Recently I stumbled on a web page for a barn door tracker that was
driven by a micro controller in order to provide a variable drive
rate. Unfortunately I forgot to bookmark it and now after searching
with Google and looking through other barn door and ATM sites I still
can't find it.

I remember that the drive screw went through two delrin rods (one of
which was threaded and the other was the motor mount) in order to
provide pivots at both ends of the drive screw. The delrin rods were
in aluminum blocks with slotted screw holes so that the position of
the bearings on the boards could be adjusted to the correct distance
from the hinge. There was a switch that let the micro controller
recognize when the boards were in the closed position before the start
of a tracking session. All of the fabrication work was very nicely
done.

Does this sound familiar to anyone?

--
Brian Reynolds | "But in the new approach, as you know,
| the important thing is to understand
http://www.panix.com/~reynolds/ | what you're doing rather than to get
NAR# 54438 | the right answer." -- Tom Lehrer