Moonlight Focus Motor

[STEVE333]

The focusser arrived yesterday, but, had some more calibration frames to capture before moving the focus. Today, with all the calibration frames captured, I was able to remove the WO Star71 focus knob and connect the stepper motor with the supplied bracket. Drivers downloaded, and, APT said "hello" to and controlled the stepper motor. Good news.

Tomorrow I'll see how it works through the USB extension along with all the other equipment. 1 step at a time. If that works then I'll need some clear weather to test it out. With all this new equipment it's been a little overwhelming. Very excited as each new piece works.

Hopefully, more to come.

Cheers,
Steve

[Baskevo]

The focusser arrived yesterday, but, had some more calibration frames to capture before moving the focus. Today, with all the calibration frames captured, I was able to remove the WO Star71 focus knob and connect the stepper motor with the supplied bracket. Drivers downloaded, and, APT said "hello" to and controlled the stepper motor. Good news.

Tomorrow I'll see how it works through the USB extension along with all the other equipment. 1 step at a time. If that works then I'll need some clear weather to test it out. With all this new equipment it's been a little overwhelming. Very excited as each new piece works.

Hopefully, more to come.

Cheers,
Steve

Sweet! Let me know if you can get the automatic focusing function working... I still can't get good enough focus without a Bahtinov mask, which kind of defeats the whole purpose of a stepper motor for me.

Did you ever get the flat field that you wanted?

[STEVE333]

Sweet! Let me know if you can get the automatic focusing function working... I still can't get good enough focus without a Bahtinov mask, which kind of defeats the whole purpose of a stepper motor for me.

Did you ever get the flat field that you wanted?

Hi James - My objective was to be able to focus from within the house, and, looks like the focus motor will provide that capability just fine. However, I will look into the Auto Focus capability because it would be nice to be able to focus without having to go out and put the Bahtinov Mask On/Off. I'll let you know how it works.

Still working on the Flats issue. I'm in the process of adding Flat Darks to the calibration of the Flats to see if it makes any difference.

Cheers

[STEVE333]

Today I used APT to connect to all the equipment (Mount, Camera, Filter Wheel, Focusser, PHD2) and it all connected and responded over the USB extension. Whew!!!!

There certainly are a lot of cables going every which way!! I'm not happy with the Focuser motor cable hanging off the back of the telescope, but, I'm sure it will work out OK.

Next test will be trying the Auto_Focus Aid in APT to see if it can replace using the Bahtinov Mask.

More to come.

Steve

[UlteriorModem]

Good luck with the new focuser. Once you get it configured you will probably like it a lot!

Like I said put it darn near best focus point, probably manually, before you start out. Make sure that point is at like 30,000 on the index so lots of room to move back and forth.

The hardest part then is finding a good step size. There is a resource somewhere that folks have stated the step size they ended up for their rigs. Do a little googline see if you can come up with something. Being in the ball park at the start is a big time and frustration saver

[STEVE333]

Good luck with the new focuser. Once you get it configured you will probably like it a lot!

Like I said put it darn near best focus point, probably manually, before you start out. Make sure that point is at like 30,000 on the index so lots of room to move back and forth.

The hardest part then is finding a good step size. There is a resource somewhere that folks have stated the step size they ended up for their rigs. Do a little googline see if you can come up with something. Being in the ball park at the start is a big time and frustration saver

Thanks Tom - I noted the focus tube position before installing the stepper motor, so, I have a reasonable idea of where focus should be. However, I'll do the "manual focus" before getting too tricky.

Haven't been able to find anything on step size. A single step with my setup is 6 um, so, I may stick with that to start with. I'm about to check with Mike Chartrand who has the same setup. He's offered to help "get me going" with the autofocusing.

Cheers

[UlteriorModem]

Ah that's excellent. I don't remember what my step size for the Moonlight was but for the Rigel using SGP on the APO each step is 110 or there abouts. But you are fortunate to have someone's experience with the same setup.

[STEVE333]

Good news. Auto-Focus is working . I'm using APT to control the focusser and APT has an Auto-Focus Aid. I tried Auto-Focus over 15 times last night, and, each time it worked perfectly. I was able to determine the focus position for all 7 filters so that I can determine Offsets if desired.

Mike (Chartram) encouraged and supported me in getting this going as well as sharing his focusser settings. Made the whole process very easy. No more running back-and-forth between the telescope outside and the laptop display inside. No more tripping over the cables, and, no more trying to remember - did I turn the focus knob clockwise or counter-clockwise last time?

For anyone using APT I found a very useful YouTube tutorial on using the Auto-Focus Aid. The link is below.

https://www.youtube.com/watch?v=PUWkRKASVv4

Cheers,
Steve

[SonnyE]

Hi Steve,
I'm new round yer.
Beautiful images!

I'm afraid you are not quite complete as yet....
I don't see rotation in your list. You need a rotator.

Rather than wearing a path (been there, done that), I have my "Baby Dell" 2 in one tablet/laptop I use to connect to my mount/camera.
Then I use a program (free, open sourced) called Tight Vnc to connect my inside computer to my outside Baby Dell.
So much nicer than going back and forth, or shivering outside.

I think there is no end to 1. The Universe. and 2. Gear acquisition syndrome. LOL!

[UlteriorModem]

That's good to hear, I remember setting up my first autofocuser. I was clueless and practically pulled my hair out. Good news is once it is set it stays set

Now your on your way to full automation and collecting almost 12 hours of data in one night

[Baskevo]

Good news. Auto-Focus is working . I'm using APT to control the focusser and APT has an Auto-Focus Aid. I tried Auto-Focus over 15 times last night, and, each time it worked perfectly. I was able to determine the focus position for all 7 filters so that I can determine Offsets if desired.

