Ancient precision

[oil pan 4]

Originally Posted by ME_Andy

Possibly an acid drip? Again, to explain some of the cutting lines in oilpan's link

Sounds like a repeatable testable experiment.
Figure out what acids they could have had and run it.

[ME_Andy]

If I had tons of time on my hands, I would. Seriously.

[freebeard]

Sounds like a repeatable testable experiment.
Figure out what acids they could have had and run it.

Start with aqua regia.

The better question is how you control the drip to an accuracy that can be 'zero point zero' on modern measuriing equipment.

[ME_Andy]

Possibly you could use taut twine to guide the first pass, until it creates a groove. Then it gets easier.

[Piotrsko]

Wont get "zero point zero" in any repeatable fashion in rock or fired stoneware. The drill point is going to hunt a bit by flexing until it finds a start point unless it is larger than 1/4" diameter and you use ridiculously slow feeds with a dull, hard as heck point. You could drill off center and process a correction in, but, that may not be that accurate or repeatable. Definitely not using ancient processes because they couldn't measure to those standards to determine if it's off dimension in the first place. Ditto for lasers and other stone removal.processes.

I can tell that none of you have any stone experience manufacturing items

[freebeard]

Definitely not using ancient processes because they couldn't measure to those standards to determine if it's off dimension in the first place

And yet the objects exist. Whatever the method, the speckled diorite has inclusions that are softer [or harder] than the surrounding material.

[redpoint5]

Ancient precision is fine, but it's nothing compared to a 5nm process producing billions of transistors allowing a wristwatch way more feature rich than even Dick Tracy could predict.

[Piotrsko]

And THAT'S repeatable. All day and night long, 24/7/365.25