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CEM60 Mount Vibration

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#1 WebFoot

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Posted 31 August 2014 - 09:10 PM

Hi,

 

I think I've pretty well worked through all my startup issues with this mount, except this one.

 

There is a very significant vibration, lasting for 5 seconds or more, when the tube/mount is touched (e.g., focusing, a bit of a breeze).  It's entirely the RA assembly that's vibrating.  No adjustment in the locking screw for the clutch can reduce it beyond this (it gets worse as the screw is loosened).  No adjustment of the positions of the two counterweights makes any difference.  

 

The vibration is significantly greater (both in amplitude and duration) when the tube is heavy (e.g., a 30 pound SCT OTA) than when the tube is light (e.g., small refractor).

 

Do others have this issue?  I've talked about this with iOptron support, so far with no results.

 

Any useful suggestions?

 

Thanks.

 

Mark



#2 Nikolas234

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Posted 01 September 2014 - 09:43 AM

Hi Mark, there is a discussion in one of the CEM60 thread here on Cloudynights exactly about this subject. Do you mean there is a lot of backlash / movement back and forth in RA ? That could mean the gears are not meshing properly and a little adjustment is necessary, maybe on the belt, Paul Chasse talks about this in one of the above mentioned threads. And if the  meshing is fine, the tripod itself needs to be really steady, what is your mount sitting on for tripod? Size matter, the heavier and / or  longer the scope the more wobble there will be. The shorter or lighter the OTA the better the stability. Luc



#3 WebFoot

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Posted 01 September 2014 - 11:24 AM

Thanks!

 

It's not a matter of the tripod (it's on the stock iOptron tripod; not the beefiest, but that's not the issue).

 

This isn't micro-vibration; this is pendulum-like swinging of the entire scope/CW assembly around the RA gears.  You can see it swinging; you don't need to be looking through an eyepiece.

 

I don't know whether this is something that can be solved with adjustment, or if the mount is just not up to the task of carrying 30 pounds....  I would love it if some sort of relatively-simple adjustment would fix it.



#4 x6gas

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Posted 01 September 2014 - 11:36 AM

There was a UK owner reporting exactly this and I think it means there is a fault with your mount.  I'm not sure whether the other owner was able to sort out his issue, but id I were in your shoes I'd been looking for a replacement.

 

Mine easily carries a 35lb imaging load (either an 11" SCT or 5" refractor) and is rock steady.

 

Ian



#5 tazer

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Posted 01 September 2014 - 11:45 AM

Mine had a similar issue in RA. I could press the scope with a finger and see it move. It wasn't backlash or loose engagement knobs. After explaining this to iOptron support they told me to tighten the engagement knobs and back them off half a turn (even though I already explained it does it no matter how tight/loose the knobs were)... After reiterating the issue they said they'd ask the engineer and I never heard back from them on the issue. Since my 30 day return window was closing I returned the mount for a full refund and bought a G11. Almost 2 months later and they still haven't "gotten back to me."

 

Hopefully for the other iOptron users out there this issue is just a QA problem and not something that will manifest itself over time on units that are seemingly fine.



#6 Nikolas234

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Posted 01 September 2014 - 11:53 AM

Hi,

 

I would ask / talk to Paul Chasse but it might be in the belt tension. To my understanding it is easily adjustable. Ioptron should be able to instruct you how to do it yourself. It should not be moving as you explained. If your seller is located close to you,you could ask to exchange it. I have a Celestron EdgeHD 9.25 that I use with my CEM60 and when I do visual work dampening is a second or less and that's when tapping on the OTA . When I focus it is minimal.The better and more stable  tripod I bought made a big difference for my setup. Luc



#7 x6gas

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Posted 01 September 2014 - 12:57 PM

Hi,

 

I would ask / talk to Paul Chasse but it might be in the belt tension. To my understanding it is easily adjustable. Ioptron should be able to instruct you how to do it yourself. It should not be moving as you explained. If your seller is located close to you,you could ask to exchange it. I have a Celestron EdgeHD 9.25 that I use with my CEM60 and when I do visual work dampening is a second or less and that's when tapping on the OTA . When I focus it is minimal.The better and more stable  tripod I bought made a big difference for my setup. Luc

But honestly why should anyone have to do this with a brand new mount?

