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Old 20-11-2017, 08:39 AM
E_ri_k (Erik)
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Guiding question/troubleshooting

So my guiding has been pretty flawless until recently. I have these random spikes appear in the declination. I have been troubleshooting it over the past few nights, with no great success.

Iím using PHD 2, and adjusting the parameters did not really do much good. Changing the guide mode between North and South made the spikes not appear as often, but they were still there.

One thing I did notice however was when I turned guiding OFF in declination the spikes did not appear at all!? And the RA graph was a lot smoother.

My plan now is to get my polar alignment good enough so I donít have to guide in DEC.

Thought would be appreciated.

Erik
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Old 20-11-2017, 08:41 AM
E_ri_k (Erik)
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I canít seem to post images of my graphs from my phone, so that may come later!
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Old 20-11-2017, 08:47 AM
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Merlin66 (Ken)
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Erik,
Notwithstanding the spikes - how do the images look??
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Old 20-11-2017, 10:01 AM
E_ri_k (Erik)
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Originally Posted by Merlin66 View Post
Erik,
Notwithstanding the spikes - how do the images look??
When the spike occurs there is a definite jump in the image (elongated stars in DEC ONLY) It is also very visible on the auto guider image. I know itís not, but itís like as if it is sending rougue commands to the mount!
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Old 20-11-2017, 03:33 PM
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What's first ? The spike or the correction command.

I thought my guiding did that but I soon realized that it was the mount as the spikes preceded the command steps. Cleaned out the mount and its better (well a bit anyway). There's a few really good guides on common problems eg
https://www.google.com.au/url?sa=t&s...q-qd2bYGZi_iQL
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Old 20-11-2017, 04:01 PM
E_ri_k (Erik)
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Quote:
Originally Posted by ChrisV View Post
What's first ? The spike or the correction command.

I thought my guiding did that but I soon realized that it was the mount as the spikes preceded the command steps. Cleaned out the mount and its better (well a bit anyway). There's a few really good guides on common problems eg
https://www.google.com.au/url?sa=t&s...q-qd2bYGZi_iQL
Hi Chris, it will spike rapidly, then correct for it (unsuccessfully) Were your spikes in DEC or the RA? I have been doing a lot of reading lately haha!

These are my guide graphs (in the wrong order) In he middle image I switched guiding OFF in DEC at the halfway mark (where the graph settles down) I didn't see any spikes for over 15 minutes...?

Erik
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Old 20-11-2017, 04:53 PM
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that_guy (Tony)
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same problem occured to my older eq6. I've learned to live with it and guide only in one direction. if someone has a solution id be very much greatful!
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Old 20-11-2017, 04:53 PM
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atalas
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Hi Erik

Mate,what mount do you have?look at your Dec balance....you need to balance Dec in vertical position as well as horizontal....can you imagine the leverage produced from even a slightly unbalanced Dec? you know....all those things hanging off one side of the scope.

If you Dec is balanced well It will be balanced in any position It points!

I cringe when I hear people saying unbalance your Dec to take up backlash

Yes,try and get you polar alignment as tight as you can....the further It's out the more problematic Dec cross talk becomes....and It's easy to see why.

Cables dude....has an impact....tidy those suckers.

Also,when the seeing is bad It becomes more difficult to diagnose....cause that means you spend your one night a year of good seeing stuffing around instead of imaging

Good luck and I'm sure you'll sought It.
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Old 20-11-2017, 05:31 PM
E_ri_k (Erik)
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Quote:
Originally Posted by atalas View Post
Hi Erik

Mate,what mount do you have?look at your Dec balance....you need to balance Dec in vertical position as well as horizontal....can you imagine the leverage produced from even a slightly unbalanced Dec? you know....all those things hanging off one side of the scope.

If you Dec is balanced well It will be balanced in any position It points!

I cringe when I hear people saying unbalance your Dec to take up backlash

Yes,try and get you polar alignment as tight as you can....the further It's out the more problematic Dec cross talk becomes....and It's easy to see why.

Cables dude....has an impact....tidy those suckers.

