Mailing List lml@lancaironline.net Message #38220
From: <Sky2high@aol.com>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] Aileron Vibration - Help
Date: Fri, 27 Oct 2006 00:01:16 -0400
To: <lml>
In a message dated 10/26/2006 10:36:01 P.M. Central Standard Time, kneefjes@cogeco.ca writes:
Has anyone out there with a L360 had problems with aileron vibration? 
 
 I have just completed my project and am very happy with all aspects of this airplane but I can't get rid of this buzz. It happens at most power settings/airspeeds and all control linkages/tubes are free from any rubbing/binding.  This is not a huge amount of vibration but I feel any amount only means excessive wear etc.
 
During first flight we noticed it so into the shop it went. I replaced all the bellcrank bearings because of minimal slop and that helped immensely but I still see some play within the aileron hinges.  Looking back to previous discussions, I see some have tried a modified hinge pin/insert.  Could anyone give me an update on how that has worked for them and also, any updates on solutions that have worked for you.
Kevin,
 
1. Hinge hole diameter in MS hinge material is 0.0930 +.005/-.000 and MS hinge material is .089 +/- .001.  The play right out of the box is 0.003 to .010.  A  0.0955" reamer can be used to remove burrs if necessary since hinges seem to be larger.  Stainless steel welding rod can be obtained that is 3/32 diameter (0.09375).  I use 3/32 SS rods and my hinges are tighter with no increase in friction and a great reduction in hinge play and lash.  If I clamp one aileron, the other one will move less than 1/2 under a mild push.
 
2. My ailerons are rigged so that both are slightly up.  This places a very small load on the system so that the ailerons are not floating in a neutral dead band subject to natural vibration.
 
Are you sure the elevators are not contributing to the buzz?

 
Scott Krueger AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL (KARR)

A man has got to know his limitations.
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