 

I am afraid that you're mount should never have passed QA and I would suggest returning it as soon as possible for a replacement.  It should not be like that.  Simples!



#8 tazer

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Posted 01 September 2014 - 02:07 PM

The way I viewed it was that I was essentially paying full price ($2,750 for mount + tripod) to beta test the mount yet not having my issues resolved in a timely manner. I vote for returning the mount for either a replacement, full credit towards another mount (if you bought it through a reseller), or a full refund.



#9 WebFoot

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Posted 01 September 2014 - 06:19 PM

Thanks; I agree that it isn't acceptable.

 

I have told iOptron that either this needs to be easily solved, or I need a new mount.  Fortunately, I'm a very good customer of my local astronomy store, and I have some confidence that they'll help resolve the issue.

 

I find it encouraging that others don't have the issue; hopefully, iOptron will do the right thing without me having to rattle any sabers.

 

Mark



#10 WebFoot

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Posted 02 September 2014 - 10:05 AM

I heard back from iOptron first thing this morning.  They have instructions on how to perhaps fix it, that I'll try.  When I get to it, I'll report back here, for completeness (in the hope that it'll help someone else down the line).

 

http://www.ioptron.c...Play_Fixing.pdf

 

I certainly looks plausable as the problem and the fix, and it looks like something I should be able to do just fine without sending it back to them.

 

Mark.



#11 tazer

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Posted 02 September 2014 - 11:07 AM

Glad they got back to you and have finally identified the problem. It looks a bit tougher than a beginner level fix but certainly doable. Looking forward to hearing back about your results.



#12 WebFoot

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Posted 02 September 2014 - 02:58 PM

Well, I read the directions, and my issue really wasn't listed.  I did the little things suggested anyway, and there was no change.  I have told iOptron support that I need to send the mount back to them.

 

I will keep this thread updated as things transpire.



#13 WebFoot

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Posted 05 September 2014 - 09:25 AM

I sent it back to iOptron yesterday.  We'll see if they fix it or replace it, or deny that there's a problem.  So far, they've been very responsive, so I'm optimistic.



#14 tazer

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Posted 05 September 2014 - 09:31 AM

I'm sure they'll identify and fix whatever the problem is. Too many folks are having good experiences with the mount so your, and my previous mount's issue, are probably just corner cases. Hope you get it back soon.



#15 WebFoot

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Posted 24 September 2014 - 11:07 PM

To update:

 

They have confirmed that my mount had unusually high vibrations/damping period.  They are sending me a replacement mount, which they have tested and find to have much less vibration.

 

I'll update when it arrives and I have an opportunity to put it through its paces.

 

Mark



#16 sctchun

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Posted 25 September 2014 - 12:43 AM

Hi Mark,

 

Hope the replacement mount resolves your problem.

 

Steven



#17 Astronewb

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Posted 25 September 2014 - 09:46 PM

Hi Mark,

 

Hope your replacement solves your problem.  After reading the thread I was inspired to take a short video of the CEM60EC mounted on a iOptron 42" pier.  I did a simple tap test on the tube and focuser while filming the live view target magnified about 5x.

 

http://youtu.be/sFRkmHUJAno

 

A correctly adjusted CEM60 should behave the same way under most circumstances.   I have checked this with a 44", 24 pound 152mm achromat and the result was the same.

 

Good luck...Paul


Edited by Astronewb, 25 September 2014 - 09:48 PM.


#18 tazer

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Posted 26 September 2014 - 06:43 AM

Paul,

 

If my CEM60 had been that stable I doubt I would have returned it (assuming it would have autoguided properly). Hopefully iOptron will put more eyes on the QA process so they all come off the line correctly adjusted.



#19 WebFoot

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Posted 26 September 2014 - 08:13 AM

Yeah, that's incredible, compared to what mine was.  Hopefully, the replacement one is something like yours.



#20 Astronewb

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Posted 26 September 2014 - 10:46 AM

I

If my CEM60 had been that stable I doubt I would have returned it (assuming it would have autoguided properly).

