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Old 26-08-2020, 08:00 AM
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The_bluester (Paul)
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The_bluester is offline
Join Date: Feb 2011
Location: Kilmore, Australia
Posts: 2,803
ioptron CEM70G initial impressions

So, after a couple of months wait due to both COVID impacts on production around the world, shipping delays worldwide and the frenzy of sales that COVID seems to have induced on astro gear, I received my new CEM70G a couple of days ago. Time for some initial thoughts.

Firstly, the mount comes well packed, it is in a lined aluminium case and the case itself is double boxed for shipping. The only potential trip up I can see is that the supplied counterweight ships in a separate box (Presumably for shipping weight reasons) which is an opportunity for it to get separated in the shipping process.

My initial impressions of the mount are good, basically the whole thing seems to be comprised of stainless steel and die cast or milled aluminium, everything you can touch feels nice and solid. The gear switches are positive to operate and when they are released the mount moves very smoothly and freely for balancing. It moves so much more freely that the Atlas (AZEQ6 clone) even in Dec (Which is the easier axis to balance on the Atlas) that as soon as I mounted my scope I can see I really need to relocate my focus motor if I want it to balance properly. It sits out to one side and makes proper dec balance more or less impossible, which I never really picked up on the Atlas.

Size wise it is a bit of a beast coming from an AZEQ6 type mount. The only (Not really negative, just ambivalent) build quality note is about where the threaded cap for the polar scope is screwed in to. It screws into the cast alloy elbow that connects RA shaft to the counterweight bar and the thread there is cut after the part is coated so it stands out as the only bit of raw aluminium in sight. Bit of a first world problem if that is the worst I can find. It is only visible when you are using the electronic polar scope, the rest of the time that plug serves as a lens cap. Visually it looks a little strange when I have been using a GEM until now, it looks like the counterweight is pushed way, way out in front of everything but that is just because on a GEM the telescope would be right on top of the counterweight and on these it is sitting back between the bearings.

With the commander software loaded it connected straight up to my imaging PC. The ability to find it's own home position from any location is a great function to start it off, the guide cam and polar cam connected straight away, connection to my imaging software (Voyager) was as simple as selecting it, after homing itself, goto commands on the bench resulted in it going more or less where I expected. The GPS module connected up and set the time and location from inside the house, but not from inside my garage (It was near a window in the house and under foil backed insulation in the garage which probably blocked the GPS signals)

A quick dummy mount of my gear in the garage and connections with whatever cables I had available say everything seems to work via the USB3 hub and power connections, better still, even on my converted Celestron tripod, crashing the camera is not possible. No matter where the scope is pointed the RA hard stops limit travel so that the camera has maybe 20mm clearance to a tripod leg at worst, it will be even better on a pier. If I mess up the alignment of the electronics badly enough to run it into the hard stops I might mechanically damage the mount but the camera and telescope will be protected, not a bad trade given that they combined are still worth more than the mount is.

The only thing that will need watching is that care is needed in the order things are set up after pulling it out of the case. it should be in the case with the gear switches released and the RA axis is locked by the allan key provided to mount it on the tripod. It comes to a point where you need to pull that key out of the axis locking hole to do up the socket screws (Captive ones) that bolt the mount down on the tripod or pier, and if you forget to engage the RA gear switch first you will have a bit of a nasty time! On the CEM60 I believe it is bolts/studs in the mount plate that you sit the mount over and then thread tube nuts on by hand before tightening with the metal bar that is supplied with those mounts to lock the axis instead of the allan key that comes with the 70. That means on those mounts you have more likelihood of having fitted the counterweight bar which more or less balances the RA axis, before pulling the locking pin out. It might or might not do damage to the mount if it were allowed to flop over to the stop, but I reckon if it grabbed your finger you would never forget the right order to do it in again!

Performance wise I am mounting about 30% of it's rated payload with my SVX80T and camera, and it flings that around like it is not even there, there is no discernible difference in the start and stop of slews with it on or off. At this point I can not test any more until I get a clear sky, currently that looks like Friday, so if that comes to pass I will set it up and test the polar camera and guider, and hopefully move on to fettling the corrector to sensor spacing for my new camera.

Last edited by The_bluester; 26-08-2020 at 11:25 AM.
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