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Hi, wondered if any CEM40 owners could tell me if they image with a C8 or similar and what results they get ? Also will I need 2 counterweights ? 

Scope / camera etc = 8kg.


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Hi. I have a CEM40 (nonEC) and I image with an RC6 + guidescope, main and guidecams, motor focuser - so slightly over 8kg.

I do use 2 counterweights. I could get away with one at the end of the shaft (just) but I prefer to use 2 closer in. EQ5 counterweights fit the CEM40 shaft a treat :-). 

My guidescope focal length is 280mm with an ASI290mini as a guidescope. I use PHD2 to guide and on rare good nights (still air and good seeing) the combo will do 0.5arcsec RMS guiding for hours at a stretch. On more typical nights (average seeing and wind gusts) it will still stay around 0.7 - 0.8 arcsec.  I set up and take down each night and the iPolar makes it super easy to get good PA quickly, which obviously helps the guiding. 

Let me know if you need any more info. 


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Thanks Paul, very helpful 👍 are you controlling the mount with ascom / laptop ?

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Yes, I'm using ascom and a Win 10 Pro laptop. I control my sessions using APT / PHD2. The only issue I've noticed is that on first attempt to use the iPolar it sometimes hangs, but I just close it down and restart when that happens. It always connects ok 2nd time.

Oh yes - and always park the mount to zero position at the end of the night. Don't turn it off and then move it to zero manually. It remembers where it was when powered off, so if you move the axes while unpowered, bad things happen next time you turn it on. Wonder how I know that? :-).

Once you have a workflow sorted and stick to it, life is easy and simple. Meridian flip functionality works well also. 

Good luck



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Thanks again Paul.

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Long story but the CEM40 is off the cards now 😒 going to wait for my HEQ5 to arrive ... Thanks for your help Paul.

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No worries and hope that we both get some clear skies. Enjoy the HEQ5!


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