ATM "Stiction"

[Brad Davy <bdavy@fred.net>]

I finally had an opportunity to evaluate my homebuilt GEM last night. 
I've posted a couple messages about it, but in a nutshell, its a
multiple plywood wheel-metal roller driven reduction gear.  The RA axis
consists of a surplus 2" axle.  The thrust bearing is a swivel bearing
(5 inch diameter) from a local hardware store.  While the mount seems to
turn smoothly, it suffers from "stiction".  Torque builds up and then
lets loose, with the scope springing to the next position, obviously
unacceptable for photographic work.  I'm going to try greasing the
bearing pretty heavily to see if that helps eliminate the problem, but
I'm looking for other ideas.  The RA axis is mounted on two journal
bearings.  I've considered using ball bearings in pillow blocks to
combine axial and thrust bearings and eliminate the swivel, but I'm
attempting to do this without mortgaging the house.  I'm almost there,
but I'm running out of ideas.

Thanks!

-- 
Brad
bdavy@fred.net               http://www.fred.net/bdavy/home.html
bdavy@nox.cs.du.edu