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Atlas EQ-G Autoguiding Performance

astrophotography eq equipment imaging Orion
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#1 Kugelblitz101

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Posted 17 June 2019 - 03:25 PM

Hello CloudyNights,

 

I recently got a replacement Atlas EQ-G from Orion as my previous one had significant backlash in the declination. I tried it out a few nights ago and found that the guiding performance of this new mount is significantly worse than my old mount (which usually stayed around .6"-.7" RMS). I've attached a guide log below; however, the TL;DR version is that the RMS average for the imaging session was 1.16" according to the log, but I would routinely come out and see that it was as high as 1.3"-1.5" even when pointing North (Iris Nebula). I'm just wondering if this is normal performance from the Atlas, or if there's some additional mechanical problem in the mount (to me it looks like there's significant declination backlash again and some "stickiness" in the RA). Any suggestions or comments would be greatly appreciated, and I'd be more than happy to provide any additional information!

Guide Log (Guiding assistant starts at 22:29:38 and Imaging starts at 23:30:32): https://openphdguidi...2_logs_kwRc.zip

 

Thank you,
Ethan



#2 PirateMike

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Posted 17 June 2019 - 04:40 PM

I have the Atlas AZ/EQ-G Pro. Is that the same mount as yours? If so...

 

When I got my mount it was a lemon, but I really didn't want to send it back for a few reasons, so I fixed it myself and now she works fine.

 

The sad truth about these cheap mounts is that they are not manufactured with loving care, they are mass produced and keeping manufacturing costs down seems to be a priority.

 

If you feel that you have the ability, maybe you need to fix the issues on you own. If not you can return the mount and hope the next one is good.

 

Here is an image I took with my Atlas AZ/EQ-G Pro mount. I shot 20 minute exposures.

 

 

NGC 2244-C2 One Frame small.jpg

 

 

Anyways an RMS of .6" - .7" is not too shabby at all.

 

 

Miguel   8-)

 

.


Edited by PirateMike, 17 June 2019 - 04:41 PM.

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#3 bobzeq25

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Posted 17 June 2019 - 05:01 PM

I have the Atlas AZ/EQ-G Pro. Is that the same mount as yours? If so...

 

When I got my mount it was a lemon, but I really didn't want to send it back for a few reasons, so I fixed it myself and now she works fine.

 

The sad truth about these cheap mounts is that they are not manufactured with loving care, they are mass produced and keeping manufacturing costs down seems to be a priority.

 

If you feel that you have the ability, maybe you need to fix the issues on you own. If not you can return the mount and hope the next one is good.

 

Here is an image I took with my Atlas AZ/EQ-G Pro mount. I shot 20 minute exposures.

 

 

attachicon.gif NGC 2244-C2 One Frame small.jpg

 

 

Anyways an RMS of .6" - .7" is not too shabby at all.

 

 

Miguel   8-)

 

.

What were the basic issues you fixed?  I'm not asking for procedural details.


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#4 Kugelblitz101

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Posted 17 June 2019 - 06:20 PM

I have the Atlas AZ/EQ-G Pro. Is that the same mount as yours? If so...

 

When I got my mount it was a lemon, but I really didn't want to send it back for a few reasons, so I fixed it myself and now she works fine.

 

The sad truth about these cheap mounts is that they are not manufactured with loving care, they are mass produced and keeping manufacturing costs down seems to be a priority.

 

If you feel that you have the ability, maybe you need to fix the issues on you own. If not you can return the mount and hope the next one is good.

 

Here is an image I took with my Atlas AZ/EQ-G Pro mount. I shot 20 minute exposures.

 

 

attachicon.gif NGC 2244-C2 One Frame small.jpg

 

 

Anyways an RMS of .6" - .7" is not too shabby at all.

 

 

Miguel   8-)

 

.

Thank you for your reply! Unfortunately I don't have the Pro version of the Atlas but still your experience is greatly appreciated! That image is phenomenal also bow.gif !


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#5 PirateMike

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Posted 17 June 2019 - 06:32 PM

What were the basic issues you fixed?  I'm not asking for procedural details.

 

 

Hey Bob,

 

I had the machine shop mill the meeting surfaces of the tripod and the mount head.

