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  #21  
Old 15-01-2021, 06:43 AM
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The_bluester (Paul)
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Balancing the AZEQ is always a bit tricky due to how the clutches work (AZEQ6 and EQ6 have totally different clutch designs)

The weight of the equipment and counterweights is sitting on top of the Dec clutch when the mount is set with counterweights down and it will make the clutch drag. To balance the Dec you need to release the clutch and rotate the mount so that the counterweights are slightly up (Above the RA axis) and you will probably find that the Dec axis suddenly frees up and becomes easy to balance. The RA is harder as you can't tip the axis down to take the weight off the clutch. I just balance it by pushing on the counterweight with one finger and trying to judge if it takes the same amount of force to get the RA to move both ways. I doubt it would drop far enough but if you could lower the altitude adjustment far enough to get the RA to point slightly downward it might free that clutch too. Now I have thought of that I may give it a try. When imaging I sit mine on a pier so if it works I could just shim the pier plate on the north side to allow the RA to be lowered below the horizontal for balance.

I am getting about 0.7-0.8" guiding out of my Orion Atlas AZEQ6 clone regularly.
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  #22  
Old 15-01-2021, 08:48 AM
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The_bluester (Paul)
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Thought I would add this in, I went out and made the experiment this morning. By dropping the altitude adjustment as low as it will go it does make the RA balance a lot easier to do. Raising the north side of the tripod to a scary position (Likely to over balance) makes it move as freely as the Dec does when putting the weights above the RA.

Not really practicable to do on my pier, it would take too much shimming of the pier plate, but dropping the altitude to 0 does make a significant difference by itself and would only add a minute or so to the balancing exercise to drop the alt to 0, balance the RA then raise the alt back to a known starting point for polar alignment.

Last edited by The_bluester; 15-01-2021 at 09:37 AM.
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  #23  
Old 15-01-2021, 09:24 AM
RugbyRene (Rene)
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Originally Posted by The_bluester View Post
Thought I would add this in, I went out and made the experiment this morning. By dropping the altitude adjustment as low as it will go it does make the RA balance a lot easier to do. Raising the north side of the tripod to a scary position (Likely to over balance) makes it move as freely as the Dec does when puttign the weights above the RA.

Not really practicable to do on my pier, it would take too much shimming of the pier plate, but dropping the altitude to 0 does make a significant difference by itself and would only add a minute or so to the balancing exercise to drop the alt to 0, balance the RA then raise the alt back to a known starting point for polar alignment.
Thanks. I'll try that today.
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  #24  
Old 15-01-2021, 12:58 PM
RugbyRene (Rene)
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So I applied some grease to the azimuth and altitude bolts. Azimuth is fine and moves nice and smooth (it always did but thought I'd apply some grease for good measure).

The altitude bolt is another matter. Applied the grease and made sure it was evenly distributed along the screw. Problem is the tightness/jerkiness when turning the bolt is still there. I did some investigation and have found that if I lift the mount from the counter-weight bar, there is significant play (up to a degree). If I then apply load to the mount (by putting the counter-weights on) it looks as if the added pressure causes the teeth bind and this is what causes the stiff/jerky movements. If I lift from the counter weight it releases this pressure and on the bolt and it turns smoothly.

So this is either a design fault or my mount has an issue that needs to be looked into.

If anyone else has an AZEQ6 could you have a look and see if yours does the same thing? Just lift the mount from the counter-weights and see if you have any play.

Rene
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  #25  
Old 15-01-2021, 01:09 PM
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xa-coupe (Jeff)
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Originally Posted by RugbyRene View Post
So I applied some grease to the azimuth and altitude bolts. Azimuth is fine and moves nice and smooth (it always did but thought I'd apply some grease for good measure).

The altitude bolt is another matter. Applied the grease and made sure it was evenly distributed along the screw. Problem is the tightness/jerkiness when turning the bolt is still there. I did some investigation and have found that if I lift the mount from the counter-weight bar, there is significant play (up to a degree). If I then apply load to the mount (by putting the counter-weights on) it looks as if the added pressure causes the teeth bind and this is what causes the stiff/jerky movements. If I lift from the counter weight it releases this pressure and on the bolt and it turns smoothly.

So this is either a design fault or my mount has an issue that needs to be looked into.

If anyone else has an AZEQ6 could you have a look and see if yours does the same thing? Just lift the mount from the counter-weights and see if you have any play.

Rene

You don't need to grease the entirety of the altitude bolts, just the parts that will be in contact with the thread in the mount. This requires you to unscrew the bolts way out whilst you keep an idea on which part actually sits in the threaded part of the mount body.



As for the play, have you ensured that the opposing bolt is snugged up to take up any slack, plus you need to ensure that the screw that attaches the mount to the tripod/pier is actually tight too .. there's a few things that can cause play... as well as the possibility of a problem with the mount itself.
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  #26  
Old 15-01-2021, 01:15 PM
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Quote:
Originally Posted by xa-coupe View Post
You don't need to grease the entirety of the altitude bolts, just the parts that will be in contact with the thread in the mount. This requires you to unscrew the bolts way out whilst you keep an idea on which part actually sits in the threaded part of the mount body.



