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Hi Paul,

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By cable issues I mean cable management problems (dragging, tension, etc).? Anyway tell us if still have RA spikes after tightening the clutch.

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Regards,

Daniel

Thanks Jonathan and Daniel.

So I have a better understanding of the limits setting in Gemini. It seems that I need to take the western limit, say 100 degrees and whatever the western goto limit is set to is subtracted from that to determine when a flip will occur. ?If for example want the flip to happen right at the meridian and the western limit is 100, I would set the western goto limit to 10. 100 - 10 = 90, or at the meridian.

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In the air app, you set the number of minutes past the meridian when the air will attempt a flip by issuing another goto on the target. This has failed for me because the default western limit was 123 and the default western goto limit was 2.5, which means the flip doesn't happen because the G11 doesn't flip until 123-2.5 = 120.5 or 30.5 degrees past the meridian.

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Sound right? I will next try a western limit of 100 and a western goto limit of 9 or 1 degree past the meridian, then tell the air app to flip at 5 minutes past the meridian, which should be 1.25 degrees past the meridian, which should be far enough to trigger the G11 to flip.

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Confusing. A setting called "how far past the meridian do you want me to flip" would make a lot more sense.

First things first, if you are getting 9 out of 10 good subexposures at 2350mm, then you are good. Guiding and imaging over 2 meters focal length is always a challenge. Second, in the calibration plot there are a lot backlash clearing steps. I've confronted the same situation a weeks ago and the solution was to clean the clutch discs. The DEC one was very oil stained and that was the cause of a too much backlash clearing steps even if I cleared backlash using the calibration assistant.? But prior to checking the discs try simply with a little more tightening on both RA and DEC clutches (but not overtighten!). Last, check cables, they are the usual culprit of non periodic spikes (along with windy weather).

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Regards,

Daniel?

Hi Paul, my first suggestion would be to use the frequency analysis on that session to see if there’s any give away. Other than that I’m not of much help, I can only think of some dirt in some areas around the worm gear, or the worm, or even the gearbox and transfer gears.

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sorry, people with more experience might chime in :)

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Jonathan

I've had a heck of a time understanding where I might be getting RA - and only RA - spikes from.? My setup is a Celestron 9.25"Edge HD with an OAG, sitting on a Losmandy GM811 mount, using Gemini II, N.I.N.A and PHD2 to control everything.? Calibration looks good (See the PHD2 log) and tracking is generally very good - nearly always within 1" ...except for occasional non-periodic spikes in RA which randomly occur a few times an hour, always in the same direction.

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All gearing and bearings have been thoroughly cleaned but I suspect something in the RA train is binding up, then suddenly releasing.? I keep the clutches relatively loose.? No real differences between East and West guiding.? Alternatively, maybe it's the power supply (but then, why only RA)?? Or a corrupted signal from PHD2? One of these days I'll try swapping motors but because tracking is generally really good I don't want to fool around with the drive train until I absolutely have to.

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Regardless, I should be grateful - I typically get at least 9 good images out of every 10 - but those spikes just bug me because I can't determine root cause.? Have any of you dealt with this in the past, and if so, I'll take as many recommendations as I can get.

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Paul

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So, you ended by adjusting the back-off screw, and in this case you adjusted it a little more tight than before, am I wrong?? If that was the case you have proved that turning CCW a little that screw reduced the 76 second error but lifted the primary. This is congruent with my experience. In my case I prefered to end with a higher primary error (that can be addressed with PEC) but lower 76 second error (that can only be dealt with guiding). Nevertheless, if you are not able to get that 76 second lower than your present 4", may be you can contact Losmandy and see what they advise.? There are modifications that can be done to reduce the 76 second error, but that will void the warranty. Let see what the experts in the group can say about your mount.?

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Regards,

Daniel

On Fri, Aug 23, 2024 at 03:38 AM, Daniel wrote:

In this case PEC is not correcting the primary error (240 seconds) which is in fact doubled. I suggest to try to reprogram the mount with the PEC curve inverted. Before the PEC, as you say there is a little improvement in terms of 76 second error but not much. What did you do to adjust the SLW??

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Just followed the videos from Scott -

and - .

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On Fri, Aug 23, 2024 at 06:38 AM, Daniel wrote:

In this case PEC is not correcting the primary error (240 seconds) which is in fact doubled. I suggest to try to reprogram the mount with the PEC curve inverted.?

In this case PEC is not correcting the primary error (240 seconds) which is in fact doubled. I suggest to try to reprogram the mount with the PEC curve inverted. Before the PEC, as you say there is a little improvement in terms of 76 second error but not much. What did you do to adjust the SLW??

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Regards,

Daniel

Here are the two logs after RA worm block tweaking - slight improvement. Thoughts on the data?

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Thanks,

Ken

Thanks for the feedback. I appreciate it.