 

 

I completely understand your concerns.   The firmware updates had been a learning process and not completely finished for the first few months after intro.  

 

The latest firmware release is excellent as far as tracking and auto-guiding (v140825).    I recently received a new FT focuser for the AT10RC that I had been waiting 5 months for and got a chance to test it at full focal length (2000m) last week.  With basically stock PHD2 settings at 2000mm and a simple polar align and One Star align I took some very nice 10 minute subs to check focuser alignment and tracking:

 

15108226918_1663aac96a_b.jpgAT10_2000mm_cem60ec_600secs by Astronewb2011, on Flickr

 

These results equaled or exceeded the results I got with a iEQ45 and Telescope Drive Master in the past so I'm quite happy with the mount at this point.   Right after I captured the image above I slewed to M76 to start an imaging string.  The target was dead center in my fov (excellent go-tos) but naturally clouds moved in half way through a ten minute exposure so I called it a night.... :(

 

All the best...Paul



#21 WebFoot

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Posted 17 December 2014 - 03:19 PM

To bring this thread to its unfortunate conclusion, I'll relate my remaining experience with this horrible mount.

 

To review the bidding, my CEM60 had a horrible wobble; just touching it (e.g., focusing) would set it off to wild wobbling, which took five (or more) seconds to dampen to a livable level.  It made the mount unusable with my SCT tube (it was fine with the Sky90).  The wobble was the entire RA axis acting like a pendulum, not anything to do with the substandard tripod.

 

After working with iOptron customer support for an unfortunately long time (no good deed goes unpunished; next time I'll just send the horrible thing back within the 30 window for returns), I sent it back to them to fix the problem.  I had to pay shipping both ways (this is not my idea of customer support, BTW).  They sent me a new one after some weeks.

 

The new one was identical, in the horrible wobbling.  iOptron insisted that it was performing properly.

 

Ultimately I returned it, eating the bitter pill of their absurd 15% restocking fee.

 

I replaced it with a Losmandy G11.  It works.  Imagine that.

 

Morals of the story:

 

1.  Don't buy iOptron products;

2.  Failing to observe 1, return it immediately if there's a problem.  They want to string you along beyond the 30 day free-return time.

 

It may be that iOptron makes some mounts that perform according to specs.  Unquestionably, they sell lots of mounts that don't; I got two of the latter.



#22 tazer

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Posted 17 December 2014 - 03:41 PM

Sorry you had a bad experience and had to eat the restock fee, but glad the G11 is working out well for you. I was lucky enough to buy my mount through OPT and registered my issue with them before the 30 day mark. It did bother me a little that the docs that come with the cem60 suggested you work through your issues with ioptron and not the reseller. It's certainly a little disconcerting to get a mount that doesn't function properly and then watch your return window slowly evaporate while they "check with the engineer."

You shouldn't have to pay to beta test a mount.

Mark

#23 orlyandico

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Posted 18 December 2014 - 05:06 AM

The title of this thread should be corrected so that potential CEM60 buyers can find it.

 

It does seem from all the CN  threads that this mount is an ongoing science project..



#24 WebFoot

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Posted 18 December 2014 - 10:01 AM

Agreed; I've submitted a request.



#25 TimP

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Posted 18 December 2014 - 10:53 PM

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 think you can do a search on just about any brand and find complaints. That is unless you spend 10 grand. Here's one statement I found about the G 11.---- (Scouring the internet for information (as always), I found a host of other GM8 / G11 owners who's mounts suffered identical symptoms (same as when I started researching my G11 problems). Actually there were so many others, that I started getting that sinking feeling deep inside. (the first of several).------- When I was looking for a new EQ mount a few years back just about the same time the CGEM DX came out, Everyone spoke highly of the mount so I pulled the trigger and bought one.  After 2 trips back to Celestron, one to fix and one to replace it. Also one trip to Hypertune it. All of my efforts failed and now the mount resides in the box it came in. I use the C11 HD on CEM 60 and the CGEM DX tripod is modified to fit the CEM60. Although my CEM 60 does not wobble I do suffer from some software glitches which I hope the new update will take care of when it comes out. Long story short, When you buy in this price range your either going to get a good one or more often then not your going to have to work the glitches out.

 

Tim




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