[carguy614]

I have seen a couple of builder sites where folks have installed lead shot as a counterweight in the nose of the wheel pant. Can't figure this one out. Can anyone shed some light???

All the best, and Happy Holidays...Chris

 

[jsharkey]

I have seen a couple of builder sites where folks have installed lead shot as a counterweight in the nose of the wheel pant. Can't figure this one out. Can anyone shed some light???

All the best, and Happy Holidays...Chris

Dynamic leg damper?
Jim Sharkey

 

[vlittle]

I did this, then removed it later. Made no difference, I don't get gear shimmy either way.

I also have the wooden leg stiffeners.

Saved 1.5 lbs in empty weight, too!

 

[carguy614]

shimmy damper??

So I guess this was an effort to reduce wheel shimmy, eh?? Hmmmm....Sounds like snake oil to me...but I could be wrong.(again)

Regards...Chris

 

[sprucemoose]

In theory, it balances the wheel pants fore and aft to reduce the tendency for the pant to oscillate, causing gear leg shimmy. Similar to the idea of balancing a tire (or prop.) Don't fully understand the physics involved, but the proof is in the pudding, because it made a noticeable difference.

Mine might be one of the websites you are referring to:

http://home.mindspring.com/~rv6/RV6site/wheel pants.htm

 

[longranger]

In theory, it balances the wheel pants fore and aft to reduce the tendency for the pant to oscillate, causing gear leg shimmy. Similar to the idea of balancing a tire (or prop.) Don't fully understand the physics involved, but the proof is in the pudding, because it made a noticeable difference.

Mine might be one of the websites you are referring to:

http://home.mindspring.com/~rv6/RV6site/wheel pants.htm

More similar to balancing an elevator. Just like the airplane itself, stability comes from having the center of gravity ahead of the center of pressure. Think of an arrow.

 

[az_gila]

Used in certified planes....

So I guess this was an effort to reduce wheel shimmy, eh?? Hmmmm....Sounds like snake oil to me...but I could be wrong.(again)

Regards...Chris

My Grumman Tiger comes with a weight in the nose of the main gear pants...

But the Tiger has a much more flexible mounting system, with swivels at the axle and a rubber bushing mount at the top of the pant. By comparison, the RV pants are much more "hard" mounted, and I would guess the weights would have less effect.

gil A

 

[Ron Lee]

Here is my view

Longranger got the aerodynamics right. (OK, aerodynamics is not the right word. Physics?, angular momentumicity?, mascons?) But the real question is do you need it?

I can look at a nose gear assembly when the pilot notes an issue and tell you if it is shimmy, a gear flexibility problem or wheel/tire out of balance/out of round condition.

Most likely you are having a wheel/tire out of balance/out of round problem IF you have the breakout force set correctly.

Since you may not be flying I suggest verifying that your nosewheel/tire is not out of round and is balanced. Adding a nose gear stiffener is probably a better preemptive measure than adding lead shot at this time.

Have someone who knows what to look for look at the tire in question from the front and side. Videotape it. It will be obvious.

 

[sprucemoose]

I don't think it has much to do with aerodynamics, since we are talking about 15-20 kts speed where the wind doesn't have much of an effect.

And, just to clarify, my experience is with the main gear on a 6 taildragger. I'm not sure what if any the effect would be on a nosewheel fairing.

 

[Warren Moore]

I agree with Ron Lee's comments. I had a shimmy on my rv4. I glassed in some lead shot to balance the wheel pant along the axle line. It did help some. But the real problem was flat spots on my aero-trainer tires...I messed up by leaving the plane in one spot too long while I finished it. Put new tires on, removed the lead shot....no problems now at all.

 

[gmcjetpilot]

Don't add weight if you don't have to

You have so much wheel pant hanging aft of the axial the nose lead balances it out. If it shimmies the aft CG of the pant causes the shimmy to be larger. The lead shot in the nose dampens it out, in theory. I'm with all of you, try to avoid lead shot and weight if you can.