Also,when the seeing is bad It becomes more difficult to diagnose....cause that means you spend your one night a year of good seeing stuffing around instead of imaging

Good luck and I'm sure you'll sought It.
Thanks Paramount MX. Declination is balanced, and I have had all the cables through the mount for a while now. Im going to refine the alignment tonight.

I did notice one strange thing just now though..... While balancing the DEC, it feels a bit "tight" When balancing the RA, I can push it ever so lightly with my finger and it will freely move. The DEC is good up to a point, but then it feels like it sticks and will hold its position, even if unbalanced slightly. I have just given it a bit of a wiggle and seems to have freed up.....

I thought maybe the cable through the mount could be playing a part??

Erik
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Old 20-11-2017, 06:32 PM
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codemonkey (Lee)
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My guess is stiction; that's roughly what would happen with my old EQ6 when the gear mesh was too tight (but loose enough so it wouldn't bind). I've no experience with the MX, but based off the guide charts, my previous experience, and your description of the DEC feeling "tight" that's what I'd be looking for. I'd be making a post on the Bisque forum or otherwise contacting them for advice.
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Old 21-11-2017, 04:54 AM
E_ri_k (Erik)
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Originally Posted by codemonkey View Post
My guess is stiction; that's roughly what would happen with my old EQ6 when the gear mesh was too tight (but loose enough so it wouldn't bind). I've no experience with the MX, but based off the guide charts, my previous experience, and your description of the DEC feeling "tight" that's what I'd be looking for. I'd be making a post on the Bisque forum or otherwise contacting them for advice.
Iím going to look at the posibility of binding gears this afternoon. To me it feels like that may be the culprit. Spent a couple of hours refining my polar alignment last night. Tested them guiding, and BANG, within 5 seconds the spikes appeared again. A little disappointing, but Iíll keep going!

Erik
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Old 21-11-2017, 07:59 AM
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Quote:
Originally Posted by E_ri_k View Post
Thanks Paramount MX. Declination is balanced, and I have had all the cables through the mount for a while now. Im going to refine the alignment tonight.

I did notice one strange thing just now though..... While balancing the DEC, it feels a bit "tight" When balancing the RA, I can push it ever so lightly with my finger and it will freely move. The DEC is good up to a point, but then it feels like it sticks and will hold its position, even if unbalanced slightly. I have just given it a bit of a wiggle and seems to have freed up.....

I thought maybe the cable through the mount could be playing a part??

Erik
That is certainly uncharacteristic of an MX. However you might want to try the following. I have an MX and they can be finicky with regard to issues that cause guide error.

Balance on an SB mount must be near perfect. You need to move the mount without locks and not see any residual balance issues (ie it should stay where you put the scope and not slowly move. I think this is the most likely cause of your guiding problems.

Cables through the mount are problematic with this mount. I think I can only put one or two through my MX and after that it gets some binding. Also reasonably likely that this is causing the problem. Perhaps remove the cables and use a centre fixed loom of cables which hang to the ground from the centre of the versa plate.

Cable drag - perhaps a possibility too. Be thorough with looking at this. Cables can cause guiding errors in one part of the sky and not others.

I'd reconsider using PH2 and move to something like MaximDL or similar programme that allows both min and max movement settings. This gives better results. Probably not a likely cause to your current guide error, but it will tighten up your guiding in general.

Finally, if all that fails you need to check the worm gear for any knocks. The mount might have received a knock and damaged the worm. Or have a poke around and examine the grease and lock settings on the dec assembly.
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Old 21-11-2017, 10:58 AM
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Due various user reports, I don't recommend running cables through any Bisque mount. Cables can get stiff in cold weather or snag or both.

While it may not be pretty, an external run, tidied up with cable ties, works well, you don't have to remove the 'scope to change a cable, and you can see the location of any potential problem or snag.
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Old 21-11-2017, 11:19 AM
E_ri_k (Erik)
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Quote:
Originally Posted by Paul Haese View Post
That is certainly uncharacteristic of an MX. However you might want to try the following. I have an MX and they can be finicky with regard to issues that cause guide error.

