About a week ago I got a chance to try my CEM120 first time.
I aligned it and balanced both
Everything started well, but then I tried to go to M106, which was much higher in the sky than the earlier targets, and
I think the
I then re-engaged the drive and went to the zero-position. No "rattling" then. The
I found this video clip where the sound is similar.
Next evening I tried again.
As long as the temperature was around +10° (50°F), all was fine, but later, when the temperature dropped to +2°C (35°F), the problem returned.
I contacted iOptron, and they told me to loosen the gear mesh a bit - the manual says max 1/4 turns total. I turned that much and expected to feel a little free play, but there was none. I tried to turn it 1/4 turns more (1/2 turn total), and still no free play.
Last night I tried again if the adjustments helped the problem, but no. It was -5°C (23°F) and now both
Going to the zero position (even if now somewhat off) went fine without any noises, but from zero to Spica, which was at az 222° 18' alt +10°03' at the time, failed. Both axes stalled and made that noise.
The mount specs say:
Payload: 52kg (115 lbs), exclude counterweight
Operation temperature: -10°C ~ +40°C
My gear on top of the mount weight less than 16 kg.