Celestron 8" EdgeHD & Celestron Motor Focuser?

Has anyone been able to get autofocus running with this combination? I’ve read eveything I can find about it but still not having any success. Usually the second or third focus point has a higher value than the earlier one/s, the final curve is very right-handed and a very flat curve. The final result is that the focusser is set to an HFR that is much higher than the lowest point on the curve.
At present my settings are:
Step size: 13 (Using 5x low HFR gave step size 25, using 3x gives 13)
Fine move: 10 steps (I’ve tried many settings for fine and coarse)
Coarse move: 100 steps
Data points: 9
Backlash compensation: IN 500 (is this too high? I read that it can’t really be too high)

Should the backlash setting be IN for an SCT? If moving the focusser manually to get to an initial HFR should the final move be an IN or an OUT.
I was excited to get the focusser as it was the last piece of kit I needed, but now I’m a bit deflated. I would really appreciate some help if possible.
Thanks,
Robin

Argh, frustrations with the Edge 8” and focusing - I’m not surprised. I use a Lakeside motor focuser with mine and it does work, but it is not nearly as easy or reliable as with my refractors. However, it does work, so I’m sure you can sort it out.

Here are the settings that I use, doesn’t mean they will work for you, but it might give you some ideas:

Backlash: IN 800
Focus: Bin 2x2, 9 points, step size 75, min diam 3. Exposure times are 10 seconds with Lum filter, 15 seconds with RGB filters and for the narrowband filters I use Lum and offset values.

So I would suggest you try increasing your backlash value to start with. Also, don’t forget that you need to be pretty well in focus before running auto focus for the first time in the sequence.

Good luck, I hope you make some progress.

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PhotoGav (Gavin?) thanks for those suggestions, I’ll give them a try tonight if it stays clear. It was supposed to be clear last night but it was ruined by high level thin cloud.
Robin

If the v curve is wonky, it is often an indication that the collimation is incorrect if my RCT is anything to go by.

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Progress!! For the first time it worked with and I got two green lines with a Ha filter. Didn’t quite work with the SII so some more adjustment needed.

Excellent! Don’t forget the offset route for narrowband filters, using the Luminance filter to actually focus - much quicker and more reliable than focusing with the narrowband filters themselves.

I’ve only had my Celestron focuser with my EDGE HD 8 since May, but our skies most of the summer have been really lousy. I use a step size of 50 but haven’t figured out how to calculate the backlash setting. For the limited use I’ve had with it, the V-curves have always been very good.

Photogav is correct. You need to get close to focus so you can add these values into your Filter window. For my ZWO ASI1600MM -Cooled, I use 6 sec for LRGB and 20 sec for my NB filters; both binned at 2x2.

I still learning but have been pleased with the results so far. I’m sure there’s still more to learn with this focuser.

Hope you continue to make progress and report your results! David