Rudy Nix
member
Reged: 03/19/08
Loc: Hollister,CA
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Re: Atlas overhaul...stop me before its too late!
[Re: mtb.daily]
#3133928 - 05/29/09 10:30 AM
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I have found that there are a lot of hardware items used in astronomy and astrophotography equipment, when purchased from someplace other than a retailer dedicated to astrnomy and astrophotographic equipment, to be almost half the price for an identical item. On one site that sold this bearing, the listed price was $47.00 just for the one bearing. Unfortunatly, the place I ordered the SKF 32208 J2/Q bearing from has them on backorder. I'm willing to wait until they are in stock, especially since they're price is only $27.00.
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mtb.daily
sage
Reged: 09/19/07
Loc: Toronto, Ontario, Canada
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Re: Atlas overhaul...stop me before its too late!
[Re: Rudy Nix]
#3134160 - 05/29/09 12:49 PM
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The patient process.... Hmmm....... wait.... wait..... wait.....Nope, not for me.
I'll spend the $$$$ and call to be sure they are in stock..... But, thats just me.
Edited by mtb.daily (05/29/09 12:50 PM)
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groz
Carpal Tunnel
Reged: 03/14/07
Loc: Campbell River, BC
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Re: Atlas overhaul...stop me before its too late!
[Re: rmollise]
#3134306 - 05/29/09 02:11 PM
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"The Only Enemy of Good Enough is More Better."
Truer words were never spoken.
We have an eq6-pro, and an heq5-pro. My eq6 has for the last 6 months carried the C8 in a side by side bar, with the ST80 beside it for guiding. Our heq5 carries a williams 80, and we've got the Kwiq guide system on it (qhy5 in a 9x50 finder). That kwiq works fabulously with this combination, so much so, I decided to try it with the c8.
This last weekend, I removed the side by side setup, and put the kwiq onto the c8. With the focal reducer in the c8, shooting with a canon 350, I got pinpoint perfect stars with this combination too.
Would a tear down/rebuld help either of our kits? I dont think so, they already perform admirably for photography. Would it hurt them ? Maybe, maybe not. I'm not the most mechanically inclined, so, in my case, it's far more likely to hurt rather than help. It aint broke, so, there's nothing to fix, and lots to break.
But, this whole conversation reminds me of a stop at the swap and shop tables at the Table Mountain Star party a couple summers ago. I didn't have the EQ6 yet, and was in the market for a beefier eq mount. One fella had an atlas for sale, but, on close inspection, turned out to be his 'atlas project', complete with 'box of parts left over' after a teardown / put together attempt. That didn't leave me with a warm fuzzy, and I left it sitting on the swap table.
Point of the comments, if you are at all unsure of 'fixing' your mount that is apparently 'not broken', ask yourself how much of a disaster would it be to end up with 'box of parts leftover', and trying to pawn it off at a swap table ? If that would be a dire hardship for you, I'd seriously consider the idea of leaving well enough alone.
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John Carruthers
Skiprat
Reged: 02/02/07
Loc: Kent, UK
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Re: Atlas overhaul...stop me before its too late!
[Re: Brodie]
#3135264 - 05/30/09 03:29 AM
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how do you know when youve got the "worm engagment/mesh adjustment" right....is it ajust/put back together/track/tear down/adjust....ect?
2 ways; by feel using years of experience and unerring skill, or hook up a meter and watch the current draw, when it spikes back off a hair.
Once set let it rest for a few minutes then try a full rotation by hand, amazing how much they relax and how much spring there is in the castings.
It's worth persevering to get it as perfect as you can. That way you may never need to do it again. Get that worm fixed lonways, then centred over the wheel, then the mesh depth right. I've seen one that although only a few thou off centre had worn its own 'hog' into the wheel :-(
I would avoid over greasing tapered roller bearings, they're not car wheel bearings and don't need packing as you would for auto aplications, they only go round once a day. The ends need most lube, the sides need to roll along the race not slide. A little pre-load can be good but only a little.
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Brodie
member
Reged: 05/28/08
Loc: Washington, La.
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Re: Atlas overhaul...stop me before its too late!
