I just came into an old Cave Astrola GEM that is pretty old and beaten up, but once I took it apart it will clean up good.
The drive had been modified with a Pittman Servo motor, 24 v, about 1400:1 gear reduction according to the label. When I apply 12 vdc it turns at 1.3 rpm +\- a
second or two. The gearing on the motor is 46 tooth to a 144 tooth spur gear, attached to the worm shaft with a 100 tooth worm wheel.
Since the mount only came with an 8' f/8 ota and no electronics or controller, I have no idea what was driving the motor. Could someone explain the gear ratios
to me and tell me if they are close to being correct for a sidereal drive rate?
I thought I understood all that math at one time but it has since left the building!! :-)
Walt
The drive had been modified with a Pittman Servo motor, 24 v, about 1400:1 gear reduction according to the label. When I apply 12 vdc it turns at 1.3 rpm +\- a
second or two. The gearing on the motor is 46 tooth to a 144 tooth spur gear, attached to the worm shaft with a 100 tooth worm wheel.
Since the mount only came with an 8' f/8 ota and no electronics or controller, I have no idea what was driving the motor. Could someone explain the gear ratios
to me and tell me if they are close to being correct for a sidereal drive rate?
I thought I understood all that math at one time but it has since left the building!! :-)
Walt
