Next jewel installment: The Levin compound has a receiver for several attachments. The hole grinding and polishing jig I made myself, the little grinding head came from somewhere, and I adapted it to the receiver.
You will notice that the jewel is already polished flat on top and round on the sides; it is the same process as the rough grinding in the last post but using 1200 paste on different lap. First I bring the hole out to nearly the pivot diameter, checking with gauge pins. This goes pretty quickly, and I have changed to 1200 paste in the second photo. It will still increase the hole size as it smooths out the inner surface. I clean and check the hole, and add paste many, many times in this process. The polishing head is swung around so that the acting surface of the tapered lap is parallel with the hole. The working surface should rotate against the direction that the inside of the hole is turning. The small laps are made from copper wire, and are threaded into the end of the shaft. I have assorted sizes, ranging from #8 copper ground wire through #14 copper house wire. These are used for polishing lots of things.
Next I grind the oil sink and smooth it with 325 paste on one of the larger copper laps. Later I'll polish it with a shaped piece of pegwood charged with 1200 and then 14000
After the process of smoothing the sides and face, I'll chamfer the end I'm working on. This actually occurred prior to hole grinding and polishing, just after the second polishing of the sides and face of the jewel (not documented), and while the polishing head was still in the compound.
At this point I'm ready to make jewel chucks for holding the jewel to polish the other end, and to final size and polish the hole.
That will come next.
Johnny

You will notice that the jewel is already polished flat on top and round on the sides; it is the same process as the rough grinding in the last post but using 1200 paste on different lap. First I bring the hole out to nearly the pivot diameter, checking with gauge pins. This goes pretty quickly, and I have changed to 1200 paste in the second photo. It will still increase the hole size as it smooths out the inner surface. I clean and check the hole, and add paste many, many times in this process. The polishing head is swung around so that the acting surface of the tapered lap is parallel with the hole. The working surface should rotate against the direction that the inside of the hole is turning. The small laps are made from copper wire, and are threaded into the end of the shaft. I have assorted sizes, ranging from #8 copper ground wire through #14 copper house wire. These are used for polishing lots of things.


Next I grind the oil sink and smooth it with 325 paste on one of the larger copper laps. Later I'll polish it with a shaped piece of pegwood charged with 1200 and then 14000


After the process of smoothing the sides and face, I'll chamfer the end I'm working on. This actually occurred prior to hole grinding and polishing, just after the second polishing of the sides and face of the jewel (not documented), and while the polishing head was still in the compound.

At this point I'm ready to make jewel chucks for holding the jewel to polish the other end, and to final size and polish the hole.
That will come next.
Johnny
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