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Adjusting the secondary in an Explore Scientific 12" dob

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#1 kurtfriedrich

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Posted 22 October 2021 - 07:05 PM

Most Newtonians have 3 screws to adjust the secondary angle and if you move all 3, you can raise and lower the secondary in the primary path.

However the Explore Scientific dobs have the 3 screws perpendicular to the primary path, and while you can adjust the angle, you cannot move the mirror up and down.

The focuser is mounted into 4 holes which are slots, so you can loosen the screws and get some adjustment, but I need more.  Has anyone solved this problem?gallery_16287_17924_7921.jpg



#2 kurtfriedrich

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Posted 22 October 2021 - 07:10 PM

I might try adding washers and longer bolts to the truss attachment points to raise the secondary, see the green arrows.

Does that seem like a bad idea?

 

gallery_16287_17924_21788.jpg



#3 Couder

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Posted 22 October 2021 - 07:17 PM

Don't the vanes adjust?



#4 kurtfriedrich

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Posted 22 October 2021 - 07:19 PM

Don't the vanes adjust?

Only left and right to get it centered, not up and down.

thanks



#5 Jon Isaacs

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Posted 22 October 2021 - 09:32 PM

I might try adding washers and longer bolts to the truss attachment points to raise the secondary, see the green arrows.

Does that seem like a bad idea?

 

gallery_16287_17924_21788.jpg

 

That raises both the focuser and the secondary, that wouldn't help if you are trying to position the secondary relative to the focuser for collimation purposes.

 

Jon



#6 kurtfriedrich

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Posted 22 October 2021 - 09:51 PM

That raises both the focuser and the secondary, that wouldn't help if you are trying to position the secondary relative to the focuser for collimation purposes.

 

Jon

Dah!!

 

Guess I'll have to put in double then!!!!

 

thanks




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