Exactly right. The CEM60 doesn't use springs as the worm block is held against the main gear via magnets. Really slick btw. The worm then rides smoothly along. I feel there is room to improve the way the knob rests when engaged and I excited to see how things go. iOptron has been very responsive to my feedback so far.
Hopefully the clouds will clear, my 11" EdgeHD will arrive this week and I can start doing some actual testing.
Thanks for the review, the mount looks nice.
The clutchless design is nice but you need to be very careful when disengage the worm wheel because it is very easy to damage the worms. I had a ZEQ25 and I didn't like the idea of disengaging the worm wheels just for balancing the mount.
Another issue with this design is that every time you engage/disengage the periodic error profile is modified. I have no clue how the CEM60 is affected by this cause it uses magnets to keep the right tension of the worm.
My thoughts on this are that since the main gear doesn't move independently of the system when you disengage the worm, it is possible to re-engage the worm in exactly the same position each time. You just need to go back to zero position(home) and make sure you are correctly lined up when you mesh the two back together.
On any of my standard GEM mounts when you release the clutches you are able to physically move the main gear, re-engage the clutch, manually slew back to home, loosen the clutch, move the main gear, re-engage the clutch, slew back to home and so on. So you could use 180 degrees of the main gear one day and the other 180 degrees the other. This would affect the PEC if there were issues with that side of the wheel.
However that being said, most of the PE in mounts comes from the gear box and the worm gear. This mount doesn't seem to have a gear box on the motor and drives a belt directly to the worm. So I don't think there is much PE there. So that leaves the worm. Regardless of where the worm lands you would carry that PE with you. So that then leaves the worm wheel or main gear. As long as you can accurately line up RA when you engage, you *should* have no troubles with the PPEC profile.
I admit it doesn't seem easy since there are no alignment marks to go by. I have to essentially go by sight. Doing that in the dark is going to be fun. I'll probably end up adding my own marks.
I look forward to your thoughts on this. My specific mount has the encoder on the RA which should essentially negate the need for a PPEC profile anyways. However if I can convince iOptron to allow some method of turning the encoder on and off I would love to test and PEC train the mount separately just to see how it is.
On another topic:
One of the things I was thinking about last night was about the raw PE on these mounts. I am curious if the mounts with excellent PE end up being the mounts without the encoder and anything with horrible PE they just thrown the encoder on it to deal with it. I would love to know what my mounts raw PE is without the encoder. I may have to find a pair of wire cutters and get to work!