REFLECTOR: Shimmy on landing

[Dave Dent]

When you tighten the large nut under the fork make sure you are not just 
tightening the spacer in the bevel washers.  If you still have the thin 
washers get rid of them. The new thicker washers need no spacer. Also make 
sure you have no threads showing in your fork bushing.  If you have to many 
threads on the end of your strut you will have threads transfer into the 
bushing.  Now you no longer have a bushing to pivot on  but a jack screw 
that only wants to go up and down nut around the shaft.  So doing only 
allowing the tire to try and twist inside the fork.  So doing giving you a 
shake like you may never forget or till you change out your strut.

Also make sure you have the heavier fork.  If you have the light weight fork 
and you have had major shimmy you more then likely have cracked it.  Also 
check and see that the upper pivot bolt has not been bent.  Believe me it 
may be a grade eight bolt, it can bend and it will.  Also if you have a 
Matco wheel check to see if the 5/8" shaft through the wheel has not been 
bent.  Also if you have not installed the upper new pivot bushing supports 
do this.

Since I had my first shimmy problems I started trouble shooting nose gear 
problems.  What I have told you to check I made the changes.   Including a 
new strut, with less threads and changing the very week Matco wheel to a 
Cleveland type.  Much stronger all the way around.  I also removed all 
threads that extended below the fork nut after tightening to the 15lbs 
required.  I also cut 1/8" from off the face of the nut.  The reason for 
this was to move it further away of the top of the 6 ply tire.  If this is 
not done you will shave the top off on the first two or three landings.

Check all the above and if all done I would be checking the torque on the 
nut more often.  I check the nose fork pivot before each flight.  I hope 
this helps your and others.  I have had no problems with my  nose gear since 
I did all the above.

----- Original Message ----- 
From: "RICHARD J VANDERSTEEN" <rvandersteen at sbcglobal.net>
To: "Velocity Aicraft Owners and Builder list" <reflector at tvbf.org>
Sent: Saturday, April 08, 2006 8:49 PM
Subject: REFLECTOR: Shimmy on landing


> Any advice on what to check after a shimmy event on
> landing an XL-RG.
> _______________________________________________
> To change your email address, visit 
> http://www.tvbf.org/mailman/listinfo/reflector
>
> Visit the gallery!  www.tvbf.org/gallery
> user:pw = tvbf:jamaicangoose
> Check new archives: www.tvbf.org/pipermail
> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>