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Just watched the Losmandy video on meridian flips. I will take a good look at the related limit settings. I will also target something crossing the meridian and do an autorun and see if it works. Seems to me the ASI app and the mount need to agree on the need to flip, or the goto issued after crossing the meridian won't change anything. Last night I was well past 90 on the west side, when it should have been on the east side,

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I use USB as well.

On Thu, Aug 22, 2024 at 12:13 PM, Ed Harp wrote:

Which software makes this choice?

The ASIAIR issues commands, such as the Go-To X sequence, to which the mount responds according to the user-defined Limits. Objects only reachable on the East and West necessitate a Meridian Flip during Go-To slewing if approached from the opposite side. However, for objects in proximity to the Meridian, the necessity of a flip may vary based on the user's specified Limits.

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The movement as described suggests a limited limit overlap with the OTA initiating the slew on the West Side. Due to these limits, the target is only accessible on the East Side, yet close to the West Limit. Consequently, the mount flips to the East Side and starts tracking towards the West Limit. Shortly thereafter, it encounters this limit. Should the ASIAIR be in Autorun or Plan mode at that time, it may execute, if set, a Meridian Flip process in this vicinity, ceasing tracking and waiting for the target to drift before flipping. Otherwise, it would continue tracking to the limit, triggering the Limit alarm.

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With my air, usually start the mount, do a Cold Start, and then start the air and connect.? I use USB, by the way.??

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As far as guiding. I have never got numbers that low so can't give you much advice.? I will say it's very sensitive to calibration, and the Air will sometimes accept a wonky calibration.? ?So youbsre on the right track by re calibrating when guiding is strange.?

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For the go-to, those last few arc minutes of slew happen slowly.? You may not think the mount is moving, but it's going very slow to center up.? Just wait a few 10s of seconds.? I think you can also adjust the speed of those moves in the hand controller.??

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For homing...did you set the home position via the hand control or web interface???

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Also, mine will never confirm back to the air that it reached home.? For that reason, if I am doing more than one target in a night I will go directly between them instead of home in between.? ?

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I don't know how to directly answer your last question.? But my understanding is that the Air uses its location and time settings for the sky atlas.? Sends coordinates of the target to the mount, which then uses its location time and understanding of its current pointing to calculate the move.? So if it's going to the wrong side of the sky or pointing at the ground that usually means the time or location is wrong somewhere, or a clutch slipped or something where the mount is not physically pointing where the controller thinks it is.?

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Brian

One other issue I forgot to mention.

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Very early this morning a run of four hours was over and I had set up "autorun" to move the mount to home after. It did not move at all.

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Then I slew to another object to get a few shots and it slewed on obviously the wrong side of the pier. Even hitting the limit on that side. Which software makes this choice? The Gemini or the Air?

I have been mostly using my month old G11G with NINA, but started trying the ASIAIR this week. Overall, going well and getting good subs. But there are quirks that I would fix if there is a way.

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1. moving the mount. I find that I need to power cycle the mount with the app running before the app thinks it can move the mount. not a big deal, just have to remember the order. Starting the app with the mount already up and running hasn't worked for me so far.

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2. GOTOs generally happen, but the behavior in the ASIAIR app's sky atlas isn't reliable. Sometimes it seems to wait for moves that the mount seems to have completed. I stop the slew and tap the goto button again and it figures it out.

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3. guiding is pretty good, last night running well below 0.4" but occasionally when I first start up guiding DEC will run a bit wide back and forth. About 10 minutes or so. Recalibrating and starting over tends to clear that up. I am not manipulating any settings. I also fuss over the DEC worm. I am using machine tools to measure how much back off the worm gets and try to reliably tension the spring holding it down.

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Anyway, things like that. If anyone has any tips on using this mount with the AIR I would love to hear them. I do prefer to use NINA, PHD2 etc. most of the time but sometimes a simple setup is nice.

Thanks Paul - will have another look at the RA worm block again. Maybe things changed from the first L6 PEC work. The skies were clear here too so I may just check that again - purposely put the ASI071 on the unit to help PEMPRO also so camera should not be the weak link.

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Thanks,

Ken

I'm curious if there has been any further progress here?? It does looknlikenits way obershooting Dec, possibly due to backlash over compensation.?

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Brian

On Mon, Aug 19, 2024 at 11:08 AM, Oberon510 wrote:

I just redid my PEC training of my G11G mount with PemPro last night and got some odd results. I am not sure what to make of the results so hoping one of the Group could have a look at the attached logs and venture an opinion.

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The night sky was very clear and I had no issues with the mount (snags etc) that I know of.

Backlash in RA is not a problem, the RA motor does not need to reverse directions, so you don't need to tune the mount to lower backlash in RA.? Again, I'm no expert, but if your current guiding performance is good enough for your needs (e.g., no subs have to be discarded) I would'nt bothering in tuning the mount.?

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Regards,

Daniel