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Old 22-12-2020, 02:10 PM
Stefan Buda
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Stefan Buda is offline
 
Join Date: Jul 2013
Location: Melbourne, VIC
Posts: 837
Quote:
Originally Posted by sharpiel View Post
That's a shame for those of us who enjoy your builds.
Not to worry, there are more projects to come, but at the moment I'm still making improvements to the manufacturing methods for my CDK250. Once that is finalized I'll start another phlog. Perhaps a spectrograph or a solid Schmidt camera.

But to get back to the Zerodur, I had to generate the curve in two cuts as my cup wheel is not large enough for this job. After that I used a large bronze ring to blend in the curve. The required sagitta is almost 4mm deep and at this stage it is within 0.1 of a mm.
I also gave a bit of a grind to the back face to make the original machining marks disappear.
The weight of the blank is down to 7kg, but it took me four days of work to get this far.
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