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INDI Library v1.9.9 Released (30 Nov 2022)

Bi-monthly INDI Library released with new drivers and bug fixes.

INDI focuser driver for Waveshare Stepper Motor HAT for Raspberry Pi / Rock Pi

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And a problem like this wouldn't be complete without a facepalm. I just noticed with the stepper attached to my RedCat, if I ran it from 0 (fully retracted) to nearly max (500) and then back to 0, it kept missing the zero point by a few degrees (it was always short). It turns out the grub/set screw for the pulley attached to the stepper is loose. Double-d'oh! That means I have at least 10+ steps of backlash. I'm guessing it will work much better with a tight pulley.
2 years 6 months ago #54518

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Well, all problems in astrophotography are mechanical or optical in the end....

:)
Atlas Pro AZ-EQ, ASI1600MM-Pro, ASI120MM-S, ES102ED, WO-Z61, Nikon D3300, ASI-EFW, ZWO LRGB,Ha,O3,S2 filter set
Last edit: 2 years 6 months ago by Jose Corazon.
2 years 6 months ago #54520

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Consider yourself getting off easy! When I did the Rowan belt mod for my Orion Atlas mount, one of the set screws on a pully deep inside the mount wasn't tight enough. Took me a month to figure out why I was getting such bad backlash in Dec movements! So I had to tear the mount apart to tighten that screw. I put blue Loc-Tite on those screws, just because I was mad at them!
2 years 6 months ago #54521

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With my existing stepper, backlash now seems to be around 1 step. I can see clear consistent movement for even a single step and when changing directions at most that first step doesn't show full movement. I can see that with large moves in one direction followed by single step moves in the other. When does darkness get here? I really can't way to try it out again.
2 years 6 months ago #54522

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Its especially ironic because the grub screw is one of the first things I advise others to check for many different kinds of 3d printer issues. I need to take my own advice.
2 years 6 months ago #54523

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I still want to go head-to-head with your design.

Identical optical train, so it's just the focuser.

We got to have a competition, Eric!!!

:-)

Best, Jo
Atlas Pro AZ-EQ, ASI1600MM-Pro, ASI120MM-S, ES102ED, WO-Z61, Nikon D3300, ASI-EFW, ZWO LRGB,Ha,O3,S2 filter set
2 years 6 months ago #54524

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I win, been there done that :) I hate Helical's
Last edit: 2 years 6 months ago by Clive Garner.
2 years 6 months ago #54525
Attachments:

    redcat.avi

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That is cool! The key is the tension pulley. That makes all the difference for eliminating backlash, I bet.
Alright, you can be part of the Olympiad here.
I am not chickening out. I am still confident I will win.
:-)
Jo
Atlas Pro AZ-EQ, ASI1600MM-Pro, ASI120MM-S, ES102ED, WO-Z61, Nikon D3300, ASI-EFW, ZWO LRGB,Ha,O3,S2 filter set
2 years 6 months ago #54526

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Already tested, and it worked a treat, the last pic is of Rho, having used full autofocusing
Last edit: 2 years 6 months ago by Clive Garner.
2 years 6 months ago #54527
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Very nice! Just curious, what are using to control the stepper motor? The Waveshare HAT, or some other (possibly Arduino) controller?
2 years 6 months ago #54528

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Yes, very nice! I think as far as accurate focus is concerned, this may come to a draw. This is what I got from the middle of a large metro area (Dallas), Bortle 8/9, and with an inferior mount (iOptron SmartEQPro+; RMS 4+, 7 arcsec/pixel).



Not nearly as nice as yours, editing not yet completed, needs more narrowband, but this is about focusing. The focusing routine (linear, automated and repeated hourly through the night) was posted earlier in this thread.
Atlas Pro AZ-EQ, ASI1600MM-Pro, ASI120MM-S, ES102ED, WO-Z61, Nikon D3300, ASI-EFW, ZWO LRGB,Ha,O3,S2 filter set
Last edit: 2 years 6 months ago by Jose Corazon.
2 years 6 months ago #54532
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The focused worked much better last night. I now get the expected V / curve during auto focus. I could repeatably move focus away from the focus point and back to the same step number and things were in sharp focus. I still need to tune the parameters for the auto focus algorithm itself. It was never able get it to automatically choose the focus point (though I was able to choose it myself based on the data from the auto focus process). I’m using the linear focus algorithm. Once it finishes the first pass, it then appears to try to take multiple readings at the same steps right around the focus point. However my seeing must be varying enough that it couldn’t get consistent enough readings without moving the focuser and would eventually error out. I adjusted the tolerance % without success, though I’m not sure that’s the right parameter. I didn’t spend a lot of time as I wanted to get started imaging, so I just chose the best focus point and moved on.
2 years 6 months ago #54558

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