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Old 06-06-2019, 10:03 PM
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lazjen (Chris)
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Join Date: Dec 2012
Location: Flaxton, Qld
Posts: 1,761
To operate it inside without mounting the weights and a scope, the counterweight shaft weight exactly matches the mount head. So to ensure everything can move freely, I needed to get the mount off the floor and safely setup to allow proper movement. After some messing around I got it sorted so I can do more testing.

One of the big differences to the G11 is the gear switch and axle lock mechanism. On the G11, it was a relatively simple operation to release a knob and move the mount freely for that axle. For CEM120, it's a bit different. The 2 knobs per axis have to be in specific positions for certain operations.

To move the mount around (e.g. to install it on a pier, etc): Gear switch unlocked, axle lock locked (for both RA and DEC obviously).
To do balance on an axis: Gear switch unlocked, axle lock unlocked - you can freely move the mount head around on that axis.
Normal operation: Gear switch locked, axle lock unlocked. Gears are engaged and the axle isn't fixed in position.

The combination of Gear switched locked and axle locked is not valid. The manual states that this should never be done.

While I understand why it's been done this way (and I suspect it might not have been possible to do a similar system to the G11), I think the G11 had the more user friendly approach.

I plugged in enough to get the hand controller going. Since I'm not outside, the GPS module couldn't get my position, so I set it approx manually.

The first thing I had to do was to set the zero position, which is counterweight shaft down. Easy to do. At this point I got to here the slewing noise. It's a bit quieter than the G11, but I was never really bothered by the G11 noise level anyway.

I picked a target (Jupiter) just to see/hear it slew to it. Again, quieter than the G11, but still there's enough to be noticeable in quiet locations.

One thing that does seem noisier than the G11 is when it is tracking. There's a very soft ticking type noise - again in quiet environments you'll hear it easily. It's been a while, but I can't ever remember hearing the G11 tracking noise.

In the hand controller, you can go to the zero position, or a park position. You can define the park position you want or use some presets (e.g. horizontal, etc). My custom defined park position didn't seem to work, so I'll have to work out what is going on there.
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