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Ekos calibration is a mess.


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Bit of progress this evening...! For some reason binning 1x1 works much better 2x2 and always has so I stuck with that. Decreasing calibration pulse duration seemed to make things worse so, to

Hi @Danield06 Thanks for the reply. The plot is not even nearly orthogonal but I suspected it should be. I had been trying to find images or videos of other people's calibrations but struggled 

Thank you for all that info. I really appreciate it. The EQ5 kit doesn't seem to be particularly well known but it's a belt-driven stepper motor kit. I think my mount RA gearing could be tightene

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I'll give that a go.

Unfortunately I wasted most of the night thinking something was too tight or binding only to find out that ekos go-to speed is, apparently, not adjustable, and wants to go way faster than my motors can handle.
Slewing anywhere at any (supported) speed is tip top, but go-to is a waste of time as it tries to go at 1000X, or whatever, and the motors just can't do it.

I'll be back.

Edited by Steenamaroo
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35 minutes ago, Steenamaroo said:

ekos go-to speed is, apparently, not adjustable

You set the goto slew speeds in the indi control panel. I don't think you'll get 1000x so choose something more reasonable such as, say, 600x. Still quite fast. 

HTH

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Ugh. Packing up for the night.
Can't believe I've fanally made some progress with guiding (not quite enough to guide) only to find that goto isn't an option.
This is really starting to turn into a chore rather than a hobby. :(

With the motors removed I can turn the large pulleys with my little finger, and the motor skipping issue even happens with clutches disengaged so it seems clear the motors are just weak.
I sent an email to the manufacturer asking about the weak/high speed goto but unless he points me to a magic 'increase torque' button, I can't see much coming from that.

Edited by Steenamaroo
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11 hours ago, Steenamaroo said:

goto always tries to operate much faster

ss4.jpg.9e974f74948bcb82282ef7c2cb4071d7.jpg

Hi

There are 4 speed presets; Guide, Centring, Find, Max. For Max, choose whichever you feel the motors will handle. On my eq6, the max is 800 but it sounds far happier at 700.

Maybe it would be easier to access them via the Mount Control popup slider instead? There are always loadsa different ways to attack a problem with indi!

Cheers

ss5.jpg.99f6e439aae374ec9303ecbbf102039b.jpg

 

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9 hours ago, Steenamaroo said:

chore rather than a hobby.

Yeah, it can seem like that. Take a step back?

The turning point for me was watching someone who knew what they were doing. Live. One to one. Then realising that none of what he was doing was particularly difficult. ATM that maybe restricted to a video call, but it's a sure way to get bump started. Diagnosis via forum is so much more difficult.

Cheers and good luck.

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You're quite right, particularly when it comes to things like tightening/loosing. How tight? How loose? That's much easier to gauge when you can feel it or, at least, see someone else do it.
I appreciate your advice and patience.

My indi motion tab is slightly different to yours (pictured) but please be assured, as much as this guiding saga is doing its best to make me look like an idiot, I'm familiar with the speed controls.
I had previously been setting 'custom' to 300 or so as a nice balance for use when polar aligning and that worked as you'd expect.
The max speed, set explicitly or via 'custom' is 800X, and slewing at 800X or less is perfectly fine.

The issue is that when using 'goto' on a target the mount takes off not just at the highest list speed, but higher!
Investigating it for a while I think I'm right in saying the stepper motors struggle and skip the most when both axis are rotating together which, I notice, I cannot even do manually at the highest user-speeds (6/7/800) using the pictured motion control panel or synscan app. Pressing and holding the NE/NW/SE/SW just results in travel on one axis - N, or S.
Speaking of synscan app, I tested goto from there, while I had it open, and noticed that it also runs goto at these same higher speeds so that's making me think it's a firmware level thing?

The seller/manufacturer suggests loosing the worms slightly to make things easier on the motors but I took a bit of time last night to make sure it was a loose as could be without introducing noticeable backlash.

I think, perhaps, a video of me operating the worm shaft by hand, with motors removed, might be a good idea.


Sorry folks, I know this deviates from the original post and issue - Hope that's OK.

Screenshot 2020-11-05 at 12.42.14.jpg

Screenshot 2020-11-05 at 12.26.17.jpg

Edited by Steenamaroo
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Not sure if I'm on to something or not but I notice that goto moves in both axis at the same time.
If I attempt to move in both axis at the same time using the pictured motion control panel, or the seller-recommend synscan phone app, it does not work at 6/7/800X.

Attempts to move N/E, for example, just move N.
Attempting S/E just goes S.

