Premium mount for observatory Generic equipment discussions · Bruce Donzanti · ... · 12 · 857 · 0

umasscrew39 12.53
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I have just completed my home observatory (starzantiskiesobservatory.com) and I currently have my C11" on an AP Mach 1.  The total weight with accessories is well under the load capacity so no issue with that.  However,  recently I am having tracking problems with the mount.  I am trying to get AP to help me but I have had issues in the past with it.  So, I am wanting to explore other possible options.  I realize AP mounst are expensive, well-respected premium mounts but I guess I have had bad luck with mine.  I see great images on this site with less expensive mounts like a CGEM, CGXL, etc.    I would like to hear from others there experiences with mounts that they have had good success with for imaging, realizing none are perfect.

Bruce
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khrrugh 3.21
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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...
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Jens-M. 0.00
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Dear Bruce: The end of my dreams would be either the GM 1000 or GM 2000 from 10Micron. Seems to be at present the most sophisticated technology and material quality. They really know what they are doing...

CS!
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Epox 0.00
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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 : <a href="https://astrob.in/299423/Q/"><img src="https://astrob.in/299423/Q/rawthumb/gallery/get.jpg?insecure"/></a>

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
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gotak 0.00
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Congrats on the Obs. I am sure you'll get a lot of enjoyment out of it.

I have been known to recommend iOptron occasionally  (LOL! I do so all the time).

For a C11 you'd need the CEM60 as a minimum but I'd recommend the CEM120 and if it's possible the CEM120EC or EC2. Currently I am using a CEM60EC which is working just fine but I haven't moved up to a C11 just yet. If you want to find out the ins and outs of the CEM120 I can get you an invite to a CEM120 only group where the CEM120 refugees have ended up after being treated badly at the forum that shall not be named. I don't think you'd likely be disappointed with a CEM120 for your use case and it would open the doors to future expansion, all at a cost you'd like recover just by selling your problematic mach1.

The strength of iOptron is their support. It's only available over email but  they are very responsive, I have been surprised to get a response in the middle of the night. Some people hates that you can only reach their techs over email, but I see it  differently as there's no point jabbering away on the phone if you end up needing to send over guide logs or other data to get any traction. A very recent example of how responsive they are would be my current discussion with them about my CEM60EC and some spikes after meridian flip. The spikes don't really impact the image even at 0.54" scale, and I even suspect it's actually the mirror in the Edge8, but they turned around and sent me beta firmware that has some improvements to EC tracking for the CEM60EC, fresh off the press. Some would call it beta testing on the end user, which is it but they aren't forcing me to try it right? Frankly, I prefer being given the option to try.

And if you are familiar with my posts before I decide to self quit the forum that shall not be named, I believe that iOptron has no risk for long term support as they have demonstrated they have parts in stock for mounts that's 9 years old and out of production. They are even still supporting equipment that was originally the product of the Chinese firm that became part of the Sino-American joint venture that is iOptron, all the way back from 2009.

I find it interesting you felt the need to explain that you realize AP are well respected and expensive, but then blame bad luck. From my perspective considering the price why are your issues not promptly resolved? All my iOptron issues are promptly responded to and even when the issues prove difficult to pin down they never gave up but work with me until it's fixed. All at a much lower price point as well.
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gnomus 0.00
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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
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umasscrew39 12.53
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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.
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trobison 0.00
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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.
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flywaldo@gmail.com 0.00
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I've ordered a next generation Mesu 200 from Lucas Mesu. I have an automated remote observatory that I currently run using a CGE-Pro mount. It is OK, but not great, and not up to the level of work that my new dome will be able to support.

Enjoy!

Eric
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rhombus 0.00
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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.
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umasscrew39 12.53
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Terry Robison:
our 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  .

Thanks for the advice and tips, Terry.

Ive been very happy with my new AP1100GTO


Good to hear
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Brucew 0.00
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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
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laperuz 0.00
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Hello, Bruce! Really nice observatory design and implementation!
I want to second Steve's comments on MesuMount 200. I have Mesu for over 6 years now, it's probably the best trouble-free piece of gear I have ever had (again, knock on wood!). Compared to Steve I have EdgeHD 14" mounted on it. With all the equipment I figure it is about 33-35 KG. Handles it like a charm. I was until recently imaging at f/7.7 (app. 2750 mm FL). But lately switched to f/11. That is close to 4 m FL! At first I was a bit nervous, but low and behold, there are no issues with guiding, star roundness, etc.
There are, as mentioned, those issues with initial GOTO. I use a Plate Solve 3, that's build in SiTech controller latest software (SiTech is Mesu's default controller). Usually if it's not too far away from Park position it'll platesolve without any issues. After syncing, the Mount it is good to go with pointing accuracy of about 5-10 arc-min. You'd probably need to platesolve again at your intended  target, especially at f/11. Guiding is very smooth. I'm routinely getting 0.2-0.3 arc-sec RMS at this 3910 mm FL. It is sky-limited, for sure. My guiding sub-frames are usually 5 sec.
Good luck! And Clear Skies,
Ian
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