Jack,

 

OK, I've got the mental picture now.

 

Note the pivot point movement arcs in the diagram (my compass wasn't big enough for the actuator arm).

 

 

Assuming the actuator is locked open from gear down hydraulic pressure, the connections are tight and the hinge is tight (free of slop), door lateral wobble requires the bell crank pivot point to move upward and inward.  Note that a much higher ratio of inward movement to upward movement.  If the actuator is rigid and there is no slop at the rod end or the actuator bolted up end, upward movement is limited (and thus so is lateral door movement).

 

However, if the hinge is loose then the door can wobble.  I originally pop riveted (per instructions) the fuselage hinge part thru the imbedded aluminum.  At about 200 hours several of the fwd rivets had disintegrated and they were replaced with bolts.  (Hmmmm, I must go look but I think I also replaced the left fuselage hinge. I do use 3/32" SS welding rod for pins.

 

The main cause of the wobble is prop airflow (what prop are you using?).  If you would taxi without the prop turning, the problem would be solved.

 

I think everyone has this problem to some extent and minimization occurs by reducing the slop by tightening the bearing bolt and perhaps using a precision -A bolt at the actuator belly pan attach end (check for slop there), but especially in the hinge.

 

Scott

 

Inner gear doors, on Lancair 360:
Thanks Scott for reply.
The inner gear doors close okay.   Problem is as they hang they really vibrate during taxi and probably with gear extended too (but havn't checked in air yet).
The motion as I taxi looks like they will self destruct one day!
There really isn't any "hard point" holding the extended actuator end (gear down, on ground) from moving up and down just enough to allow that motion to translate to lateral vibration of the inner gear door itself.
 
Jack Addison
N360JS
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