Nosewheel Shimmy Video

[ZU-RVZ]

Hi All,

A year or two ago there was a fascinating video taken of an 'A' model nosewheel shimmy.

I think it was discussed in this thread
http://www.vansairforce.com/communit...nosegear+video

I have found a few others but none as 'bad' as the one in the video.

The link in the discussion is now dead. Does anyone have a new link or a copy of the video for me?

[L.Adamson]

I remember that video....

Just so you know, my 6A suffered that type of shimmy on it's very first landing (last Sept.). I let the nose down to quick, and the nose wheel nut needed to be torqued a bit more, as they loosen when new.

I'm now 91 hrs past that, and haven't had a landing shimmy since.

L.Adamson

[ZU-RVZ]

Any more takers?

[GrayHawk]

I made a copy of one video from about this timeframe. I'm not sure if it is the one you mention as this one shows fore & aft oscillation of the nosegear spar and very little shimmy or left to right motion of the actual nosewheel.

If interested I'll put it up somewhere.

[rvator51]

Here is one I posted back in 2006.

Nosegear shimmy

[DanH]

Clearly the fore and aft oscillation has nothing to do with fork nut preload.

I'm curious about a detail. Can someone post a few photos of a 7A engine mount and landing gear strut sans engine?

[GrayHawk]

Originally Posted by rvator51

Here is one I posted back in 2006.

Nosegear shimmy

That's the same one I have a copy of.

For the fore & aft oscillation shown, important info would be what type of nose wheel installed, whether there is a 'spacer' between the bearings on the axle bolt, torque on the axle bolt, rolling friction, etc.

[DanH]

Originally Posted by GrayHawk

For the fore & aft oscillation shown, important info would be what type of nose wheel installed, whether there is a 'spacer' between the bearings on the axle bolt, torque on the axle bolt, rolling friction, etc.

None of those things matter if the wheel/tire assembly is truly round, and if the there is no variation is rolling resistance with each revolution.

[Rick6a]

Originally Posted by DanH

....I'm curious about a detail. Can someone post a few photos of a 7A engine mount and landing gear strut sans engine?

Dan,

I don't know if these photos of the engine mount fitted to my -6A can help satisfy your curiosity. I suspect this engine mount is very similar in design to the -7 series nevertheless, the shimmy condition has been known to occur in the -6 series too.

[DanH]

Thanks Rick. I was thinking abut truss stiffness for the nose gear tube. Easy to make a structure strong enough, but sometimes difficult to make it stiff enough.