Almost Finished Grinding

(Day 3 Part 2)

Well, now that we have a consistent and much easier way to check our focal lengths, It was time to get back to the business of pushing glass.

We last left off with a few wets of 25 micron, so that’s where I picked up from. I would do about 2 wets on each mirror then check the focal length. If you recall, back in the hogging out stage I screwed up and made the curve to deep. Well in trying to correct that I again overshoot and made the curve to shallow and my focal length was a bit long.

So most of today’s work was done TOT, with a sequence of ATOT, BTOT, BTOT, ATOT just for fun!

I stayed at 25 micron while I worked on getting the Focal length in check. After about 2 hours of this I was close enough and moved onto 15 micron.

Did about 3 hours at 15 micron checking the focal length frequently, which also corresponded to a cigarette break J

About this time it was again getting late in the day, but I really wanted to do a wet or two of 9 micron, just to see what it would look like. So I did two wets of 9 micron on each mirror, and called it a night.