ATM DEC-stepper on mount or tube?

[bsorheim@sn.no (Bjørn Sørheim)]

Clear skies,

I am currently mounting the steppers on the two axis of my ATM equatorial
GEM. In R.A. I have a 11" pulley on the shaft. The stepper is mounted
on an aluminum arm down to the side - it seems to work fine.
On the _DEC_ axis I had planned to do similarly, with the pulley on
the DEC shaft and the motor on an arm extended up from the polar axis
direction. 
Thinking a bit more about it seems to me that this arm would maybe be
in the way while observing, and also it does not look so elegant.
I also have to employ a machinist for making a custom round plate for
fastening the pulley to the shaft, and some other small obstacles.

A simpler solution would then be to mount the stepper underneath the 
craddle-plate (made of wood), and the pulley on the DEC-assembly flange.
In this solution, the arm is avoided and the arrangment is much more
compact, look nicer and is not in the way.
In this way the stepper drives it self around with the craddle and tube,
and the pulley is stationary.

What I wonder about is if this is a usual solution (I have not personaly
seen many ATM telescopes of recent construction), and if there are any
(serious) problems with this set-up. I could also be interested in hearing
about any less important drawbacks which other might have experinced (or could
imagine).
One minor problem is that the wire to the motor is twisted around the shaft
while mowing, but this is no problem if it is long and flexible enough - or 
maybe it is ...?

Bjørn Sørheim
bsorheim@sn.no