So, What your trying to get across is that all CEM60 mounts are junk because you had a problem. I just did a search and found many complaints about the G 11.
I had a CEM60 with similar issues as WebFoot's and a similar customer service experience. I have never claimed that all CEM60's are junk, rather they're new and have issues that need to be worked out. I went from a CEM60 to a G11 because I wanted something that would work right out of the box. iOptron felt the CEM60 was ready for the general public but mine definitely wasn't. I shouldn't have to spend months beta testing the mount at full price when members of the beta team got a substantial discount on their mounts.
Me, personally, whenever I buy something, I never read the positive reviews, only the negative ones.
Agreed. I knew my purchase of the CEM60 was a gamble as there was no history on the mount what-so-ever. I was prepared to return it if it didn't do exactly what it was advertised to do. I had researched the G11 and noticed that most of the negative reviews were about the Gemini II hand controller and were all a couple of years old. The mount design itself is well known (it hasn't changed much in 2 decades) and its few issues (e.g., backlash, 76s error, etc) were well discussed.
If I put weight in positive reviews I'd be picking up a CG5, a C11 and getting ready for 30-minute subs all night long with a 90% keeper rate...
I think it is fine as long as people are reporting facts--things actually happened. I even believe that sharing facts (no matter positive or negative) should be strongly encouraged in our community. No one should be blamed as long as what he/she shares are facts. Then it is up to the readers to decide whether these are isolated cases or a general trend for that particular product.
There's a time and place to vent about vendors. If this thread is to retain value then venting shouldn't be done here (not that I think it has.) The issues WebFoot and I experienced are legitimate. They don't affect all CEM60's and, unfortunately, iOptron doesn't know the cause of the problem. My mount had stalling issues on top of the RA play. I would describe the RA play as being able to push against the RA axis and seeing the saddle move 5+ mm. It wasn't slack or backlash, as the worm was fully engaged. It felt more like a belt or something was flexing internally. Unfortunately my attempts at guiding yielded very poor results. Actually, my results seemed to indicated that guiding was essentially useless as I was getting close to 8" peak-to-peak of error which match the encoder printout that came with the mount. iOptron had me changing my guiding settings instead of addressing the RA play issue which I felt was the real culprit. Sadly, I never took any long duration (i.e., greater than 2-3 minutes) exposures without my stars being elongated even while guiding.
I wouldn't blame you if you wanted to point the finger at the user. Heck, even though I had been guiding my CG5 for a couple of years even I doubted myself. That doubt was quickly dispelled the first night out with my G11 though. After getting guiding going and having a PHD2 graph which looked like I expected it to (better in fact) I took a 5-minute exposure with great stars, then I took a 10-minute exposure again with great stars, and finally I took a 20-minute exposure yet again with great stars. And that's the experience I was looking for. A mount that just worked.
I'm sure iOptron will work through all the issues and have a reliable product at some point. In fact, I don't recall seeing many other reports of the RA play/vibration issue recently so perhaps they've already taken care of that problem. I do sincerely hope the CEM60 matures quickly which will provide another alternative for folks out there.
I had an experience similar to both of these. Been through two CEM60s and have seen both the promise of the engineering design and (IMO) incompleteness of its productization. In my opinion, the mount is not ready for widespread amateur use due to lack of consistency and QC in manufacturing, the ease with which it can be damaged, and the overstatement of its specifications. That does not mean it cannot perform exceptionally when used properly. I bought a new CEM60, paid full price and immediately had to replace it because it wouldn't track correctly at all (defective board). Got a replacement and had fun with very accurate GoTo, but had trouble with RA play and had to futz with worm gear end cap. Also, with <30 lbs it was very shaky no matter how tightened down everything was (on a 48" pier). Finally measured PE through slow horizontal slewing across camera frame and found it to be much higher than advertised (+-15 arcsec or so) and I was never able to get tracking and guiding as smooth as I expected. Moreover, tracking and guiding were exceedingly dependent on weight balancing and I had to use weight velcroed to to the side of my OTA to carefully adjust the weight symmetry on the OTA itself in order to be slightly east-heavy, and then readjust weights after meridian flipping. iOptron refused to take back the second mount (past 30 days, but my opinion was that it did perform as advertised), but I traded it back through OPT at a slight and reasonable loss and bought an AP Mach1. iOptron claims the worm gear was damaged through user error to explain tracking problems but they still fixed it so it could be resold, so I give them credit for that as well as their customer support which was very good when I had questions. I understood the magnetic gear engagement mechanism as well as requirements for transport of the mount, and I could not prove that I did not personally damage the gear despite having done nothing obvious to do so. I have not had a single problem with the Mach1. It has behaved flawlessly since the first time I turned it on and is phenomenally easy to use. It is rock solid on a 42" pier, does not have problems with play in either gear, and tracks and guides nicely without undue need for precisely fine-tuned empirical parameters. If a little play does build up, it's loosen 2 set screws, gentle tap, retighten set screws and it's rock solid again.