RE: REFLECTOR: front bearing questions

["SANCHEZ, MERRI J. (JSC-EC)" <merri.j.sanchez1@jsc.nasa.gov>]

I tend to lean toward a retainer as an intermediate step (doesn't address
total bracket failure, but helps to beef it some).  We built one out of
about $2 worth of 1/4" aluminum stock (yes it was overkill).  It is football
shaped with a hole for the rod.  A step is milled out for the bearing to fit
into (not necessary but prettier), and the original screw hole locations are
used into the bracket with structural screws.  It would be very easy for
anyone to duplicate this with about an hour's worth of work (less if you
don't mill a step).  I'd be glad to send dimensions out if anyone is
interested.

Merri Sanchez


> ----------
> From: 	Duane Swing[SMTP:DuaneS@velocityaircraft.com]
> Sent: 	Friday, January 08, 1999 10:03 AM
> To: 	reflector@awpi.com
> Subject: 	REFLECTOR: front bearing questions
> 
> To all Reflectorites:
>    Scott and I have been looking at the front bearing support and are
> working on a solution.  One of the problems that any wide area washer
> type retainer or the reversal of the bearing in the holder, or even the
> replacement of the countersink screws with standard flat head screws, is
> that unless the control stick is restricted from being pulled back
> further than the full down elevator will allow (26 degrees) the
> possibility of a total bearing failure or the attach aluminum bracket
> breaking as a result of constant flexing is still an issue.  It would be
> my initial thought that the control stick full aft movement should be
> restricted by placing an aluminum stop on the keel where the control
> stick would normally contact the aft end of the control stick hole when
> fully deflected.  On all the airplanes we have built, the total
> available movement of the control stick was always determined by the
> control stick contacting the fiberglass keel   once the 26 degree down
> elevator was reached. This does not eliminate all the loads on the
> bearing but does prevent "excessive" loads as a result of the elevator
> reaching it's maximum 26 degrees with still another 5 degrees or so of
> stick travel available to the pilot.  This added pressure is what can
> cause the bearing, attach bracket or screws to fail in time.
>    This is at this time just some thoughts on the subject.  We will
> continue to monitor the Reflector for answers and solutions to this
> problem.  
>    Sincerely,  Duane Swing  Velocity Inc.
>