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3D printing a Bahtinov mask for my UC18

 

My 3D print version of a Bahtinov mask underway for my UC18. ?This will replace my wooden version that i cut out with my jig saw.
?
Richard
 

Richard
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Where did you find the mask? I've got an 18" classic and would love to find a mask, as I want to do photography through it and am working with manual focus.
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Thanks!
Mark
 

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Mark,

I created a Bahtinov mask in CAD with a hole to fit over the secondary and 3 notches to rest on the Obsession style secondary support. ?I have one more section to print to complete this version #2.

My first version was made out of 1/8¡± plywood. ?This second version is printed on my new 3D printer in quarters and glued together.

These make really nice ¡°crows feet¡± patterns. ?Adjust your focus for a centered middle toe of the crows foot for perfect focus on a bright star.

Our Obsession telescopes outfitted with ServoCAT and Argo Navis tracking will deliver great astrophotography once you achieve focus. ?

Do you have a 3D printer??

Richard

From: [email protected] <[email protected]> on behalf of Mark Gregory <hackaroo@...>
Sent: Saturday, November 2, 2024 7:12 PM
To: [email protected] <[email protected]>
Subject: Re: [ObsessionUsers] 3D printing a Bahtinov mask for my UC18
?
Richard
?
Where did you find the mask? I've got an 18" classic and would love to find a mask, as I want to do photography through it and am working with manual focus.
?
Thanks!
Mark

processed-E3842EE3-18C5-491B-A86A-E966E527C559.jpeg

 

Mark,
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Here is the view of the center toe of the crows feet to achieve good focus with my wooden version of the mask.
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?
Richard
 

Mark (and others),
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Here is a link to an on-line tool with which one can create an .svg or .dxf file of a custom-sized Bahtinov mask:
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On that webpage there are links for two other mask designs, in addition to the classic one:? a "tri-bahtinov mask" and a "second modified tri-bahtinov mask".
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Mark T.
 

Richard:
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Yeah, I know what a nice tool they are - I've got a 3rd party mask for my 8" Celestron Edge HD. I do not have a 3D Printer, but my son does. I used one of the online mask generators, but my son couldn't figure out how to quarter it to print, and he's far enough away that I don't get down to see him and play with it myself. I've got a nice Mallincam and am using SharpCap, so have the tools on that end of things. Now if I could only get a clear sky some night.
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Mark
 

Just information here guys. I have a 22" UC, and I have an 11" Celestron RASA, I have a Bahtinov mask that I purchased specifically for use on the 11" RASA,
it has a hole in the middle of it similar in size to the RASA central obstruction.?

When I need to confirm focus on my 22" UC, I simply balance the 11" mask on the secondary cage of the 22" UC and it seems to work just as if it were a full aperture mask for focusing.
It can hang there kind of sideways, or crooked, and it does not seem to make a difference.

I am considering cutting 3 notches in the central hole of the mask just to make it center up better with the three bars that support the secondary on the 22".

My conclusions after trying this are:?
(1) the Bahtinov mask does not necessarily have to be perfectly centered to do its job well
(2) the mask does not necessarily have to cover the full aperture to do its job well
(3) when using it, most of the time I find out that it just "Confirms" that I have already achieved the best focus by eye!, and I have wasted my time dragging out the mask, but I "feel" much better.

So for what it is worth, there you go, hope this info helps somebody.

  • Corey Sloan
  • Senior Illustrator / Design Consultant
  • Mohave County Pools & Spas
  • mcpcorey@...
 

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Mark,?

I just made a ¡°body¡± for each section and then just exported each section as a stand alone ¡°stl¡± file and then sliced into gcode. ??

Good luck. ?

Richard

From: [email protected] <[email protected]> on behalf of Mark Gregory <hackaroo@...>
Sent: Sunday, November 3, 2024 1:06:06 PM
To: [email protected] <[email protected]>
Subject: Re: [ObsessionUsers] 3D printing a Bahtinov mask for my UC18
?
Richard:
?
Yeah, I know what a nice tool they are - I've got a 3rd party mask for my 8" Celestron Edge HD. I do not have a 3D Printer, but my son does. I used one of the online mask generators, but my son couldn't figure out how to quarter it to print, and he's far enough away that I don't get down to see him and play with it myself. I've got a nice Mallincam and am using SharpCap, so have the tools on that end of things. Now if I could only get a clear sky some night.
?
Mark

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