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Atlas EQ-G Tracking Question

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#1 Trebor777

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Posted 06 April 2009 - 01:45 AM

When I put in my 12.5mm illuminated recticle EP and put Saturn in the middle square and line up the lines so they're parralell with the rings, Saturn drifts to the left (RA) and within 30-45 seconds is totally outside of the square, but still in the lines. Are my RA gears misaligned? Or is it as simple as not being exactly Polar aligned.

Oh yeah, I started with a 3 star align; Sirius, Mirfak & Arcturus. My Goto's were almost spot on and I thought I had Polar alignment pretty good. I did perform the Hypertune and have put all new bearings in the mount. The RA is a little tight when I turn it. - And no, it's not because I tightened the collar that holds the RA tapered bearing in place too tight. The RA ring gear was a *BLEEP* to get back into the RA housing - but I figured this didn't mean too much because the RA is supposed to be totally tightened when tracking/observing/using the mount. But the one issue I have with the RA being tight is balancing the OTA and counterweights.

I'm hopeing it's as simple as a bad polar alignment...

It's not bad for visual observing, but when I start astrophotography it'll be an issue...

Thanx in advance.

#2 rmollise

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Posted 06 April 2009 - 07:28 AM

It's not bad for visual observing, but when I start astrophotography it'll be an issue...

Thanx in advance.


Yes, poor polar alignment can cause RA drift...but...that tightness in RA (with the lock off) doesn't sound good to me.

#3 Trebor777

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Posted 06 April 2009 - 11:52 AM


It's not bad for visual observing, but when I start astrophotography it'll be an issue...

Thanx in advance.


Yes, poor polar alignment can cause RA drift...but...that tightness in RA (with the lock off) doesn't sound good to me.


Well, could that tightness be causing theh RA drift? That's my main concern.

The RA is locked when using the mount, so "I figured" (meaning, I might be wrong) that wasn't the issue with it being tight.

The gears sound great (alot better then before I hypertuned it). The GoTo's are spot on. And I haven't had an alignment failure. There's only a RA drift.

#4 Mert

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Posted 06 April 2009 - 12:20 PM

Which version of stepper controller do you have
in your mount?
You can check this by starting EQMOD and copying
the text from the message center.
I seem to remember that if you have version 1.06 you
must put the ra-drift compensation ( right hand
side of the main menu ) to 3.

Edit: Oops, I simply asumed you are using EQMOD, but you
didn't state that!

Hope that helps you,

#5 rmollise

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Posted 06 April 2009 - 12:33 PM


Well, could that tightness be causing theh RA drift? That's my main concern.

The RA is locked when using the mount, so "I figured" (meaning, I might be wrong) that wasn't the issue with it being tight.

The gears sound great (alot better then before I hypertuned it). The GoTo's are spot on. And I haven't had an alignment failure. There's only a RA drift.


Maybe. Tighten up your polar alignment, and, as has already been said, if you're using a mount with the affect MCB version and are using EQMOD, you need to set drift compensation to "3."

;)

#6 Trebor777

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Posted 06 April 2009 - 01:02 PM

I am not using EQMOD - but I should be...lol. I've downloaded the ASCOM drivers and all that fun stuff, I've just been to lazy to mess with it. Plus, I don't have a CCD camera right now so I haven't been taking out my laptop with me when I observe. Is the EQMOD easy to set up?

And knowing that I haven't been using EQMOD, does this mean that the ra drift compensation is correct? Or is that something that can only be set w/ EQMOD?

My other option is to order a new RA housing from orion - but I don't want to do that. The gears and bearings are fine.

When I originally put everything back together, I was almost finished and then I noticed that I had the RA setting circle upside down. So, I went to pull the whole thing out of the RA housing. When I did I guess I wasn't exaclt straight and the ring gear got stuck at a little angle and I had to, kinda muscle it out. I'm thinking I might have made the edge of the inside of the RA housing a little off = making the RA tight and not totally flush.

But, it's not horrible. It's not super tight. The mount works, sounds better and everything is on target.

Would you guys suggest that I take it apart and have a look-see inside the RA housing also? Maybe put a little more lube on the ring gear then I already did?

I've rebuilt 3 Atlas EQ-G's and of course mine is the one with the issue. Murphy's Law. Though the issue coudl jsut be polar alignment and I'm worried about nothing.

#7 Mert

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Posted 06 April 2009 - 01:32 PM

Ok, if you've got a simple webcam, why don't you
just hook that up to some of your OTA's and run
PErecorder for some 5 cycles.
Then post or even better, upload your results to the
temp folder on the eqmod group.
Maybe we can see if there's something odd in your mount.
To me right now it simply sounds like a not too
well done polar alignment.

Just my :penny: :penny: :shrug:

#8 Trebor777

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Posted 06 April 2009 - 01:37 PM

Wanna know what I just realized? I never made sure my polar scope was aligned in the RA shaft after putting everything back together. :foreheadslap: :tonofbricks:

So, I'm thinking I'm polar aligned, but I'm not cause the mount is pointing somewhere different then where the polar scope is.... Doh!!!

But I still don't like the tightness. It makes it harder to balance.

