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Strokes for adding correction in a 14" mirror

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#1 Jens.Jacobsen

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Posted 27 January 2020 - 01:18 PM

Hello.

 

I am currently working on a 14" f/4.3 mirror. I have done the first part of the correction with a full-size lap, and as it is now, the mirror is nice and smooth. But not enough correction and especially the edge is lagging..

 

ml-toc14.JPG

 

My plan is to use a 50% lap, and work TOT, using tangential strokes. But I am unsure about what length of strokes and how far offset from the center...

 

I don't have a whole lot of experience with sub-diameter laps....

 

Suggestions?

 

/Jens



#2 Pinbout

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Posted 28 January 2020 - 06:41 PM

Full size tool on top centered n the .7 zone tangential stroke will add correction to the outer zones



#3 Jens.Jacobsen

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Posted 31 January 2020 - 10:59 AM

Hi Danny.

 

Thanks for your reply.

I would never have tought that a full-size lap would work on the outer zones...

 

I did a run with polsim, and it looks somewhat like this...

 

fullsize-offset.JPG

 

Is that what you suggest??



#4 Pinbout

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Posted 31 January 2020 - 09:57 PM

rotate the entire picture 90deg right, yes... 

 

i like to make pictures like how Id use the setup, so I always work the right side of the mirror, stroking to and away from me...

 

as you can see the outer zones are flattening and thats what you want...

 

don't do strokes that are too long.



#5 Jens.Jacobsen

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Posted 01 February 2020 - 02:59 AM

wink.gif  My preferred side is to the left, but no matter. Yes, i am very conscious about the edge, which is fine for now.The mirror has a nice bright ring. So I do want to avoid a turned edge. I did a 10 minute session with the full size lap yesterday evening. The mirror has spent the night in the test stand, and after a cup of coffee, I will check how much correction it added.

If it is not to windy!

My workshop (wooden structure) has a tendency to sway slighty in the wind...


Edited by Jens.Jacobsen, 01 February 2020 - 03:00 AM.



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