 

I put cement in the inner legs to make the mount setup bottom heavy.

 

I added a spreader

 

I "resurfaced" the worm gear and changed the bearings. (This was the magic trick!)

 

I changed to grease to something really good.

 

I adjusted the mesh and reassembled the mount with much care.

 

I think that's about it.

 

The reason I didn't want to return it is that the shipping from PR to the states is expensive and the sales tax here of 11.5% is beyond reasonable. I think Orion made a big mistake when they accepted my order and shipped it free of charge through the post office. Total savings from the regular price was $600, and I didn't even have to pay tax!. I wasn't sending it back, no way!

 

 

Miguel   8-)

 

.


Edited by PirateMike, 17 June 2019 - 06:36 PM.

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#6 amoncayo

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Posted 17 June 2019 - 06:48 PM

Hi Ethan,

 

I have had an Atlas EQ-G for almost 4 years. The first year I used it primarily for visual. After that I switched to imaging with an 8" RC. After well over one year of tinkering with gear mesh adjustments, guiding settings, PE correction via EQMOD, and as a last resort performing a Rowan belt mod; the mount has simply never worked consistently. The best guiding I ever achieved with the mount was close to 0.5" total RMS. Typically, it danced around from just below 1" to as much as 1.5" total RMS. Backlash was an issue and lessened with the belt mod, but continued as a problem with the mount. I did have stickiness in RA as well. I adjusted that by playing with the axis lock nut at the CW bar attach head at the expense of some play in the axis.

 

Ultimately, I gave up on the mount for imaging. It is sitting in my garage and has been unused for many months. Someday I'll rebuild it from scratch again and dedicate it to visual once my grandkids are old enough to go out at nights with me.

 

I ended up upgrading to a CEM120. My experience with that mount has overall been positive. As such, I recently I acquired a CEM40EC. Perhaps I had a lemon EQ-G, but the difference is night and day between guiding consistency of the iOptron mounts compared to the EQ-G.

 

As another data point, my brother has an EQ-G as well. He has only once ever gotten below 0.8" total RMS guiding error. His dances around from right around 1" to under 2". The good news for him is that he uses it at an image scale no less than 2.5"/px. I tend to be down around 1"/px or lower.

 

Al

 

I recently got a replacement Atlas EQ-G from Orion as my previous one had significant backlash in the declination. I tried it out a few nights ago and found that the guiding performance of this new mount is significantly worse than my old mount (which usually stayed around .6"-.7" RMS). I've attached a guide log below; however, the TL;DR version is that the RMS average for the imaging session was 1.16" according to the log, but I would routinely come out and see that it was as high as 1.3"-1.5" even when pointing North (Iris Nebula). I'm just wondering if this is normal performance from the Atlas, or if there's some additional mechanical problem in the mount (to me it looks like there's significant declination backlash again and some "stickiness" in the RA). Any suggestions or comments would be greatly appreciated, and I'd be more than happy to provide any additional information!

Guide Log (Guiding assistant starts at 22:29:38 and Imaging starts at 23:30:32): https://openphdguidi...2_logs_kwRc.zip

 

Thank you,
Ethan



#7 Pauls72

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Posted 17 June 2019 - 11:07 PM

I have had my Atlas EQ-G for 11 or 12 years now. When It was about 7 years old I did a super tune on it, replacing the worm gear bearings (one of them had a bad spot), replaced the old tar type grease with SuperLube synthetic. I also added a Rowan belt drive kit. Sometime before this I made an additional spreader to help stabilize it. I had replaced the altitude adjusting bolts with stainless ones after bending one. I have since installed an EQ-G Rail kit, an ADM Dual Saddle and a longer/larger counter weight shaft. I use a PoleMaster for polar alignment. I have PoleMaster adapters on both my Atlas mounts.

 

I bought a used even older Atlas EQ-G. It had been stored unused outside under a cover for a number of years. It took some work to fix a few things. It doesn't have the mod's but has been super tuned with new worm gear bearings.

 

I have imaged with both of them, with no problems. The guiding is slightly better on my original mount. Here are the graphs from my original mount

 

RA

PHD2-Log-Dec_zpsto7ni9bo.png

 

Dec

PHD2-Log-RA_zpslnyh618k.png




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