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Gadgets, Gizmos, and Dohickeys => Cutting, Grinding, Polishing => Topic started by: lithicbeads on October 11, 2020, 07:27:30 PM

Title: 12 mm ultrasonically drilled holes
Post by: lithicbeads on October 11, 2020, 07:27:30 PM

I stopped just before break-through on the one hole to show you what we used to look for with the old diamond drilling on big holes  To prevent break-out, we would grind down to meet the rest of the hole, but the ultrasonic doesn't cause break-out.  I'm using a very large ball bit to  chamfer the holes.  Washington jade.

Title: Re: 12 mm ultrasonically drilled holes
Post by: R.U. Sirius on October 11, 2020, 07:41:04 PM

Interesting! Is this setup similar to that used in ultrasonic machining of cameos? Is there an abrasive slurry involved, or the tool comes with fixed abrasive?

Title: Re: 12 mm ultrasonically drilled holes
Post by: lithicbeads on October 11, 2020, 08:58:51 PM

Same tool.The cameos are carved in wax and cast in bronze then the bronze master is soldered to a horn instead of a bit.They form degrades as the bronze bit wears and the ones cut early in the run are considered more valuable. The ground forms are typically chased by a carver after tumbling to sharpen them up for the more expensive ones. It uses a sic slurry and hammers the grit into the stone.

Title: Re: 12 mm ultrasonically drilled holes
Post by: Felicia on October 12, 2020, 09:48:59 AM

Thanks for the article. Interesting to see different tools.