iOptron CEM40 Instruction Manual page 18

STEP 6. Install Counterweight(s) and Telescope
Before putting on CW, make sure the mount is at its zero position, i.e., CW shaft points to the
ground. Disengage the R.A. Gear Switch and insert the Allen wrench to lock the RA axis before
loading the CW. Remove the CW Safety Cap at the end of CW Shaft. Glide the CW over the shaft with
the larger hole opening facing down. Tighten the CW Locking Screw to hold the CW in place. Place the
Safety Cap back onto the shaft. Move the CW to the bottom of the shaft and tighten the CW locking Screw.
You may need more CW for heavier payloads, or a smaller CW for lighter scopes.
CEM40 is equipped with a Vixen/Losmandy-D dual saddle. It can receive either a Vixen or a
Losmandy-D plate. Release the dovetail saddle locking knobs and slide the telescope dovetail plate into the
saddle. Tighten the saddle locking knobs.
STEP 7. Balance the Payload
Before mounting an OTA, make sure the arrow on dovetail saddle is facing front. If it is not,
release DEC gear switch and rotate dovetail saddle.
After attaching the scope and accessories, the mount head assembly must be balanced in both DEC
and RA axes to ensure minimum stresses on the mount driving mechanism.
CAUTION: The telescope may swing freely when the R.A. or DEC Gear Switch is disengaged.
Always hold on to the mount and/or telescope assembly before releasing the Gear Switches to
prevent it from swinging, which can cause personal injuries and/or equipment damages.
Set the mount at Zero Position. Disengage both RA and DEC gear switches and move the mount to
horizontal position to check balance. Return to Zero Position for balance adjustment. Balance the DEC axis
by moving the scope with accessories back and forth in the mount saddle or within the scope mounting
rings. Balance the assembly in R.A. axis by moving CW along its shaft. Repeat the process until both DEC
and RA axes are balanced.
CAUTION: The balancing process MUST be done with Gear Switch at the total disengaged position!
Otherwise it might damage the worm system.
Figure 22. Install Counterweight
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