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Refiguring a Dynamax 8" Schmidt Corrector

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#851 deSitter

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Posted 14 March 2018 - 01:36 PM

I've seen a TEC show similar lines when it was still warming up (garage to indoors). Not saying that's the case here but it's interesting that the DPAC images are strikingly similar to a cooling/warming scope.

Interesting point

 

-drl



#852 tim53

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Posted 14 March 2018 - 02:25 PM

I've seen a TEC show similar lines when it was still warming up (garage to indoors). Not saying that's the case here but it's interesting that the DPAC images are strikingly similar to a cooling/warming scope.

Good point.  I will have to check that at some point, because I can't remember how long it had been indoors when I did the test.  In any case, I'll have to test it again to determine where the problem is.  So I'll find out before I can do any damage.

 

 

-Tim.



#853 tim53

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Posted 14 March 2018 - 02:26 PM

There was an Intes design that looked superficially like a Gregorian Mak but was said to be actually a Rumak. The secondary spot had its own spherical curvature and all optics were spherical. I think this scope is f/10 (correct?) so it may be one of those. 

Yes.  f/10



#854 SteveGR

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Posted 14 March 2018 - 09:55 PM

Good point.  I will have to check that at some point, because I can't remember how long it had been indoors when I did the test.  In any case, I'll have to test it again to determine where the problem is.  So I'll find out before I can do any damage.

 

 

-Tim.

Hopefully that's all it is, it's such a nice looking instrument.



#855 Gil V

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Posted 15 March 2018 - 02:04 PM

All you need to do is follow the directions here....  wink.gif

And spend two years on the project.



#856 DAVIDG

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Posted 15 March 2018 - 02:31 PM

And spend two years on the project.

 It is  a hobby not my job and that is one reason why it has taken this long.

    I showed that I refigured two surfaces from many waves from optically flat  to around 1/10 wave in  two evening because I understood the process. In the case of refiguring the corrector  like I said many times it is  an experiment to find the correct procedure without making a  major mistake. 

   Feel free to show us how it is done if you feel you can do it faster. 

 

                      - Dave 


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#857 tim53

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Posted 15 March 2018 - 02:35 PM

From Albert Ingalls' Preface to ATM:  "Some of the workers -- a very few -- have strongly urged that the amateur's telescopes be standardized on a few definite type specifications, arguing that this would save labor. Others believe that standardized hobbies connote standardized people with standardized ideas, and that the introduction of mass production and labor-saving ideas of efficiency in connection with a hobby is comparable to hiring a workman to play one's games for him. A hobby should be a way to waste time, not to count it."


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#858 Gil V

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Posted 15 March 2018 - 05:42 PM

It is a hobby not my job and that is one reason why it has taken this long.
I showed that I refigured two surfaces from many waves from optically flat to around 1/10 wave in two evening because I understood the process. In the case of refiguring the corrector like I said many times it is an experiment to find the correct procedure without making a major mistake.
Feel free to show us how it is done if you feel you can do it faster.

- Dave


Apologies if I crossed a line. Please take my comment in the good humor it was intended.

I do appreciate all your work, you are teaching more than I have capability to learn.

About a year after the plant closed, I ran into the last guy who ever built RV-6 mounts. He was not a smart man by measure of any fair-minded man, but he had a good heart. He said it best:

“Oh well. We tried.”
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#859 DAVIDG

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Posted 15 March 2018 - 08:00 PM

Gil,

  Apology accepted. All I keep trying to do is help people enjoy this hobby better and part of that process is to try to separate the fact from the fiction.  Stay tune and I  hope to get back on the corrector soon and hopefully I'll work out a way to fix one if someone  wants to give it a try.

 

                  - Dave 


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#860 Bomber Bob

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Posted 15 March 2018 - 08:09 PM

A hobby should be a way to waste time, not to count it.

 

Amen!  I spent about a year -- off & on -- on the Mogey before I called it done.  I've had the Tinsley for years, and it's still a work in progress.  Putting in the sweat equity has given me a real appreciation for what Dave has done with this Dynamax 8.  I draw the line at re-figuring optics, but I'm glad that he's crossed it to present & share this tutorial.


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#861 Geo31

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Posted 16 March 2018 - 06:42 AM

And spend two years on the project.

 

Hehe...  Yeah, I know.  Not this project.  I was looking at my Celesterion RVC-6N thread the other day.  I've barely touched it in two years.  It's probably 75-80% done, but other priorities in life have crowded it out.  I think it will be done late summer though.

 

Steady progress is a good thing.  And quite frankly, for me (on this thread), it gives me time to process what Dave is teaching/showing.  None of this has been overwhelming, which would be easy to do.  I'm certainly content to follow along at home.  :grin:  This is one of the best threads on here.


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