Balance on an SB mount must be near perfect. You need to move the mount without locks and not see any residual balance issues (ie it should stay where you put the scope and not slowly move. I think this is the most likely cause of your guiding problems.

Cables through the mount are problematic with this mount. I think I can only put one or two through my MX and after that it gets some binding. Also reasonably likely that this is causing the problem. Perhaps remove the cables and use a centre fixed loom of cables which hang to the ground from the centre of the versa plate.

Cable drag - perhaps a possibility too. Be thorough with looking at this. Cables can cause guiding errors in one part of the sky and not others.

I'd reconsider using PH2 and move to something like MaximDL or similar programme that allows both min and max movement settings. This gives better results. Probably not a likely cause to your current guide error, but it will tighten up your guiding in general.

Finally, if all that fails you need to check the worm gear for any knocks. The mount might have received a knock and damaged the worm. Or have a poke around and examine the grease and lock settings on the dec assembly.
Hi Paul, thanks for the reply. I posted on the SB forum, and one comment was that binding in the DEC would produce an error, which I havenít seen.

In regards to your comment on balance, does that apply in the RA also? I have it slightly east biased. But the DEC is balanced evenly.

Funnny you mention guiding in MaximDL. I always used to guide in Maxim, until I started using SGP. I found MaximDL handled the guiding a lot better, and gave me rounder stars, not sure why though. But PHD has given me grief in the past. Tonightís test will be guiding in Maxim.

Through the mount cables is also something Iíll play with. When manually moving the DEC axis in balance mode, I can hear the cables rubbing. I only have 3 cables in there, but maybe the the cause also??

I hope the worms are all good, I donít want to go down that path! I have noticed it happening more so Iím certain parts of the sky though. There doesnít seem to be a pattern to it, and it wonít occur when I turn DEC guiding off.

Erik
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Old 21-11-2017, 01:27 PM
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Erik,

SB mounts are designed to be perfectly balanced in both axis. If you have any residual imbalance you need to eliminate this as it will cause eggy stars.
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Old 21-11-2017, 01:29 PM
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Quote:
Originally Posted by Peter Ward View Post
Due various user reports, I don't recommend running cables through any Bisque mount. Cables can get stiff in cold weather or snag or both.

While it may not be pretty, an external run, tidied up with cable ties, works well, you don't have to remove the 'scope to change a cable, and you can see the location of any potential problem or snag.
PME is ok, You could drive 10 cables through the original mount and never come close to causing binding. I don't know about the PMEII.

I thought the MEII, MX, and MX+ were a stupid design change. You definitely cannot put many cables into an MX without it starting to be a problem.
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Old 21-11-2017, 02:15 PM
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It may be the pin that locks adjusts the tension of the worm is loose. Its a bit hard to tighten it up hard.

There is a video for adjusting this pin. From memory you take off the motor cover and you'll see 2 pins and a threaded bolt. The pins need to be mostly all the way down but they seem to be able to pop up over time. Loosen it off push the pin down as far as it will go and retighten and then put the cover back on.

See if that works.

Greg.
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Old 21-11-2017, 04:08 PM
E_ri_k (Erik)
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Originally Posted by gregbradley View Post
It may be the pin that locks adjusts the tension of the worm is loose. Its a bit hard to tighten it up hard.

There is a video for adjusting this pin. From memory you take off the motor cover and you'll see 2 pins and a threaded bolt. The pins need to be mostly all the way down but they seem to be able to pop up over time. Loosen it off push the pin down as far as it will go and retighten and then put the cover back on.

See if that works.

Greg.
Thanks Greg, I recall doing this when I replaced the belts you gave me with the mount. I will adjust that also.

Erik
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Old 21-11-2017, 05:56 PM
E_ri_k (Erik)
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This was the position of the DEC cam stop. I adjusted it according to SB instructions. I removed the cover a couple of times and re did the adjustment, but the pin still likes to pop up. Not as bad as in the photo though.

Paul, I only have 2 cables running through the mount and they seem to be pretty loose/free moving. It a bit of a stuff around this late in the evening to pul them out, but if I don't have any +ve results tonight, that will be next....

Erik
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