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Rigged up a power focus to reduce vibrations

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#1 roykirk

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Posted 14 June 2019 - 06:08 PM

I'm certainly not the first to do this, but I thought I'd share my little project:

 

https://drive.google...XBWlnL3yeuYo7LO

 

This is a remote powered focus motor that I rigged up for my Celestron 6 SE.  I thought the prices out there for a model specific powered focus motor were ridiculous (about $200).  I bought this motor on Amazon for $80.  I think it was originally designed for an Orion telescope, but as you can see in my photos and video, I adapted it to the Celestron pretty easily.  Works great and I'm excited to get some viewing tonight without the constant vibration issues I get when trying to focus by hand. 


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#2 deansjc

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Posted 14 June 2019 - 06:50 PM

Interesting project.  Can you provide some motor specs and dimensions, or the Amazon item number and any relevant info on the controller/switching mechanism. and method of attachment.

 

I'd love to hear your feedback after using. Of most interest to me is whether you have fine enough control for tight focus.  My only trick thus far is an ultra-light 7 inch "wand" that attaches to the focus knob, allowing for the slightest of rotation.  I put up with the resulting vibration that settles quickly enough for me, at least for now :-)

 

Thanks!



#3 roykirk

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Posted 14 June 2019 - 07:15 PM

You bet.  Here's the motor I ordered:

 

https://www.amazon.c...duct/B00077261C

 

It has a motor speed control, in addition to the direction control.  It's still daylight here, but in testing it out on some terrestrial objects around the neighborhood it seems to work quite well.  The only problem I notice is the rubber gasket I used in the photos/video has a tendency to want to "wander" off the motor spindle after a few minutes of use.  I may try to find a way to rig up a gear to the spindle so it has a way to grip better.  



#4 skaiser

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Posted 14 June 2019 - 08:00 PM

You can also find interesting ideas along this line in the "articles & reviews "  section of this forum.

I did a similar idea with the focus control via bluetooth.

if interested, do a search in the "articles & reviews " section for  DIY bluetooth.

You might be able to use my "belt" drive idea for your setup.

Nice work!

take care


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#5 roykirk

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Posted 15 June 2019 - 08:42 AM

It worked great.  Was finally able to get decent focus without everything in my viewfinder looking like a blender. 



#6 Arctic_Eddie

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Posted 15 June 2019 - 12:22 PM

Here's a stepper motor version I developed in 2012. The complete ZIP file is no longer on the RR home page as that has been eliminated by the provider. The video is still on YouTube with a link further down the post.

 

https://www.cloudyni...s/#entry4826773

 

Article with all data.

 

https://www.cloudyni...r-focuser-r2706


Edited by Arctic_Eddie, 15 June 2019 - 12:23 PM.


#7 roykirk

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Posted 15 June 2019 - 06:19 PM

Here's a stepper motor version I developed in 2012. The complete ZIP file is no longer on the RR home page as that has been eliminated by the provider. The video is still on YouTube with a link further down the post.

 

https://www.cloudyni...s/#entry4826773

 

Article with all data.

 

https://www.cloudyni...r-focuser-r2706

That's impressive!  I actually thought about going with the servo and belt route as I have 3D printers and many parts from those laying around.  But I knew coming up with a servo controller was going to be time consuming (at least for me).  Just going with something off Amazon that I could hook up with a rubber band was the lazy man's way out.  grin.gif


Edited by roykirk, 15 June 2019 - 10:28 PM.


#8 Arctic_Eddie

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Posted 16 June 2019 - 06:27 AM

I had also considered a servo but it needs a position feedback mechanism to work correctly. Since there's no heavy load on a stepper it will work fine. Having direct response to your hand makes a big difference in how it works. My device is rather complex for what it does but the results on the 6SE and the AT80 is quite pleasing.


Edited by Arctic_Eddie, 16 June 2019 - 06:32 AM.



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