Mike (Chartram) encouraged and supported me in getting this going as well as sharing his focusser settings. Made the whole process very easy. No more running back-and-forth between the telescope outside and the laptop display inside. No more tripping over the cables, and, no more trying to remember - did I turn the focus knob clockwise or counter-clockwise last time?

For anyone using APT I found a very useful YouTube tutorial on using the Auto-Focus Aid. The link is below.

https://www.youtube.com/watch?v=PUWkRKASVv4

Cheers,
Steve

Woot! I'm glad to hear that Steve! This is great news

Thank you for sharing that link, it was extremely helpful! I can't wait to try that out. I was thinking I was doing it wrong because my bahtinov mask was a little off every time I did it, but maybe that is not a terrible thing...
Are you going to use temp. compensation as well?

As far as the rotator goes, those things are way too expensive for the benefit! I would rather walk 20 steps and do it myself then spend $600 on an electronic focuser lol I purchased this recently: https://agenaastro.com/blue-fireball-36 ... -r-03.html

It works like a charm! I now have my imaging train fully threaded Now I don't have to worry about the field flattener slipping from the focuser, it is very nice.

[Baskevo]

So I just tried it the way he does it in the video, and although it takes a lot longer than a bahtinov mask, it seems to work well! I haven't analyzed the images yet, but I think I should be good! It is just like in the video though where the bahtinov aid says its close to focus but not quite there. But I'm glad it works!

[STEVE333]

Good news. Auto-Focus is working

For anyone using APT I found a very useful YouTube tutorial on using the Auto-Focus Aid. The link is below.

https://www.youtube.com/watch?v=PUWkRKASVv4

Cheers,
Steve

Thank you for sharing that link, it was extremely helpful! I can't wait to try that out. I was thinking I was doing it wrong because my bahtinov mask was a little off every time I did it, but maybe that is not a terrible thing...
Are you going to use temp. compensation as well?

Hi James - I'm now using the Offsets which cause a change in focusser position as you change from one filter to another. Pretty cool. I may still refocus after each filter change, but, the offset will get me closer to the correct focus which will reduce the time necessary to find the new focus.

If I get enough data to figure out how the focus changes with temperature I will definitely use the Temp Compensation. Why not, it's bound to help.

Cheers,
Steve

[Baskevo]

Very interesting--I will have to play around with these! Thanks for sharing, Steve.

[UlteriorModem]

Dont know about APT but I just set for a focus run for every 1 degree C change in temperature. No need for calculations and such.

Also offsets for filters is good for getting you in the ball park, but you should still run a focus on filter changes because their offsets will change somewhat with temperature as well.

The hardest part of getting it all set up is finding enough clear night time to do it

[STEVE333]

Dont know about APT but I just set for a focus run for every 1 degree C change in temperature. No need for calculations and such.

Also offsets for filters is good for getting you in the ball park, but you should still run a focus on filter changes because their offsets will change somewhat with temperature as well.

The hardest part of getting it all set up is finding enough clear night time to do it

Thanks Tom - APT doesn't have a true Auto-Focus routine yet. Apparently Ivo is working on that. If I want to "Auto-Focus" I need to open the Focus Aid tool and center it on a star (the current Auto-Focus only considers a single star). Next I have to open the Auto-Focus Aid and run it. That will perform the Auto-Focus. Maybe there is a way to do it with Scripts, but, that is beyond my expertise with APT at this stage. So, I'll just have to keep an eye on temp changes and perform it as just described.

Hopefully Ivo will come up with a reliable and automatic Auto-Focus in the near future.

Cheers,
Steve

[STEVE333]

Learned something new about the Moonlight Stepper Motor for focussing. The Moonlight system has a cable from the stepper motor that goes to a Controller Box that has a couple of buttons, one for moving the focus tube inward and the other for moving the focus tube outward. A USB cable goes from the Controller Box to the controlling computer.

When setting up my system I lay the Controller Box (which is placed inside a ziplock bag to protect it from the weather) on the eyepiece tray of the tripod. The other day I laid the bag on the eyepiece tray but didn't realize that the Controller box was positioned with the buttons facing down. The weight of the Controller Box pushed the button that caused the stepper motor to rack the focuser out, and, unbeknownst to me, it was continuing to rack the focuser out while I was setting up. When I went inside and connected the Focuser to APT I saw the focusser position was at about 5000 and getting bigger!! It was normally around 1150. I ran out and realized what was happening. Once turned over the Controller button was no longer pushed and the stepper motor stopped moving. Whew!!!!

The focuser had actually reached the stop and the clutch was slipping to prevent any mechanical damage. However, the ZERO POSITION (the stepper motor "position" is manually set to zero when the focus tube is all the way IN) was now corrupted. So, the next day I racked the focuser all the way IN till it stopped and then reset the stepper motor "position" to zero.

Lesson learned!! The Controller Box will always be placed "button side up" from now on. So many little things! Why can't MURPHY retire?

Cheers,
Steve

[UlteriorModem]

Huh that's a new one. Glad you didn't burn up the stepper or circuitry. I don't think they planned for continuous duty

[STEVE333]

Huh that's a new one. Glad you didn't burn up the stepper or circuitry. I don't think they planned for continuous duty

I was definitely lucky on this one. The Stepper motor "position" can go up to 10000, and, It had only gotten to about 5000, so, it was only on long enough to go about 1/2 as far as it can go. Still, ....

Cheers

[UlteriorModem]

The big issue could have been it hit the stops and the stepper kept trying to move it causing an enormous increase in current drain.

Any how I will make sure "Buttons Up!"

As I lift a toast