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Atlas overhaul...stop me before its too late!

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#26 Dwight J

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Posted 02 June 2009 - 04:15 PM

Hi, this is my first post after lurking for a while. I wished someone had warned me against the same thing. The mount is still in pieces with the polar shaft jammed in the casing. I can still revive it by pounding it out - the apparent cause is using a silcone based grease - it causes it to jam up when trying to reassemble. I got a Tak EM200 for imaging instead - autoguided right out of the box without any fiddling with either the mount or guiding parameters. I would recommend if it works, don't fix it! Good luck - Dwight

#27 Tim C

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Posted 03 June 2009 - 10:23 AM

What drives so many folks to consider overhauling the EQ6 mounts? Is the PE in these mounts frequently too "rough" to guide out? Some say they work great when guiding but many seem to not be satisfied. Tough to weed through anecdotal evidence vs. real facts.

#28 Bob D

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Posted 03 June 2009 - 01:45 PM

What drives so many folks to consider overhauling the EQ6 mounts? Is the PE in these mounts frequently too "rough" to guide out?


I am also very interested in answers to this question -- especially for imaging at focal lengths between 1500 and 2500 mm.

#29 Brodie

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Posted 03 June 2009 - 02:20 PM

i have no idea what the PE is in my mount (not really sure how to even calculate it). but i do want to get the most i can out of it. i have heard that others have signifigantly reduced the PE...but i too would like some real facts.

#30 dvb

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Posted 03 June 2009 - 03:25 PM

My EQ6 is working fine - the temptation to overhaul for me is the reports of finding surprises inside like metal shavings or poor greasing.

I did take the bottom part of my mount apart (the alt-azimuth pivots and pressure plate), and it looked pretty good. So, I'll hope the RA/Dec bearings are also good, and leave well-enough alone.

#31 Brodie

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Posted 03 June 2009 - 05:09 PM

a report at the eqmod yahoo group shows a pe reduction from 18.5 arcsecs down to about 8 with bearing replacement. guided, looks like it is at .5 arc secs...wonder what you would get guided before an overhaul?



#32 rmollise

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Posted 03 June 2009 - 05:13 PM

a report at the eqmod yahoo group shows a pe reduction from 18.5 arcsecs down to about 8 with bearing replacement. guided, looks like it is at .5 arc secs...wonder what you would get guided before an overhaul?


What do I get? Nice round stars with the C8 at f/6.3, and that is good enough for me. My suggestion to most ever'body is TRY THE MOUNT FIRST before you start poking around, and, again, maybe do something that makes it worse.

#33 Rusty

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Posted 03 June 2009 - 10:12 PM

"Amen" to what Uncle Rod says - especially if you're not mechanically inclined and don't have the tools and workspace to deal with the unexpected. The Atlas/Sirius EQ-Gs have been improving over the past few years. Even though I'm capable of "underhauling" (messin' with it when it ain't broke) my Sirius EQ-G, it works.

#34 groz

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Posted 03 June 2009 - 10:37 PM

a report at the eqmod yahoo group shows a pe reduction from 18.5 arcsecs down to about 8 with bearing replacement. guided, looks like it is at .5 arc secs...wonder what you would get guided before an overhaul?


What you get with the guider running depends on a lot of things. I dont have a precise measurement, but, I have an example. 3 tiny cuts in this frame, all from the same star group. 8 inch SCT, canon 350 prime focus, riding on the eq6, guided with the kwiq (qhy5 in the 9x50 finder). Guider was running with 1 second exposures, seeing was average for our part of the world (poor for the rest of the world). Top left, 1 minute, unguided. Top right, 1 minute, guided. Bottom, 5 minutes guided. All are clipped directly from the raw frames, no processing of any kind except to magnify a bunch to get a detailed look.

That's a stock eq6-pro, and in my opinion, it aint broke, and it's certainly not worth trying to 'fix' it, far to much potential to turn those lovely round stars into footballs, or, worse yet, 'box of parts' on the swap and shop table.

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#35 Charlie Hein

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Posted 03 June 2009 - 11:03 PM

What drives so many folks to consider overhauling the EQ6 mounts? Is the PE in these mounts frequently too "rough" to guide out? Some say they work great when guiding but many seem to not be satisfied. Tough to weed through anecdotal evidence vs. real facts.


I really think it's the quest to make it "just a little better" that causes most of the grief. I did a lot of stuff to my Atlas. I think that at the end of the day, aside from the Synscan upgrade there was nothing else that really *needed* to be done to make the mount really workable as an imaging platform. Do not be mislead by this statement - the new owner of my mount is definitely getting the benefit of my efforts and the mount still performs amazingly well. That said, the amount of effort and cost required to get it there IMO did not track well against the results. I believe that most folks would be quite satisfied leaving things as is as long as there are no glaring errors to correct.

So my advice is to do just that - work with the mount to determine if there are problems in need of a fix. If you find them then do exactly whatever it takes to fix the issue and resist the urge to do more at all costs.

#36 veil

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Posted 07 June 2009 - 07:14 AM

Just to put it out there with my experience, I was having eggy star problems at 1800fl on my eq6. I decided to check the ra worm for smoothness, so I pulled the ra motor out and I COULD NOT get the worm spur gear to turn by hand. Period. I backed off the worm meshing and then things got real easy. I set the preload and I am having some good success at 1.8 meters fl.

I don't know how long the ra motor would have lasted with the almost locked worm from the factory.

Maybe prevention is better than cure?

#37 Charlie Hein

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Posted 07 June 2009 - 07:40 AM

Just to put it out there with my experience, I was having eggy star problems at 1800fl on my eq6. I decided to check the ra worm for smoothness, so I pulled the ra motor out and I COULD NOT get the worm spur gear to turn by hand. Period. I backed off the worm meshing and then things got real easy. I set the preload and I am having some good success at 1.8 meters fl.

I don't know how long the ra motor would have lasted with the almost locked worm from the factory.

Maybe prevention is better than cure?


I'd say that you did exactly what I'm suggesting - and it worked for you...

  • you had a problem you could quantify
  • you had a good theory about what might be causing it
  • you did only what was necessary to fix it

The important take away from this is that you resisted the urge to "fix" the problem by pulling the mount completely apart and reworking everything. It turned out that all you needed to do was make some adjustments to loosen the binding. It didn't require major surgery to fix the problem - basic adjustments like worm mesh setting are things that I would consider to be routine maintenance and tuning anyway.

There are some very good reasons to do a teardown, no question about it - and some folks enjoy doing this as a part of the hobby, and there's nothing wrong with that. I'm just saying that in the vast majority of cases it really isn't necessary to tear the mount apart to get good performance from it.

#38 rmollise

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Posted 07 June 2009 - 08:51 AM

[I'd say that you did exactly what I'm suggesting - and it worked for you...

  • you had a problem you could quantify
  • you had a good theory about what might be causing it
  • you did only what was necessary to fix it


Egg-zactly! If there is a problem, and the user is mechanically competent, sure, there's no reason not to take a look at the mount. Tearing down a brand-new mount that's never had first light, though? Recipe for "Worked better before I fixed it." :lol:

#39 Rusty

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Posted 07 June 2009 - 08:29 PM

"If it ain't broke, fix it until it is!"

#40 John Carruthers

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Posted 08 June 2009 - 02:20 AM

I saw one 'fixed beyond repair' :foreheadslap: everyone who saw it on the bench just said "...why did he do that?". (it involved a half round file i believe).

#41 Rudy Nix

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Posted 09 June 2009 - 02:31 PM

I just finished overhauling my atlas mount. Now it is "more better".






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