Weld-On Axles

[lsa140]

Does anyone know of a source for ground and threaded 1-1/4 axles with 16tpi? Aircraft Spruce sells 1-1/4 x 12tpi. Both the plans and Matco spec 16tpi.

[stinger]

Plans TPI or Matco Tpi makes no difference . You only need a matching set, meaning that the axle and nut match. Stinger

[lsa140]

I'm sure either one would work. George at Matco recommended going with 16tpi for more accurate adjustment of the preload and use of their machined nut/washer combo to help hold the bearing seal face. Did you cut your threads on a lathe? I'm wondering if a die would work. It may be a challenge to get the threads full depth for their entire length. I could order the ground axles and rethread.

[marcusofcotton]

You might try giving Wick's a call. Their listings are messed up, I was able to get the 1-1/2"x16 from them even though it's listed as 12 tpi. You'd think they would straighten that out when it's pointed out to them. Good folks to deal with though.

[lsa140]

Good idea, I'll give both them and spruce a call. Spruce shows 1-1/4 x 12tpi and 1-1/2 x 16tpi.

[Clint B]

I've always gotten my axels from wag aero 20$ a piece for the 1.25" x 12 tpi. I didn't realize until reading this thread that your supposed to have a nut with a washer to support the bearing seal. There's well over 200 hours on my old cub with the Matco wheels on it and it's never been an issue not having them.

[lsa140]

I don't have any experience with Matco wheels/brakes yet and am still trying to understand what is required or preferred for axle setup.

It sounds like the seals Matco use produce enough drag to spin the entire bearing/seal on the axle. Axle preload is required to prevent the bearings/seals from spinning. In addition to preload, a larger diameter surface pressing against the bearing seal, and fixed in rotation helps keep the sealed bearings from spinning.

If I understand George from Matco correctly, an 1-1/4 axle with 1-1/2 OD sleeve/bearing stop works. (as shown on plans - standard weld on axle type) A bearing stop with a machined radius (as seen on their machined bolt on axles) that engages the inner bearing edge radius is better. (better secures bearing from rotation on axles/holds preload longer) A larger fixed surface actually engaging the surface of the seal helps hold the bearing and preload the best. Matco also recommends their 1-1/4 x 16tpi nut, with integrated washer to engage the bearing seal.

I suspect a standard cub type welded axle and 12tpi pinned nut with proper preload works fine? It sounds like this is what you had Clint B?

Mark Goldberg how is your LSA setup?

[Clint B]

The 12 TPI axles are what I used. Finer threads would be nice, but it has never been a problem.

[lsa140]

I went ahead and ordered Aircraft Spruce's 1-1/4 x 12tpi axles. They come 12" long, which gives me some length to play with. I also ordered an 1-1/4 x 16 tpi thread cutting die from eBay. I'll attempt cutting the 16tpi with the die on the unthreaded end. Not sure what kind of quality I can get with the die, but if it doesn't work out I will cut it off and use the 12tpi end.