania to be heat treated to> 160,000 psi (normalized 4130 is good for 90,000 psi). Of course heat > treating does not increase stiffness, so it still has a slight bow but not > apparent to the eye (as Jerry Dotson said, you can see the bow with a > straightedge). The bow is significatnly less than it was with the .120"> wall. > > Jack Phillips > NX899JP > Smith Mountain Lake, Virginia > > -----Original Message-----

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

> RE: Re: Axle thickness?

Post by matronics »

Original Posted By: "Cuy, Michael D. (GRC-RXD0)[Vantage Partners, LLC]"
> > > Yes. I had oxy-acetylene welded the pin into the axle, and probably had a> small crack there which caused enough of a stress concentration to weaken> the axle. But after it broke and I (belatedly) ran a stress analysis on the> design I was surprised to see how highly loaded that configurtion is and> concluded that it was a very marginal design. > > On my new axle I had a professional welder TIG weld the pins, then sent the> whole assembly to Rex Heat Treating in Pennsylvania to be heat treated to> 160,000 psi (normalized 4130 is good for 90,000 psi). Of course heat> treating does not increase stiffness, so it still has a slight bow but not> apparent to the eye (as Jerry Dotson said, you can see the bow with a> straightedge). The bow is significatnly less than it was with the .120"> wall.> > Jack Phillips> NX899JP> Smith Mountain Lake, Virginia> > ----------NX321LRFully AssembledTail assembly and ailerons covered and painted.Wings covered and primed, one paintedMitsubishi PoweredRead this topic online here:http://forums.matronics.com/viewtopic.php?p=399381#399381 ________________________________________________________________________________

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

Post by matronics »

Original Posted By: "Jack Phillips"
> To: pietenpol-list(at)matronics.com> > > Well=2C there's no reason the setup couldn't be the same=2C except the free floating caliper holder would be over the 1 1/2" axle. > > IF you wanted the extra strength (but I really think you wouldn't) you could still slip in a short solid stub.> > I'll be in GA (where my plane is) in a week or so. If you want=2C I'll get some good close up pics of the setup. Just let me know.> > > > > Read this topic online here:> > http://forums.matronics.com/viewtopic.php?p=399366#399366> > > > > > > ============================================> > > ________________________________________________________________________________

matronics
Posts: 81779
Joined: Sat Mar 18, 2017 8:29 am

> Pietenpol-List: Re: Axle thickness?

Post by matronics »

Original Posted By: "Clif Dawson"
> To: pietenpol-list(at)matronics.com > > > Hey Craig, > > Something to consider if you don't want to heat treat, is buying a tube already in the state you want and then use a method that doesn't require welding on the tube. > > 2RN has a 3/16 wall tube, but it has 1" solid inserts that go through the 1" ID bearings in the wheels (not sure of your setup). I imagine the 1" inserts (which have a 1/16 wall sleeve to make up the difference between 1 1/2OD, 1 1/8ID - 3/16 wall) do strengthen things up a bit more. Also has a free floating plate with the brake calipers. Anti rotation is via short cables so no welding is required. > > It's been stressed enough to severely bend up a wheel with no ill effects on the axle, so it's a proven system. > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=399359#399359 > > > > > > <============= > > > No virus found in this message. Checked by AVG - www.avg.com04/25/13 ________________________________________________________________________________

Locked