Premium mount for observatory

Sorry, i can't give you a recommendation, because i only have experience with my EQ6-R. But i am very impressed of your selfmade observatory - with leather armchairs! Splendid! 
I know from a conversation with equinoxx that the 10 Micron mounts can track without the need of an autoguider - impressive, but they have their price…

Congratulations for your Obsevatory, it looks awesome!

I own a CGEM-DX since 6 years now and I can definitely say I'm happy with it even if sometimes it gave me little problems. The mount seems "susceptible" to the way you power it for instance. I solved a lot of electrical problems by using a power supply with an amperage way above the one requested, with surge protection and stabilized output.

In terms of performance I can't complain. The mount has some backlash but manageable and sometimes I feel the need to slightly readjust the worm gear.  I also have an hypertune kit ready for the use but I would like to get a new mount or wait for serious problems before installing it.

Anyway 6 years and she still looks awesome : [url=https://www.astrobin.com/full/299423/Q/?image_list_page=2&nc=]

[/url]The CGEM-DX is old thou so unless you find a very good offer I would have a look a the CGX-L.

Another good thing that Celestron Mounts have is the software. The ASPA (All Star Polar Alignment) is an awesome utility for instance and it takes me two minutes to refine the polar alignment if needed.

Anyway I never tried any other mount but I am sure there are many other good ones with medium/high load capability and at the same price range.

CS

Andrea

Hi Bruce

It might be helpful to know how you plan to image.  By that I mean, do you intend to have the observatory almost fully automated - controlled by something like ACP?  If so, then you might be better with a mount that has absolute encoders (like the 10 Micron).  But even then these mounts are not trouble free - indeed, I find that the two I use (a 1000 and a 2000) can be a little ... ‘temperamental’.  If you want to try using them ‘unguided’ (‘software model guided’ might be a more accurate term), you would also need extra bits and pieces - such as an environmental device, along with (mostly user-developed) software to build models and so forth.

If, on the other hand, you would like to be a little more hands on, then I would suggest that absolute encoders are unnecessary.  In my home observatory (which I operate ‘remotely’ from inside the house) I have a Mesu 200.  This gives 100kg carrying capacity and has proven extremely reliable (touch wood).  The Mesu is not even all that expensive (relatively speaking that is).

Some folks believe that you need absolute encoders when imaging remotely to ensure that the mount does not become ‘lost’ and start getting itself into positions that could cause it difficulty (which could get expensive).  But if you are attending to the start up every night, this can be fairly easily and safely managed with a non-absolute encoder mount.  I turn on my cheap IP camera to make sure that the Mesu is starting off roughly where it is supposed to be.  Then I slew (using Cartes du Ciel) to an object - usually a star at reasonable elevation, not too far from my Park position.  I take a 5 second exposure and do a Plate Solve in SGP.  This then syncs the mount and subsequent slews are accurate enough to get me where I need to be.  I can then turn off the IP camera.

Of course absolute encoders do not absolutely guarantee against getting lost.  Last night, for example, my 10 Micron mount decided that it was 2012 (1st March, if I recall correctly) - the time was also out by a few hours.  So last night’s first slew was far from accurate as you can imagine!  (It’s not the first time that it’s done that either.)

The Mesu would, I think, easily have the capacity for your C11.  Even though, managing to image with that would pose significant challenges.  The longest focal length I use is 1015mm.  I have a QSI 690 with that rig which gives me an imaging resolution of 0.75”.  This requires guiding of around 0.37” Total RMS - the Mesu averages around the 0.2 - 0.3 mark.  I don’t know what camera you would be using with the C11, but you might want to check that you don’t get too ‘fine’ (and un-doable no matter which mount you buy).  Perhaps some long focal length imagers could chip in and outline how they manage this issue.

If you did decide to shell out for an absolute encoder mount, I doubt that you’d be able to go unguided with a C11.  We use an OAG with the 1015mm focal length refractor on the GM2000 (we also guide the Tak 106 on the GM1000, but ... shhh.... don’t tell anyone that - and we’re not the only people guiding our ‘unguided-capable’ mounts - but keep that even quieter).   ;)

Good luck with your search.  Hope my 2c worth helped somewhat.

Steve

Guiding issues can stem from simple things like cable management (it really doesn't take much here to have an effect), the balance of the OTA (is is symmetrical / or offset somehow), something mechanical like movement or flexing (the list here is huge), or software configurations (in most cases, to aggressive).  If the mount is doing its job correctly, it's rotating at a blistering 1 revolution per day.  Stand back, you don't want to get caught in that…  Guiding corrections should not be huge.

I image at 2.3 meters with an AP-900.  There are no absolute encoders on this mount.  Very simple design.  Like Steve noted above, I have a camera to look at the mount and verify that everything looks correct, or it's used to move the mount into the proper position.  The mount is used night after night when possible and it does its thing nightly if the weather gods are kind.  Sure things happen, and there are times when I look at the ip camera in the morning all I can say is….  "Hmmmmm that's interesting.  I wonder what happened?"  This is perhaps the best reason to remember to set the tension on your clutches at a reasonable setting - not to tight.  Also, a cable management design that allows for these funky events, and that you can survive these without damaging equipment. Yes, you can operate without absolute encoders, but anything created can fault.  Even mounts with encoders.

Your system is complicated and requires alternatives to catch unforeseen faults.  Any correctly engineered system should have backups and redundancies to help catch stuff when things go wrong.   Think your system though, and try to incorporate watchdog timers or hardware solutions to catch faults if possible.   Investigate ways to monitor and identify faults so your system can alert you or independently act on these.   Your observatory will truly be an example or exercise in evolution  .

Personally, I really don't see why it's so important to have  "30 min unguided exposures".   I just use my OAG.  It's a tested and reliable method of keeping your system on a star.   Honestly, truly accounting for all the issues in the first paragraph is a big job.  I continually see cable management nightmares at starparties.  Making suggestions can be interesting.

Bruce Donzanti:
Thanks all for the great feedback, suggestions, and experiences.   AP promptly contacted me and resolved my issue on the Mach 1.  I decided to go with an AP1100 for the observatory as I am familiar with how they work vs. a Paramount.  I can add encoders later if needed and was thinking about OAG on the C11 but will see how that goes (Steve- I won't tell anyone what you are doing ).  I can get 60s subs to stack easily with the Mach 1 but then things begin to deteriorate after that.  So, for EAA that works but maybe not for AP.

Ive been very happy with my new AP1100GTO. I also like that it has the self adjusting worms. I had a CGX-L before and it was nothing but problems. I took it apart to set the backlash and gear mesh and found numerous casting fragments in the grease. It was a nice mount with home switches, software was nice and had alot of potential but there was little to no support, no documentation on even how to disassemble. That coupled with the QC issues made me go premium. Dont get me wrong, for someone who is not doing AP, the CGX series is a nice mount. Unfortunately it just couldnt get the guiding performance and I spent more time tinkering with the mount than observing. Clear nights are precious so I didnt want to keep wasting them.

I have a AP 1100 and no real problems other understand some of the technical details when first bought it.  It's an outstanding mount.

AP tech support is the best I have every had with any product Astromony related or otherwise

Call George at AP- he is very accessible extremely knowledgeable and will give you all the  time you need

Bruce w