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8" Mirror Grinding
8" F6 Project

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After many hours of figuring an testing I finally achieved my goal of 1/10 wave. The final result actually averaged about 1/12 wave. Once the focult tests showed these kinda of numbers I wanted to do some kind of star test to see if the mirror was going to show decent image or not, before I sent it to a mirror coater.

I spent about a month constructing a test fixture. This aided in validating the primary an secondary mirror placement along with testing the actual performance of the telescope with real stars. Also this helped me make decisions on some of the design components that I would use for the finished scope.

Looking down the tube one can see the uncoated mirror, along with the frost buildup from the cold February night. I was surprised how the uncoated mirror was able to show crisp star images an resolve some planetary detail in Jupiter. The hard work pays off and I was thrilled when I seen the 1st objects in it. With no finder attached I used some easy targets like Vega, Polaris, and Jupiter.

Now that the mirror had passed its star testing it was time to decide on a mirror coater, an build a shipping box that I felt confident with. The mirror coater that I had chosen was "H. L. CLAUSING INC.". What I liked about them was their price $35 dollars for a 8" mirror plus shipping costs.

Here is the mirror just before final packing. I made a thick foam insert to hold the mirror an framed that with 1/8" wood paneling for extra support. I covered the mirror in fresh tissue paper an shipped it off.

In just over a week it made it back home in one piece an had a beautiful aluminum coating (actually a Beral coating).

Below is a couple of pictures of the returned finished mirror.


Programming by: Victor T. DeCristoforo
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Last Modified
October 17, 2009