Re: AP900 Dec backlash - more help required

Roland Christen

In a message dated 4/24/2007 10:10:02 PM Central Daylight Time, writes:

I can't get to the locking screw on the motor shaft through this side
cover to check it's tightness and can't even see the locking screws on
the other gear shafts.
There is only one locking screw, and that is on the last spur gear on the
worm itself. The other gears all run free on their pinions. You can remove the
largest gear in the train (use a normal srew driver to unscrew the shoulder
screw). Once you remove this gear, you can see the underlying pinion gear which is
attached to the worm. This gear has a small set screw on the side, and this
set screw must be tightened - it also must be centered on the flat, otherwise
it will probably loosen on you. If you cannot follow this, please call AP and
talk to Wally. He will guide you step by step in this procedure.

By the way, I do not know what you mean by "jumping", but it could be that
you have dialed in some backlash compensation on your keypad. Go into the setup
procedure and put 0 for backlash in both RA and Dec axes. This will eliminate
any motions that you may not be familiar with, and will aid in your
visualization of what needs to happen when reversing the RA and Dec axis.


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