iOptron CEM70 User manual

CEM70 Belt Tension Adjustment
Tool need: a set of metric hex keys, a small flat head
screwdriver
RA Belt Adjustment
1. Set the mount to Zero Position. Locking RA axle by
insert the locking Allen wrench. Release RA gear
switch but keep the DEC gear switch engaged. Flip
the mount head to let it sit on dovetail saddle.
2. Release altitude locking screws on both sides. Turn
the altitude knob to adjust it to ~ 40 degree to
expose the RA motor and belt. Lock the GPS side
altitude locking screw but remove motor side one.
3. Remove 5 socket screws to separate mount left
base supporting plate.
4. The motor was secure by 3 socket screws. To adjust
the belt tension, loosen these screws a little bit.
5. Tension the motor properly. If need more tension,
insert a flat top screwdriver and gently push the
motor outwards while tighten the screws. When the
belt can be pushed down 3mm, it should be about
the correct tension.
Remove this one

6. When put the side plate back, it needs be very
careful not to jam the wires.
7. Slide the side panel on and arrange the cables to go
into the slot.
8. Put 5 screws back and slightly tighten them
9. Remove two screws that hold the RA control board
cover to expose the cables that go to the RA board.
And slightly pull the cables to make sure they move
freely.
10. After secure the side cover. Put the altitude locking
screws back and lock it.

DEC Belt Adjustment
1. Rotate the mount in RA to expose the DEC motor
cover under the DEC saddle. There are 4 hex head
screws hold it in place. One is blocked by the DEC
control board cover.
2. Remove two screws that hold the DEC board cover.
3. Remove two screws under DEC ring gear
compartment.
4. Remove another two on the back.
5. Slightly release 3 screws that hold the motor on
worm assembly. To tighten the belt, gently push the
motor outward. Hold the motor while tightening
the screws. Check the mount performance before
put the cover on.