Wheel Vibration at Low Speed

[ArVeeNiner]

I had a similar issue. First off, my mains were worn so I got some retreads.

Then, I got one of these cheap balancers and some stick on weights:

http://t.harborfreight.com/motorcycl...and-98488.html

I ended up using some Amazing Goop on the weights just to make sure they stayed put.

Then, I took my drill motor and chucked up a sanding disk I found deep in my toolbox. Next, as a double check, I spun up the tire mega fast using the edge of the disk on the tire. If the tire didn't do a dance, I called it good.

I slapped them back on, problem solved.

[Dustyone]

Hi Scott,

Another place to check is the gear retaining bolt at the top of the gear tower.

The plans call for only one washer and then torque. I have seen it twice now on RV-10's where the nut bottoms out on the thread allowing the gear to rotate a bit back and forth in the tower . Adding another washer and re-torquing reduced shimmy on that wheel.

Just another data point.

Cheers,

[istrumit]

Originally Posted by Dustyone

Hi Scott,

Another place to check is the gear retaining bolt at the top of the gear tower.

The plans call for only one washer and then torque. I have seen it twice now on RV-10's where the nut bottoms out on the thread allowing the gear to rotate a bit back and forth in the tower . Adding another washer and re-torquing reduced shimmy on that wheel.

Just another data point.

Cheers,

Could I get a pick of that ? I am having trouble understanding that location since I did not build myself. Also, thank you, I am always interested in other ideas.

[Dustyone]

Hi Scott,

Sorry, I do not have a picture.

You just remove the front seat and then the cover plate that covers the seat support frame.You will then have access to the top of the gear tower.

The way the bolt is installed means that the thread is facing down so that when builders torque that bolt,it is not so obvious that the nut has bottomed on the thread and not pulled up against the gear tower.

If the bolt has bottomed out and the gear leg and frame was reamed a touch oversized,the gear will be able to be rocked left and right.

Just something else to check,

Cheers,

[istrumit]

OK...I will try that.

I suppose, since I will be jacking it up to check the tire balance anyway, then, if there is a loose bolt as you mentioned, I should be able to move the leg back and forth by force once its off the ground ?

[Tim Lewis]

I had a similar problem at 30 knots or so. Balancing didn't help much, neither did stiffening the wheel pant mount. I fabricated and attached wooden shimmy dampers on the back side of the main gear legs, which solved the problem. My shimmy dampers are very similar to those described in the RV 6A fairing plans.

[istrumit]

If anyone on this thread has a jack stand they have built/bought or knows of one, and they are don't use it anymore, please let me know.

I'd be more than happy to purchase it and it and pay for shipping.

[lr172]

Originally Posted by istrumit

If anyone on this thread has a jack stand they have built/bought or knows of one, and they are don't use it anymore, please let me know.

I'd be more than happy to purchase it and it and pay for shipping.

I bought the larger hydraulic ram (made for their cherry picker, but with a flat base) from HF for $35. I put a piece of wood between it and the fuselage (right below the spar carry-through) and it lifts the wheel nicely. Not perfect, but cheap. I have also used a car jack by putting a worm gear clamp on the gear leg (a suggestion from the archives here).

Larry

[istrumit]

Originally Posted by lr172

I bought the larger hydraulic ram (made for their cherry picker, but with a flat base) from HF for $35. I put a piece of wood between it and the fuselage (right below the spar carry-through) and it lifts the wheel nicely. Not perfect, but cheap. I have also used a car jack by putting a worm gear clamp on the gear leg (a suggestion from the archives here).

Larry

Are you describing something like this ?

http://www.harborfreight.com/3-ton-s...ack-36468.html

[lr172]

Originally Posted by istrumit

Are you describing something like this ?

http://www.harborfreight.com/3-ton-s...ack-36468.html

That's the one. Some have built a base for it to give it more stability, I just use it as is and am very careful. It is not very stable, but if you block 2 of the three tires it is managable. Some have also modified it to lift at the wing by making a mount that goes in the tie down threads.

Post #6 here wil give you an idea for using a smaller bottle jack or traditional car jack:

http://www.vansairforce.com/communit...clamp+gear+leg

Larry