As for the play, have you ensured that the opposing bolt is snugged up to take up any slack, plus you need to ensure that the screw that attaches the mount to the tripod/pier is actually tight too .. there's a few things that can cause play... as well as the possibility of a problem with the mount itself.
Yeah I might've gone a bit over board with the grease but that's fine.

I've tightened the opposing bolts but it still moves. And I've ensured the mount is securely attached to the tripod. It's pretty obvious where the play is. I suspect it's a design flaw with the AZEQ6 or my mount is faulty. It's going for a service at Bintel in 2 weeks so I'll mention that as well.

Rene
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  #27  
Old 15-01-2021, 01:19 PM
RugbyRene (Rene)
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Well it looks like the play is intentional. This is from the manual:

Note: It is normal to have slight elevation play on the AZ-EQ6 GT mount. The mount depends
on the gravity of its payload and its own weight to stay fi rm. Because of this, it is recommended
to end the elevation adjustment with an upwards movement. Whenever there is an upwards
over-adjustment, lower the elevation first, and then jack the mount upwards again.
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  #28  
Old 15-01-2021, 01:38 PM
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multiweb (Marc)
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Originally Posted by RugbyRene View Post
Well it looks like the play is intentional. This is from the manual:

Note: It is normal to have slight elevation play on the AZ-EQ6 GT mount. The mount depends
on the gravity of its payload and its own weight to stay fi rm. Because of this, it is recommended
to end the elevation adjustment with an upwards movement. Whenever there is an upwards
over-adjustment, lower the elevation first, and then jack the mount upwards again.
Yeah that's pretty standard to any mount. There are a lot of similar things you do in astro to preload weight and take up backlash. Like focusing a heavy SCT by pushing the mirror upwards for the last tweak or loading the worm east on an EQ mount. That's no different. You push your elevation up against gravity.
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  #29  
Old 15-01-2021, 09:00 PM
Startrek (Martin)
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So I went to Bintel and can't have it serviced until the first week of Feb as Don is snowed under at the moment. That's fine. I'll wait.

Until then I have another question. When I'm polar aligning and adjusting the altitude bolt, it is really stiff to turn which makes fine adjustments very hard (I end up over-shooting as I need to apply additional force). When I take the load off the bolt moves smoothly. I weighed my scope and it comes in at 12kg, well inside the upper load limit of the mount which is 20kg.

Could I apply some lubricant to aid in making it easier to turn?

Rene
When you look at the Skywatcher website or look the 2019 Skywatcher brochure, the max payload of the AZEQ6 is 22kg
From my understanding this rating is not de rated or adjusted for long exposure Astrophotography
I’ve always adhered to the recommended 65% factor when determining your mount payload rating for long exposure Astrophotography
I could be totally incorrect but using the general rule of thumb ( 65% factor ) the AZEQ6 would have a recommended long exposure Astrophotography max payload rating of 14.5kg
Both my EQ6-R mounts have a Skywatcher max payload rating of 22kg so therefore a recommended long exposure Astrophotography max payload rating of 14.5kg
I’ve weighed my rig at my dark site and it comes in at 14.5kg ( 8” f5 newt including all the ancillary Astro imaging gear )
On good stable nights my guiding in Dec is around 0.50 to 0.60 arc sec error and RA around 0.70 to 0.80 arc sec error.
I’m confident that I couldn’t achieve the above guiding error with another 7kg on board ( ie with the Skywatcher 22kg of payload on board my mount )
I welcome any comments in regards to AP payloads
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  #30  
Old 15-01-2021, 09:02 PM
raymo
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If you look at how close the altitude bolt is to the pivot point, it should become obvious that the leverage applied by the counterweights is enormous.
Any bolt put in that situation would be very difficult to turn when increasing
the altitude. Just as has been said, take most of the weight by lifting the
counterweight shaft, and the bolt will last indefinitely, even if unlubricated.
raymo
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  #31  
Old 16-01-2021, 11:26 AM
RugbyRene (Rene)
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If you look at how close the altitude bolt is to the pivot point, it should become obvious that the leverage applied by the counterweights is enormous.
Any bolt put in that situation would be very difficult to turn when increasing
the altitude. Just as has been said, take most of the weight by lifting the
counterweight shaft, and the bolt will last indefinitely, even if unlubricated.
raymo
But if I’m doing fine adjustments during PA lifting the counter weight load moves the mount by 1 degree so it will make it hard to get an accurate PA. To me it seems like a design flaw and the explanation in the manual is post-hoc reasoning.

