Grinding Glass: new lap, and a lathe!



You may need to download Quicktime for Windows to view the above slides how (.mov format)

A new tool!

It has been a LONG time! Last post was September 23rd! Not good. It was a busy Fall season at the Museum so weekends were pretty full. But I have had microscope building on my mind.

I have been reading "Darwin and the Barnacle" by Rebecca Scott, I enjoyed it from the observation side and thinking about the improvements in microscopes being used and how these tools and careful dissection allowed for rethinking of how various species were related. Similar stories are being repeated these days with molecular data. The barnacles have an amazing variety of reproductive strategies! I di dfind myself wishing for more detail on exactly which microscopes were being used but it was good. I also enjoyed the stories about Darwin teaching others how to use microscopes and make detailed observations.

I also took the leap and purchased a Sherline lathe and a collection of accessories (some images above). I am almost ready to start working on some brass. But I am doing one last glass project. Sandro made a couple laps out of cast iron after I wore out the aluminum one. This is very similar, but we went for a slightly wider radius shooting for slightly lower magnification that might work nicely with insects and some small plankton. Something close to 40x I hope. Sandro used a "Ball Nose Cutter" to make the spherical dimple in the lap, this was because we would probably not produce good results hammering a ball bearing into cast iron. I did shatter one ball bearing working on the aluminum.

So I had a chance on January 1st (treadling in the new year) to use the cast iron lap to shape a lens, I was not rushing and it probably took about 1 1/2 hours, I was not looking at the clock. Everything went very well using the sealing wax instead of the canada balsam was great, no softening and lenses coming off the rod. I am now working on the polishing lap using the worn aluminum lap. I was working a 1/4 ball bearing into the sculpting epoxy with my fingers, and that was not the way to go, but at that point I could not bond the ball bearing to a rod. The metal of the bearing was cooling the sealing wax too fast and they were not bonding together, and using epoxy or canada balsam would not bond fast enough... I think I might start over, maybe some crazy glue. The problem was that the bearing would stick to the sculpting epoxy and then it was difficult to pull the bearing away without deforming the polishing surface.

January 4, 2013

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