For iOptron Internal Use Only
1
GEM28 Worm Play Identification and Adjustment
Tool needed:
a set of metric Allen wrench and a
small flat top screw driver, a pair of nose pliers or
tweezers.
GEM28 Ring Gear Cover Removal: RA
The design of GEM28 will need to remove the DEC
unit from the mount in order to expose the RA ring
gear compartment.
1. The DEC unit is connected to the RA axle via 4
socket screws. Two is on side the DC unit. One
is on bottom of the DEC unit. The fourth one is
inside the mount. Remove front polar scope
cover and look into the mount, you should see it.
2. Remove red CW shaft mounting adapter from
the bottom. The bottom screw now is easy to
access.
3. To access the top screw, you may use a long
arm ball head wrench through the RA axis
opening to release it.
4. Pull the DEC unit off from the RA axle. Remove
three screws and take off the RA ring gear
cover.