Rene
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  #32  
Old 16-01-2021, 12:13 PM
raymo
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You don't lift it, you take most of the weight, so that the bolt can easily make minor adjustments. I've been using EQ mounts with similar adjusting mechanisms for nearly 68 years with no problems. Up market mounts can have better systems, but that is part of the substantially higher price of such
mounts.
raymo
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  #33  
Old 17-01-2021, 07:10 AM
RugbyRene (Rene)
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Ok so I managed to get out last night and do some imaging. Wasn't the most successful night and there are some issues I need to diagnose:

1. Guiding - Total RMS didn't get below 1.5, & it moved between approx. 1.5 & 3.5 pretty consistently all night. I analysed the graph this morning and my RA graph was sinusoidal, not at all flat. DEC was fine. My PA was good, and I balanced both RA and DEC pretty well. Could this be back-lash in the RA axis? If so how do I get rid of it?

2. Star shape - I suspect this is related to my RA issue in point 1. On inspecting my images I noticed that I had egg shaped stars. It was across the entire image and was vertical in nature (i.e. egg shaped from top to bottom). Now I don't think it was tilt as the amount of "egginess" varied. That is some were worse than others.

So all in all not the most successful night but hey it's all a learning experience.

Any help would be greatly appreciated.

Rene
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  #34  
Old 17-01-2021, 07:47 AM
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Do you have PEC installed? If the errors are sine wave shaped then that is what a PEC curve usually looks like.
PEC makes a considerable difference to guiding results. I use Pempro.

PHD2 is quite a good autoguiding program. I read that it now offers multiple star autoguiding to help beat the seeing.

Seeing last night was not as good as a few nights ago.

Egginess across the image is guiding errors. Tilt is one or two corners with poor stars.

Greg.
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  #35  
Old 17-01-2021, 07:59 AM
RugbyRene (Rene)
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Originally Posted by gregbradley View Post
Do you have PEC installed? If the errors are sine wave shaped then that is what a PEC curve usually looks like.
PEC makes a considerable difference to guiding results. I use Pempro.

PHD2 is quite a good autoguiding program. I read that it now offers multiple star autoguiding to help beat the seeing.

Seeing last night was not as good as a few nights ago.

Egginess across the image is guiding errors. Tilt is one or two corners with poor stars.

Greg.
Hi Greg,

Thanks for that. I don't have PEC installed or PemPro.

I can never seem to get PHD2 to calibrate properly. I use the internal guider in Kstars which has been pretty good in the past.
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  #36  
Old 17-01-2021, 10:41 AM
raymo
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Have you got your rig balanced a little against the drive, that pretty much eliminates backlash, and is normal practice.
raymo
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  #37  
Old 17-01-2021, 11:08 AM
RyanJones
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Raymo is right. If you balance slightly east heavy the worm and gear will stay meshed instead of bouncing between the teeth. However removing as much backlash as is safe to do so will limit the amount of influence backlash has. It’s all a game of how much time you want to put into tuning your setup. Search for astrobaby’’s eq mount tuning and there’s a pretty good run down on how to make the adjustments. Just try to spend the time to understand what you are doing and why. Over time it makes it much easier to diagnose issues and get the most out of your setup.
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  #38  
Old 17-01-2021, 12:39 PM
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The_bluester (Paul)
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If it is slowly oscillating in RA it is probably an issue with settings in PHD2. Backlash in RA is not generally an issue as the RA does not reverse like the Dec does. At maximum guiding rates (1X) guiding east stops the RA completely and guiding west runs it at 2X sidereal rate. What issues are you having in calibration? If it does not calibrate properly you may be in for trouble all night.


Regards the altitude bolt, My payload is not particularly heavy and the bolt is a little stiff when raising the RA, as was mentioned previously, there is quite a bit of mechanical advantage between the weight on the mount and the alt bolt. And yes, there is play in altitude but it should not make any difference once you are polar aligned, if you fiddle around and remove the scope or something else that jostles the mount it would be wise to check the PA again as it may not come to rest in quite the same place if you take the pressure off the alt bolt.
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  #39  
Old 17-01-2021, 12:43 PM
Startrek (Martin)
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I’m pretty sure the new AZEQ6 mounts are belt driven like my two EQ6-R so backlash is minimal out of the box
I just tweaked the worm adjustments ever so slightly on my EQ6-R to eliminate the small amount of Dec play and it’s running beautifully. The drive belts didn’t need any adjustment at all, and still haven’t after 2 years of use
I don’t know if Rene has an older model or newer belt driven model AZEQ6 ??
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  #40  
Old 17-01-2021, 12:43 PM
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Quote:
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If it is slowly oscillating in RA it is probably an issue with settings in PHD2. Backlash in RA is not generally an issue as the RA does not reverse like the Dec does. At maximum guiding rates (1X) guiding east stops the RA completely and guiding west runs it at 2X sidereal rate.


What issues are you having in calibration? If it does not calibrate properly you may be in for trouble all night.
I don't use PHD2 as I've never been able to get it working despite watching numerous vides. I use the internal guider in KStars which is able to calibrate and guide.
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