From: "Marvin Kaye" <marv@lancaironline.net>
Subject: Re: stiff ailerons
To: lml
Date: Thu, 06 May 2004 14:36:17 -0400
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Posted for "Robert Overmars" <robert.overmars@tiscali.it>:

Jack,

first things first, disconnect the long aileron pushrod from the outboard 
bellcrank. Then move the aileron through it's range of travel. The aileron 
should move with vitually NO force and be sufficiently free that it returns to 
the neutral balanced position of it's own accord. 

Probably it doesn't and this has happened because the centre and outboard 
bearing blocks are bolted to the inboard faces  of their respective mounts 
whereas the inboard bearing block is bolted to the outboard face of it's 
mount. When your aeroplane was painted almost certainly the aileron cove  and 
bearing block mounts were sprayed with paint which has had the effect of 
displacing the inboard bearing block  outboard, whereas the centre and 
outboard bearing blocks are displaced inboard by the thickness of the paint. 

With the aileron bearings being nothing more than truncated balls (attached 
and fixed to the aileron by the fork, the second part of the hinge) in the 
bearing housings it only takes a very slight displacement of the bearing 
blocks inboard or outboard for the balls  to start binding against their 
bearing housings. The axial freeplay before the ball starts binding against 
it's housing is only a few thousandths of a inch. If the bearing block mounts 
are painted there's more than enough thickness of paint to displace the 
bearing blocks so that the centre balls are forced with considerable force 
against their respective housings which makes the aileron then very stiff to 
move. I've seen this happen to the point that the autopilot roll control servo 
struggles to move the aileron.

A solution to this: move the bearing housing in it's bearing block. This can 
be quite easily done with a little fine threaded G clamp and little ingenuity 
(you figure it out). It's fiddly work but when you finally have the balls 
centred in their respective housings with the aileron hinge bolts tightened 
  you will have your aileron  wonderfully free such that it should return to 
it's balanced position and you should be able to blow on the aileron trailing 
edge to displace the aileron which should then cycle up and down a few times 
before settling in the balanced position.


Another place where there is often binding is the bearings for the control arm 
torque tube. With pressurisation the fuselage wants to change shape and then 
you have a situation where the front and rear bearing block s are displaced 
relative to each other causing the  centre balls which are bolted to the 
torque  tube to bind against their housings. This is in my opinion a case of 
not unusual poor Lancair design, a solution would be to have either the the 
front or the rear bearing ball free to move axially on the torque tube.

For starters I hope this helps.

Ciao,

Roberto d'Italia