[Re: John Carruthers]
#3136721 - 05/30/09 11:48 PM
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i decided to wait atleast until i have a chance to see how it performs with a guide scope. i do think i want to lighten the load with a smaller OTA to help with sturdiness and allow for more accessories....(dang aperture fever).
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Dwight J
sage
Reged: 05/14/09
Loc: Lethbridge, Alberta, Canada
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Re: Atlas overhaul...stop me before its too late!
[Re: dvb]
#3142200 - 06/02/09 05:15 PM
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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
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Tim C
scholastic sledgehammer
Reged: 11/11/07
Loc: Marietta, GA
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Re: Atlas overhaul...stop me before its too late!
[Re: Dwight J]
#3143410 - 06/03/09 11:23 AM
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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.
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Bob D
sage
Reged: 05/24/08
Loc: Dallas, Texas, USA
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Re: Atlas overhaul...stop me before its too late!
[Re: Tim C]
#3143788 - 06/03/09 02:45 PM
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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.
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Brodie
member
Reged: 05/28/08
Loc: Washington, La.
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Re: Atlas overhaul...stop me before its too late!
[Re: Bob D]
#3143851 - 06/03/09 03:20 PM
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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.
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dvb
different Syndrome.
Reged: 06/18/05
Loc: Vancouver, Canada
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Re: Atlas overhaul...stop me before its too late!
[Re: Brodie]
#3144001 - 06/03/09 04:25 PM
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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.
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Brodie
member
Reged: 05/28/08
Loc: Washington, La.
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Re: Atlas overhaul...stop me before its too late!
[Re: dvb]
#3144169 - 06/03/09 06:09 PM
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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?
Edited by Brodie (06/03/09 06:12 PM)
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rmollise
Postmaster
Reged: 07/06/07
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Re: Atlas overhaul...stop me before its too late!
[Re: Brodie]
#3144179 - 06/03/09 06:13 PM
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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.
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Rusty
Postmaster
Reged: 08/06/03
Loc: Brooker, FL
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Re: Atlas overhaul...stop me before its too late!
[Re: rmollise]
#3144682 - 06/03/09 11:12 PM
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"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.
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groz
Carpal Tunnel
Reged: 03/14/07
Loc: Campbell River, BC
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Re: Atlas overhaul...stop me before its too late!
[Re: Brodie]
#3144716 - 06/03/09 11:37 PM Attachment (36 downloads)
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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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Charlie Hein
Postmaster
Reged: 11/02/03
Loc: 26.06.08N, +80.23.08W
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Re: Atlas overhaul...stop me before its too late!
[Re: Tim C]
#3144752 - 06/04/09 12:03 AM
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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.
Edited by Charlie Hein (06/04/09 12:08 AM)
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veil
journeyman
Reged: 04/20/08
Loc: Bathurst Australia
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Re: Atlas overhaul...stop me before its too late!
[Re: Charlie Hein]
#3150025 - 06/07/09 08:14 AM
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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?
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Charlie Hein
Postmaster
Reged: 11/02/03
Loc: 26.06.08N, +80.23.08W
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Re: Atlas overhaul...stop me before its too late!
[Re: veil]
#3150051 - 06/07/09 08:40 AM
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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.
Edited by Charlie Hein (06/07/09 08:43 AM)
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rmollise
Postmaster
Reged: 07/06/07
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Re: Atlas overhaul...stop me before its too late!
[Re: Charlie Hein]
#3150107 - 06/07/09 09:51 AM
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[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." 
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Rusty
Postmaster
Reged: 08/06/03
Loc: Brooker, FL
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Re: Atlas overhaul...stop me before its too late!
[Re: rmollise]
#3151265 - 06/07/09 09:29 PM
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"If it ain't broke, fix it until it is!"
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John Carruthers
Skiprat
Reged: 02/02/07
Loc: Kent, UK
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Re: Atlas overhaul...stop me before its too late!
[Re: Rusty]
#3151666 - 06/08/09 03:20 AM
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I saw one 'fixed beyond repair'  everyone who saw it on the bench just said "...why did he do that?". (it involved a half round file i believe).
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