It seems like the E/W movement is attempted, at first, but just stops after a second, while the N/S movement continues.

I've passed this onto the seller/manufacturer too, incase it's relevant.

Edited by Steenamaroo
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Update : Seems goto speed is, indeed, set at firmware level.

Seller sent me a service version of the kit settings app which allows the setting of max goto-speed.
Default was 1000X. I reduced that and restarted and the issue seems to be resolved. :)

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Bit of progress this evening...!

For some reason binning 1x1 works much better 2x2 and always has so I stuck with that.
Decreasing calibration pulse duration seemed to make things worse so, to experiment, I increased it.
That seemed to really help the shape of the guiding plot, so I kept increasing/testing/increasing testing.

Under advice from @Danield06 I went with 2.5 exposure, multistar algorithm, and auto-star.
Seems like a solid combination.

Once it was running well I thought I'd subtly tweak some values to see if I could improve it further and found that increasing proportional gain to 166 did just that.

 

In the end I had under 0.5 total RMS for about 5 minutes so I'm very happy with that.

 

Many thanks to everyone who has offered advice, or encouragement!

Screenshot 2020-11-06 at 21.27.55.jpg

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10 hours ago, Steenamaroo said:

binning 1x1 works

Yeah. 2x2 at that focal length is gonna give you football-pitchº per pixel!

Good to see you've switched to SEP-multistar. Nothing else comes close.

15 is the recommended guiding calibration distance. You may want to adjust the pulse length and the number of pulses.

To improve even more, try using the GPG algorithm for RA. It will smooth any PE in the mount after a few minutes' guiding.

Well done for sticking at it.

Edited by alacant
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2 hours ago, alacant said:

15 is the recommended guiding calibration distance. You may want to adjust the pulse length and the number of pulses.

To improve even more, try using the GPG algorithm for RA. It will smooth any PE in the mount after a few minutes' guiding.

Well done for sticking at it.

Thanks @alacant
Certainly up for further improvement, although I'm very happy now, but I don't see either of those options.
Are they PHD2 settings, rather than KStars/Ekos?

I did take your initial suggestions about more calibration iterations and shorter pulses but things seemed to get worse.
As I say there, out of curiosity, I went the other way with longer pulses to see what would happen and things started looking much better.

I'm not sure if number of iterations made a big difference but certainly longer pulses was a key to getting a decent-ish looking plot and much better guiding,
so thank you, either way, for pointing me in that direction.

Edited by Steenamaroo
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Just a quick question. What is your gain and offset for your guide camera? I am not seeing many stars in your image. I use a 120mm mini and guide with an OAG and I get significantly more stars. I am guiding at about a 400mm focal length and near the edge of the field as well.

Edited by Danield06
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On 06/11/2020 at 18:19, Steenamaroo said:

Bit of progress this evening...!

For some reason binning 1x1 works much better 2x2 and always has so I stuck with that.
Decreasing calibration pulse duration seemed to make things worse so, to experiment, I increased it.
That seemed to really help the shape of the guiding plot, so I kept increasing/testing/increasing testing.

Under advice from @Danield06 I went with 2.5 exposure, multistar algorithm, and auto-star.
Seems like a solid combination.

Once it was running well I thought I'd subtly tweak some values to see if I could improve it further and found that increasing proportional gain to 166 did just that.

 

In the end I had under 0.5 total RMS for about 5 minutes so I'm very happy with that.

 

Many thanks to everyone who has offered advice, or encouragement!

Screenshot 2020-11-06 at 21.27.55.jpg

Looking good! You seem to be getting there. Has this been consistent? IS your guiding working better? That calibration plot looks much better

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I've only had one opportunity to test and that was it, but I was able to calibrate and produce similar results three or four times in a row.

This week has been wall to wall cloud, unfortunately, but next chance I get will be confirmation night (I'll report back) and then after that maybe I'll take a photo of something. 😀

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  • 2 weeks later...

Hey all.

I finally got another opportunity to get a proper test done and everything went really well.
Here's the calibration plot.

1733964214_Screenshot2020-11-22at22_25_02.jpg.33054dd77a12797fa43c43b244663df4.jpg

 

All this 'practice' meant that set up only took about 15-20 minutes, so that's great.
I figured I'd take some shots of M42 and see what I could get. Didn't invest a huge amount of time as it was a first trial but I'm damn pleased with what I got!

2138221088_Screenshot2020-11-23at23_33_41.jpg.964eea68d116513bea2e3fb7e1889db0.jpg

 

Thanks once again to everyone who offered advice and help here. :)

(and yes...take flats next time)

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