I finished making the base plate on which the mirror sits: 3" diameter 1/2" thick. I really only needed a hole slightly larger than 1/2" in the center to hold it on the outside of the jaws for turning the exterior. I center drilled on the lathe, then used a 1/4" twist drill in the tailstock, then a 1/2" end mill. Next step was trying to use a 19/32" twist drill bit in the tailstock. This was not as successful as I had hoped, so I used the 1/2" hole to center the 19/32" drill bit in the drill press. Then I bored the interior on the lathe to get an even centered hole.
Now comes the next step. Getting holes 120o apart on the face using the rotating table is easy; getting them on the edges, not so easy. For some reason when I bought this rotating table, I was under the impression it would mount on Sherline's tilting table, to allow a right angle use. No, it won't. They do sell an adapter for using the rotating table at a right angle to the bed, but both price and apparent complexity of using it scared me off.
There is a lip on the rotating table that is .385" high. There are two .188" diameter through holes on that lip. I bought some .390" thick hot roll which I will fit on that lip giving me a flat surface to go on the bed, with some T-fasteners to lock the assembly in position. The threaded holes in that piece of hot rolled steel require drilling two .144" holes, then tapping to 8-32. Unfortunately, my drill bit was an older not very sharp one, and it melted in use. I changed sides, but the closest size that might still tap okay is not very sharp (likely the problem that melted the other bit). A much finer drill bit, with the titanium coating sliced right in. I need to buy some titanium tipped .144" drill bits tomorrow.
Conservative. Idaho. Software engineer. Historian. Trying to prevent Idiocracy from becoming a documentary.
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Good point about having at least a couple bits of each size, I have 4 or 5 full indexes, at least of the 1/16 -> 1/2 by 64ths. But, I also have a Drill Doctor that does a good job of sharpening, up to 3/4". But, every machinist should know how to sharpen drills on a bench grinder. There should be some youtube videos.....
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