May 23rd, 2002

To be able to use the existing rudder pedal pushrod mechanism in the F-15,
I had to come up with a way of connecting the whole assembly to a potentiometer
that could be used to input rudder pedal position to the flight simulator.

Calling on my previous experience doing control hook-ups in R/C airplanes, I
came up with a method that worked so well, it's used for nearly all the flight
controls in the simulator.

The picture below shows the genesis of the whole process.  The tiny little
black things are threaded mount balls that are used frequently in connecting
up servos to controls in R/C airplane (or boat, etc).  I drilled a 1/16" inch
hole in the top center of a 1/4" diameter bolt and then used an industrial
epoxy (JB Weld) to fix the ball atop the bolt.  There are two bolts shown 
here because I was doing the same thing for the aileron control at the time.

Here you can see the bolts setting up.  You need to make sure that none of the
epoxy spreads and changes the shape of the ball.

Here's the result.  The bolt was too long (I used what I had handy) so a 
spacer had to be installed, but it has worked out very well.  The nylon cup
assembly screws onto a 2-56 threaded music wire rod and then snaps over the
ball link.  It's a very smooth and non-binding assembly.

This is the other end of the connection.  I used a 100K Ohm slide pot with an
infinitely adjustable servo link to attach the pushrod to the pot arm.
I use this same setup for all the flight controls & toe-brakes in the sim.
All of the slide pots are mounted upside down so that dirt & debris won't 
foul up the contacts inside.  The only exception is the toe-brake assembly
but I've got a special built cover for that and that should keep them reasonably
clear of grime.

Here's a shot that shows both ends of the rudder pedal pot linkage.  The 
brown conduit you can see is the original air conditioning ducting.

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