Axle installation (split-axle)

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PoconoJohn
Posts: 165
Joined: Tue Jan 14, 2020 9:07 pm

Axle installation (split-axle)

Post by PoconoJohn »

From the many photos I've seen, it appears the prevailing method is to cut away the bottom of the V and fit the axle there.

Is it actually the axle there, or is it a slightly larger tube with the axle inserted? I'll put the rim on to see how much axle needs to extend from the V. The axle is 1.5" X 12" (WELD-ON 600 X 6).

After axle's are welded on, I'll work on the cross/shock tubes.

As always, I appreciate your help.

John C
jeffreyK
Posts: 43
Joined: Wed Jan 15, 2020 9:41 pm

Re: Axle installation (split-axle)

Post by jeffreyK »

John,
I recently completed my gear and I also had many questions and challenges regarding the build. I have been to Brodhead twice and have many pictures of the gear on multiple Piets. There is a fair amount of variation which didn't help me too much in deciding what to do. I had initially planned on doing what you propose, that being to cut out the 'V' and weld it to the builders axle. I ended up cutting out the 'V' but welding it to a piece of axle with a mounting plate for a factory axle and wheels. There is a picture of my gear in the Piet forum as well as the last newsletter. Here are a few things for you to think about in the decisions regarding this aspect of your build:
Welding to the axle as you propose will give you no ability to adjust for toe in or toe out once welded on. You will have some latitude to adjust camber if you have bearings that screw onto your shock struts. Mounting a bolt on axle to a welded on segment of axle will allow you to correct for toe in/out with the proper spacers if needed.
I found cutting the 'V' properly to be a real challenge. I made a couple of V's for practice. You can find templates for any size pipe to pipe transition however I couldn't find any for a 'V' to a straight pipe and had to work it out custom on my practice V's.
The gear legs are 1-3/8" tube. The builders axle is 1-1/2" tube and according to the plans they are cut at 60 and 70 degrees respectively. I'd love to hear how someone made two simple cuts like that and had both ends lining up properly!
There are no brakes accounted for in the plans so if you plan on brakes you will be modifying the plans to accommodate them. This also was a factor in my decision to mount a factory axle that accepts the brake caliper in the proper position for the wheel assembly.
A final note worth mentioning; Mr. Pietenpol moved the position of his gear towards the leading edge in later models. Refer to William Wynne's Weight and Balance manual for details about this. Changing the position of the gear is going to alter the lengths and angles of the gear legs from that in the plans. Another fine mess to sort out!
I hope this helps you out a bit on your gear build and good luck with it.
Jeffrey K
PoconoJohn
Posts: 165
Joined: Tue Jan 14, 2020 9:07 pm

Re: Axle installation (split-axle)

Post by PoconoJohn »

Thank you Jeffrey for all that information. It DOES help. After using a mock up with plans built V's, I saw the V tip was 19" from the firewall. I reviewed the info (Bernard's comments) on West Coast Piet along with William Wynne's weight & balance info (and even spoke with him). So now the tip of the V (axle area) is about 15" from the firewall. One problem addressed.

Lot's to think about with the axle. The last newsletter is on my coffee table. I'll have to find a few minutes to check it out. I'll definitely consider the toe-in/out aspect of this. And I will have brakes (most likely hydraulic).

Thanks again!

John C

My landing gear photos: https://imageevent.com/hatz/piet/landinggear
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Richard Roller
Posts: 240
Joined: Mon May 22, 2017 11:14 am
Location: Olathe, Ks.

Re: Axle installation (split-axle)

Post by Richard Roller »

John. I have Ken Perkins Piet, N34KP. Ken built lots of steel parts for other builders while he was still alive. For his landing gear he built a fixture to hold the gear V's and the axles in position while welding. I don't have a picture of the fixture, but I'll try to explain how it worked. The upper part of the fixture held the V's as they would be installed on the a/c. the lower end held the axles in position as they would be on the a/c in the three-point attitude for his a/c. His Piet originally had no brakes. Later mods of the fixture would allow for different fore and aft axles positions for a/c with brakes. One feature of the fixture was a tube that ran completely through both axles to keep the axles true to each other as they were being fitted and welded. I do have pictures I took, while modifying the a/c to have brakes, that show the gear V's and axles where they meet.
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PoconoJohn
Posts: 165
Joined: Tue Jan 14, 2020 9:07 pm

Re: Axle installation (split-axle)

Post by PoconoJohn »

Thank you Richard. I have a metal pipe running perpendicular to the longitudinal axis with the plane on its back. The V's were welded in a jig after I determined the correct lengths and angle based on information at the West Coast Piet site. The V's were hung on that metal pipe and I finished welding the areas at the gear fittings.

So I'm thinking about the post from Jeffrey (Jeff, saw the newsletter. You sure did a lot in 2= years! It'll take me that long just to do the wings).

If I could figure out how to cut the V's, I could use the metal pipe to keep the axles true to each other.

I continue to think about this. Thanks for posting those photos. Looks like the axle is connected to tubing.

John C
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