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Complete Collimation of the Meade Schmidt Newtonia

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#1 asaint

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Posted 09 May 2008 - 06:31 AM

Complete Collimation

#2 mattyfatz

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Posted 09 May 2008 - 10:21 AM

WOW...
This is a very informative article. Thank you

#3 Scott Beith

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Posted 09 May 2008 - 10:27 AM

Outstanding article. Very detailed with supporting pics. :bow:

#4 Ed Sunder

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Posted 09 May 2008 - 04:03 PM

Fantastic article - is there any way to see larger images?

#5 Starman1

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Posted 09 May 2008 - 09:24 PM

A needed article, if posts on CN are any indication.
Thanks.
You can make the pictures larger easily by right clicking, saving the pix on your desktop, then opening them and expanding.

#6 gjuncker

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Posted 13 May 2008 - 05:35 PM

Awesome article! Makes me wish I hadn't sold my 6" Schmidt-Newt! I could never get it collimated and after what seemed like ten thousand hours of trying, I got rid of it.


>The only major problem I had with my Meade Schmidt-Newt that wasn't addressed was the outrageous amount of focuser slop and its slightly oversized bore. No laser collimator I ever put in it pointed at the same spot twice. And racking the focuser in and out even slightly would move the laser spot on the primary by half an inch or more. Maybe I am glad I sold it after all.<

--G√ľnther
Toccoa, GA

#7 johnmkanz

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Posted 15 May 2008 - 08:17 AM

One of the best how-to's I have seen here to date.
Regarding secondary rotation, I suppose that method of checking with the T-paper shape would also work with any newt/mak-newt as well, no?
johnk.

#8 Ed Sunder

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Posted 19 May 2008 - 09:15 PM

All right, I've gone through all the steps now except I don't have a cheshire. The secondary mirror seems to look like it's supposed to, but when I shoot my laser collimater down it's almost an inch off of center on the primary mirror. If I spin the collimater, the laser stays right on that spot and I've made sure that the collimator itself is collimated. Should I adjust the secondary to put the laser on the center? I'm fairly sure I can't adjust the primary enough to move that spot to the center. should I just use the collimater as-is, even though it doesn't seem to be pointed to the right spot? Or should I just go ahead and get a chishire tube? Any suggestions would be appreciated.

#9 ClownFish

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Posted 20 May 2008 - 12:13 AM

With the primary removed, add two strings through the primary attachment screw holes to make an "X" at the bottom of the tube. Then adjust the secondary to center that X in the focuser. This will ensure the secondary is indeed pointing straight down the optical tube. A collimation cap or cheshire is a must.

Once that is done, if you are still not showing a centered laser, check that the center spot on the primary is center, and also that you are 100% sure the primary is centered within the primary holder,

CF

#10 Ed Sunder

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Posted 20 May 2008 - 08:54 AM

ClownFish,

That's a great idea. I wish I'd have thought of it. Thanks.

#11 ClownFish

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Posted 23 May 2008 - 12:17 AM

No problem, always glad to help out and share any techniques I know of. And just so that everyone knows, this idea of tying strings at the bottom to form a cross-hair was not my own; several articles on the net discuss it, and the co-author of the article, Danny Lunsford, also suggests using it.

You can find additional details of this "string" technique, here..

I'm glad everyone is enjoying this helpful tutorial that Danny Lunsford (DeSitter) and I wrote. It contains a lot if techniques compiled from many sources, so no one person should get full credit. The idea for the "Blue Ghost" was Danny's own, so all comments about that should be direted to him. The "Paper T" technique was best described by Danny, and I have little experience using it so please send comments aboit that procedure to him as well. The "Rod Rotation" technique was mine, and I would like to hear if anyone else has found that it works. Some have found that it does not work with their specific Meade SN. I would appreciate hearing from more users, so see if this technqiue is truley worthwhile.

CF

#12 Kinsale

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Posted 23 May 2008 - 12:29 PM

This is a excellent article. I've struggled to collimate my SN-10, and even though I've gotten it close I still think the collimation could be a bit better. I'm hoping this will help.
When I try to print out a hardcopy of this article the first 7 pages seem OK, but for the rest of the pages the edges of the photos get clipped off. I've tried saving it in different formats, including Word, to try to fix this problem, but with no luck.
How about re-posting the article as a pdf?


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