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

jask 07-06-2022 05:13 PM

Antisplat ball bearing wheels
 
I spent the day Tues with Allan getting the wheel bearings installed. I have not installed the main wheels yet but the nose wheel spins extremely easy. I did the balance myself with a modified HF motorcycle balancer. This will do a lot to prevent the nose wheel from locking up and folding the gear. Pressure on the nose gear will not increase bearing preload as it does on the tapered bearings.

I am extremely pleased with his workmanship.

erich weaver 07-06-2022 06:16 PM

Quote:

Originally Posted by jask (Post 1618228)
This will do a lot to prevent the nose wheel from locking up and folding the gear.

Canít remember ever hearing about this happening before

jask 07-06-2022 07:06 PM

nose wheel
 
The design of the nose wheel system is not good. There is a 3/8 bolt that has two jobs. It serves as the axle and also adjusts the preload of the bearings. If enough pressure is placed on the nose wheel, the axle will bend and increase the preload on the tapered bearings. If the pressure is great enough, the bearings will lock up and the nose gear folds. IMO, it is the main cause of nose gear failures.

Roy Thoma 07-06-2022 07:45 PM

Poor nose wheel axel design
 
I agree that the nose wheel axel in RV's with the Matco wheel is poorly designed. Anti Splat bearings is one way to improve the design and minimize the rolling resistance.

I think the lease expensive way to reduce the rolling resistance of the nose wheel is the axel assembly from Matco. See http://www.matcomfg.com/AXLEASSEMBLY...dv-3657-1.html

Another way to minimize the rolling resistance, and to get rid of the tube that we use in a tubeless tire is to get the Beringer nose wheel. Aircraft Spruce is one source. See https://www.aircraftspruce.com/catal...oaAsSWEALw_wcB

I flew with the Matco wheel and axel for about 10 years before changing to the Beringer wheel.

On Soapbox: I've seen a handful of nose wheel flats using the cheap Van's tube in the tubeless type tire. My plane and sever others. It's my belief that tubes should not be used in tubeless tires and that doing so contribures to the tubes failing. The inside of the tire is rubbed away - because it is not designed to have a tube against it. Cord is exposed against the tube and it destroy's the tube. Off Soapbox.

Regards,

jask 07-06-2022 09:21 PM

Axle
 
I was not aware that Matco offered that axle. It solves the problem but you still have to pack bearings.

Walt 07-06-2022 09:27 PM

Grove also offers a tubeless wheel with an improved axle design.

jask 07-06-2022 09:33 PM

Axle
 
Does the set screw mess up the threads on the Matco axle?

lr172 07-07-2022 08:05 AM

Quote:

Originally Posted by erich weaver (Post 1618242)
Canít remember ever hearing about this happening before

+1

Thousands of RV's with the std bearing. SImply NO WAY a tight bearing will cause a nose gear leg to fold over.

Larry

BillL 07-07-2022 08:15 AM

A low rolling resistance will allow the nose wheel to rotate when flying. My -7a friend has this condition (anti-splat wheel) and it caused a primary vibration of the nose gear in flight due to wheel imbalance. The balance was fixed, but is everyone happy with the wheel always rotating in flight? That seems draggy.

Just asking . . . .

stringbender 07-07-2022 09:00 AM

vertical vibration
 
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?

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.

Bavafa 07-07-2022 01:11 PM

Quote:

Originally Posted by erich weaver (Post 1618242)
Canít remember ever hearing about this happening before

Plus one.

For those who wish to not have any resistance on the nose wheel, Matco sales a very nice axle for a very reasonable price (around $50).
I had installed it on multiple RV with great success.

lr172 07-07-2022 01:53 PM

Quote:

Originally Posted by jask (Post 1618423)
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.

It is. It is spring steel, so the oscillations you see are typical. People on the field are always telling me something is wrong with the nose gear after seeing me land or taxi. Leg needs to give on hard landings, so spring steel, struts or some sort of rubber doughnuts. Not saying it is a good or bad design only that it takes way more force than a locked up 4" rubber tire to bend it.


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