#9 Mert

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Posted 06 April 2009 - 01:50 PM

Oh yes, that will make a lot of difference!
Well done!

Enjoy!

#10 jrbarnett

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Posted 06 April 2009 - 02:33 PM

Hmm...for visual use I find the polar scope to be nearly irrelevant. In fact, you can get good results removing the polar scope and sighting through the empty bore hole. I've never bothered to align my polar scope and find that centerig Polaris plus a two star alignment keep GOTO slews in the field of a medium power eyepiece pretty much all night.

Go ahead and align your polar scope, but if that doesn't fix matters, suspect something amiss with the RA rebuild.

Regards,

Jim

#11 Trebor777

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Posted 07 April 2009 - 08:32 PM

Hmm...for visual use I find the polar scope to be nearly irrelevant. In fact, you can get good results removing the polar scope and sighting through the empty bore hole. I've never bothered to align my polar scope and find that centerig Polaris plus a two star alignment keep GOTO slews in the field of a medium power eyepiece pretty much all night.

Go ahead and align your polar scope, but if that doesn't fix matters, suspect something amiss with the RA rebuild.


Visual is fine. GoTo's are right on.

There was just a little RA drift. Which when doing astrophotography will not be very good.

Polar aligning takes me less the 2 minutes, so it's not a bother at all. I just wasn't "actually" polar aligned...which I realized after I posted here.

Plus when I wasn't using the cross hairs I didn't even notice the RA drift. I'm willing to bet once I align the polar scope that RA drift disappears. I'll let people know...

Oh yeah, I'm picking up a CGE on Thursday!!! Got to move from a 40# capacity up to a 65# capacity.

Notice of Edit: edited language - this is a family friendly board. CH

#12 rmollise

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Posted 08 April 2009 - 07:11 AM

I am not using EQMOD - but I should be...lol. I've downloaded the ASCOM drivers and all that fun stuff, I've just been to lazy to mess with it. Plus, I don't have a CCD camera right now so I haven't been taking out my laptop with me when I observe. Is the EQMOD easy to set up?

And knowing that I haven't been using EQMOD, does this mean that the ra drift compensation is correct? Or is that something that can only be set w/ EQMOD?


Yes, but this is only a problem when using EQMOD, and only for some versions of the MC board...

#13 Trebor777

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Posted 30 April 2009 - 05:53 PM

OK, I finally got around to getting back inside the Atlas to see why the RA was so tight (unlocked) when I turned it.

I took the RA apart adjusted the worm gear a little, made sure all the bearings/spacers where fully in place. Everything checked out and spun freely. So, I put everything back together - No more tightness in the RA!!!

But wait, now when the RA is loose, I can't lock the RA. I have the bolt in place correctly, with the brass pad. So, I did a little adjustment and then I got it to work and the RA locked....BUT...now the RA is stiff again when I turn it (unlocked).

So, I can have a nice smooth turning RA, but it wont lock - or I have an RA that will lock, but it's stiff.

Any ideas???? I was just in my shop in the basement for an hour adjusting the screws and bolts on the RA and got tired, so I found my oild thread. Hopefully someone has some ideas as to why I can't have both a free turning RA and have it locked???

The mount works when it's stiff, but I'm trying to get this Atlas ready to sell and while the RA works it's a bit stiff and I want to have it spin freely like it should.

Thanx in advance...

#14 DugDog

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Posted 30 April 2009 - 11:11 PM

Hi Randy,

To address polar alignment...
I use "Polarfinder Scope" by Jason Dale.

If you have never used this software program, it instantly shows you where polaris should be at the exact moment in time. I don't go anywhere with out it.

I have no suggestions for your Atlas tear down.

DD

#15 Trebor777

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Posted 01 May 2009 - 12:42 AM

Polar alignment is fine. I'm just having issues with the RA lock.

#16 Time on my hands

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Posted 01 May 2009 - 02:16 AM

Randy, I have been on the verge of rebuilding my Atlas all winter but something else always seems to get in line before it. However, I believe that there is a "felt" pad between the brass ring gear and the brass locking "bolt" that locks the axis in place. Brass on brass would not provide enough friction. I do not know what the pad is actually made of but it will look and feel something like felt. It may have come loose during reassembly and jammed up the works making it stiff then fell out when you reassembled it leaving the brass on brass situation you now seem to have.

EDIT: P.S. I have also seen pads made of a hard plastic pellet. I do not know what the Atlas actually uses but there is something in there.

#17 Trebor777

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Posted 01 May 2009 - 02:53 AM

Randy, I have been on the verge of rebuilding my Atlas all winter but something else always seems to get in line before it. However, I believe that there is a "felt" pad between the brass ring gear and the brass locking "bolt" that locks the axis in place. Brass on brass would not provide enough friction. I do not know what the pad is actually made of but it will look and feel something like felt. It may have come loose during reassembly and jammed up the works making it stiff then fell out when you reassembled it leaving the brass on brass situation you now seem to have.

EDIT: P.S. I have also seen pads made of a hard plastic pellet. I do not know what the Atlas actually uses but there is something in there.


