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-   -   Antisplat ball bearing wheels (https://vansairforce.net/community/showthread.php?t=207838)

lr172 07-07-2022 09:15 AM

Quote:

Originally Posted by stringbender (Post 1618368)
I posted a week ago about having vertical (up and down) vibration on NLG tire, after inspection I found two flat spots. I removed the classic aero tire, put a replacement tire/tube from my hangar mate and flew it. It was worst...but the tire was 1/8'' out of round. I then order two new ones from Spruce, and the tire was true. I then talked to a EAA Mentor who installs a spacer inside the wheel, so to obtain a normal torque on the 3/8'' bolt. Not the 7-10 foot lbs. The "trick is" to make the spacer big enough that the bearings are free to move, roll freely. That is quite a task. I made several spacers and the grease drag on the bearing made it difficult to tell. Too big and the bearing would rotate on the outside spacer (not to be confused with the inside spacer that was manufactured). Too small and you don't get a torque up of the bolt.

The goal I had was to be able to rotate the tire with bearings greased "one full turn".

History; I purchased the aircraft 1 year ago, everything has been fine until a vertical vibration was felt. 80 flight hours and approx 100 landings. I did notice the original spacers had rotated which I think was from the original owners history, it leaves slight grooves in the Yoke.

Suggestions?
Comments?

Question; Does anyone have a internal spacer dimension?

Just buy the matco axle. It is under $100 and is adjustable to create the correct pre-load for ANY installation. It is the easiest fix for the issue you have.

Larry

jask 07-07-2022 10:32 AM

Quote:

Originally Posted by stringbender (Post 1618368)
I posted a week ago about having vertical (up and down) vibration on NLG tire, after inspection I found two flat spots. I removed the classic aero tire, put a replacement tire/tube from my hangar mate and flew it. It was worst...but the tire was 1/8'' out of round. I then order two new ones from Spruce, and the tire was true. I then talked to a EAA Mentor who installs a spacer inside the wheel, so to obtain a normal torque on the 3/8'' bolt. Not the 7-10 foot lbs. The "trick is" to make the spacer big enough that the bearings are free to move, roll freely. That is quite a task. I made several spacers and the grease drag on the bearing made it difficult to tell. Too big and the bearing would rotate on the outside spacer (not to be confused with the inside spacer that was manufactured). Too small and you don't get a torque up of the bolt.

The goal I had was to be able to rotate the tire with bearings greased "one full turn".

History; I purchased the aircraft 1 year ago, everything has been fine until a vertical vibration was felt. 80 flight hours and approx 100 landings. I did notice the original spacers had rotated which I think was from the original owners history, it leaves slight grooves in the Yoke.

Suggestions?
Comments?

Question; Does anyone have a internal spacer dimension?

I saw several examples of the bushings that had locked up and spun against the yoke. If those bushings lock up, it also means the bearings are locked up. A correctly sized spacer between the bushings would set the preload and do the same thing as the Matco axle.

I disagree that a locked nose wheel would "not fold the gear".

jask 07-07-2022 11:08 AM

Matco axle
 
Quote:

Originally Posted by lr172 (Post 1618372)
Just buy the matco axle. It is under $100 and is adjustable to create the correct pre-load for ANY installation. It is the easiest fix for the issue you have.

Larry


Do you have the Matco axle installed?

jask 07-07-2022 11:13 AM

Axle
 
Another solution is to replace the 3/8 bolt with a larger hard bolt.

jask 07-07-2022 11:44 AM

axle
 
Quote:

Originally Posted by jask (Post 1618398)
Another solution is to replace the 3/8 bolt with a larger hard bolt.

If you look at the Matco axle, that is effectively what they are doing. The 6061 spacer just makes the axle thicker. Just drill out the yoke and spacers and use a cad plated 1/2 bolt. That's the cheapest solution.

lr172 07-07-2022 11:46 AM

Quote:

Originally Posted by jask (Post 1618396)
Do you have the Matco axle installed?

Yes, on both my planes.

lr172 07-07-2022 11:48 AM

Quote:

Originally Posted by jask (Post 1618408)
If you look at the Matco axle, that is effectively what they are doing. The 6061 spacer just makes the axle thicker. Just drill out the yoke and spacers and use a cad plated 1/2 bolt. That's the cheapest solution.

No. The matco axle provides a threaded mechanism to set bearing pre-load SEPARATE from the torque on the axle bolt. It is NOT just a bigger axle bolt with spacers. In fact, it doesn't use spacers and uses the original 3/8 bolt.

Larry

lr172 07-07-2022 11:53 AM

Quote:

Originally Posted by jask (Post 1618391)
I saw several examples of the bushings that had locked up and spun against the yoke. If those bushings lock up, it also means the bearings are locked up. A correctly sized spacer between the bushings would set the preload and do the same thing as the Matco axle.

I disagree that a locked nose wheel would "not fold the gear".

If you believe the the NLG would permanently bend before the rubber tire broke traction with the asphalt, why would you even consider flying in one. Folded NLG = flipped plane. Not a lot of friction offered by a tiny 4" tire. Do you also feel that the MLG will fold over if you accidentally lock up the main tires via the brakes? If you trully believe these things, I am shocked you would fly in one. Do you really think a respected Engineer would design a leg that would fold before the tire broke traction? Dropping the nose wheel in a gopher hole at 50 MPH is a whole different matter when it comes to folding the NLG; Totally different energy profile.

RicoB 07-07-2022 12:28 PM

I got the antisplat mod recently and its great.

jask 07-07-2022 01:01 PM

Nose wheel
 
I was watching an RV6A landing a few months ago. I was 300 or 400 feet away but when the nose wheel touched down, probably at about 30 kts, there was a rapid oscillation of the gear fore and aft of several inches maybe about 6 times. The force to bend the nose gear must be huge.


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