I've taken apart and rebuilt and/or regreased 3 Atlas's. None had felt. All 3 were brass pad pressing against the brass ring gear. It's Murphy's Law, because the other ones I worked on weren't mine and I had zero hic-ups. Then I get to my own, and of course there's a hic-up.

I gotta mess around with getting the alignment right tomorrow. Something's off, I just can't figure out what. It's strange that I can have the RA free spining but not be able to lock it, but then I can adjust the RA so it locks, but it's somewhat stiff.

Thanx for the response....

#18 Time on my hands

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Posted 01 May 2009 - 02:53 PM

Randy,
The brass surprises me but it would explain why the locks have an all or nothing kind of feel. Also, since my RA is also stiff (Part of why I want to rebuild.) the solution to this riddle is of great interest to me. There is a member of CN that I have not seen in this thread that could know the answer, however, and you might send him a PM. His screen name is "Strgazr27". Please do not forget to let us know the answer if he knows it.

#19 DugDog

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Posted 01 May 2009 - 02:55 PM

Randy,

I have never rebuilt the mount before, however, I did find this link with a complete tear down:
http://www.beevo.com/rework.htm

Lots of cool photos of tear down, and reassembly. Maybe there is a photo of step you are over looking.

Worth a look?
:shrug:

DD

#20 Trebor777

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Posted 01 May 2009 - 04:03 PM

Randy,
The brass surprises me but it would explain why the locks have an all or nothing kind of feel. Also, since my RA is also stiff (Part of why I want to rebuild.) the solution to this riddle is of great interest to me. There is a member of CN that I have not seen in this thread that could know the answer, however, and you might send him a PM. His screen name is "Strgazr27". Please do not forget to let us know the answer if he knows it.


The reason for your RA being a little tight is probably the piece that the polar alignment scope screws into. If you unscrew the polar alignment scope, and then unscrew the 3 screws holding the cicle (with arrow) and take the piece off, you'll notice 4 tiny set screws - if you loosen those a bit, you can turn the black ring (which holds the bottom tapered RA bearing in place)counter clockwise just a little, and the retighten the 4 set screws and put everything back on.

EDIT: that black ring is usually REALLY TIGHT. I had to use big pliers and a rag to get it loose. But it's usually the reason for the RA being tight - just not in my instance.

Check here for images of what I'm talking about. Steps 15-18. It's actually Bobby's rebuild page.

Stargazer27 - Bobby, actually has my SN10 right now. He's finishing up a carbon fiber tube for it. I sent him a PM if he has any clues as to my issue. After dinner, I'm gonna run downstairs and work on it a bit more.

#21 Trebor777

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Posted 01 May 2009 - 04:07 PM

Randy,

I have never rebuilt the mount before, however, I did find this link with a complete tear down:
http://www.beevo.com/rework.htm

Lots of cool photos of tear down, and reassembly. Maybe there is a photo of step you are over looking.

Worth a look?
:shrug:

DD


Thanx, I've actually seen that page before. Bobby's page is a bit more detailed - which I posted a link in the previous post.

I've also watch TSS (Telescope Stability Systems) Atlas Hypertune DVD a couple of times - along with experience (3 rebuilds) of the Atlas.

I'm just miffed as to what my issue is now with the RA not locking but being smooth to turn or being able to lock, but tight.

Thanx for your replies, there greatly appreciated.

#22 Charlie Hein

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Posted 02 May 2009 - 07:32 AM

If I remember correctly, the clutch lock "bolt" screws into the housing of the mount and eventually contacts the side of the worm wheel to drive the mount. There's a hard stop on the housing that blocks the clutch "handle" from rotating all the way around and thus keeps the clutch bolt in place. The clutch bolt has a square "head". The handle has an eight point cutout in it to facilitate adjustment of the handle position.

If you tighten the clutch enough to engage it fully then remove the handle and move it a notch or so in the direction that you used to tighten the clutch, this should give you more clutch bolt travel in the opposite direction when you go to unlock it. I'd think that this would solve your problem, but the handle may look a little funny when locked down.

If it doesn't fix the problem then it's probably not the clutch that's binding the RA axis.

#23 mtb.daily

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Posted 03 May 2009 - 10:23 AM

Hey gang,

I just tried to order the DVD but Paypal states:

This recipient is currently unable to receive money.


Is TSS still doing business ?

-Jerry

#24 mtb.daily

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Posted 03 May 2009 - 10:24 AM


Is there another supplier of the DVD for the EQ6 mount?

#25 Trebor777

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Posted 03 May 2009 - 12:25 PM

Hey gang,

I just tried to order the DVD but Paypal states:

This recipient is currently unable to receive money.


Is TSS still doing business ?

-Jerry


I don't think so. Not 100% sure

Check this link though: Astro-Ruby-Lith

They're working on a DVD for the Atlas rebuild - AND they sell bearings, spacers, has a CW shaft upgraded for the Atlas. Bascially they're selling everything you need to rebuild the mount. That's where I got my bearings & spacers from. They're stepping in where TSS left. It's sad because TSS was good, but didn't take care of their customers. There were people who sent TSS a lot of money and got nothing in return and had to try to get their money back from Paypal.

I'd email A.R.L. about the DVD...






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