You say you don't have tools to measure tolerance, and then say your tolerances are sub micron?
I said I have no tool to measure tolerance of roundness I get on the lathe. Dial wiith 0.001 mm precision shows nothing on just turned part. So you need more precise measurement device to measure roundness tolerance less than 0.001 mm. I don't have such, so can't tell what exact value I have, only that it is less than 0.001 mm.
What stone are you working with?
Roundness tolerance does not depend on material. It's a property of lathe, not stock.
You can only lathe granite with carbide or diamond impregnated steel.
Nor diamond, nor carbide never impregnated into steel. That's not how abrasive cutting tools made. Just visit hardware shop and look at cutting disks for ceramic, concrete and stone. Abrasive impregnated into brass or bronze layer.
To cut some stone you need abrasive with equal or larger hardness. So you could just use granite itself to cut granite. Just have to change tool more often. Also, granite hardness is less than SiO2 hardness. So you could use sand as abrasive too. Guess what is used to cut diamonds? Siddenly, diamonds.
A lathe, even with the proper tools, puts lots of pressure on granite
You don't need to put pressure on granite. You need to have a fast rotating disc with abrasive as a tool, not a cutter.
Lathe is not a mechanism to put pressure. Lathe is a mechanism that allow turning round things with some tool. Potter's wheel is kind of lathe too. Tool is your hand in that case.
You can't just eyeball that.
You don't need to. Take something round as a template and you will be able to create enormous amounts of interesting curves, just combining circles. Different round templates will make things more interesting.
You seriously think the ancient Egyptians created micron tolerances in granite with lathes made out of "arrowheads" and "bowstring"
You get micron tolerances because of rotation between two supports. Not because of what that supports are.
Egyptologists claim the ancient Egyptians didn't have brass or bronze. They claim they only had copper and stone tools.
If you are not aware, it is much harder to make copper, than to make bronze. Bronze is just impure copper, with tin, silicon, lead and so on as impurities. To make copper you need more advanced technology than to make bronze.
You do know that it's the Egyptologists themselves that say the ancient Egyptians created these vases with only copper chisels, and without lathes?
I don't care what Egyptologists say. Imagine that. I don't need any Egyptologists to find out how things could be done by ancient people.
You seriously think the ancient Egyptians created micron tolerances in granite
There is nothing exceptional in "micron tolerances" at all. A surface, glossy enough to be a mirror have less then 0.1 μm roughness. Yes, 100 nm tolerance. Ancient Egyptians had nanotechnologies!!!111
It requires carbide or diamond impregnated steel
Why do you continue to repeat that bullshit about "abrasive impregnated steel" ? It is very easy to check that abrasive is always impregnated in bronze or brass even in modern instruments. Steel is used only as a cheap base for abrasive impregnated bronze. Steel is significantly cheaper than bronze today, so no need to make whole tool from bronze, and only cutting edge made from bronze now.
Those "coins" couldn't do jack shit to granite.
Those "coins" are as good, as modern diamond disks for Dremel. They just lost all abrasive on the edge, so was thrown out as we found them or was used as they are with abrasive suspension pouring on the rotating disk.
The entire society/civilization would have to shift/advance to achieve those increases in precision.
Strange that you do not apply same logic to your "unknown advanced ancient technology" belief. If ancient Egyptians had some advanced tech, then they had to have industry to make that tech, to make parts of that tech and so on, including precursor tech, parts, etc. And it had to be massive, so we had to find weared and spare parts of that advanced tech and tools to make that advanced tech everywhere in ancient Egypt.
You can't have tech, even magic or alien one without any traces. If it is magic, then there should be tons of blank magic wands, tools to make magic wands and so on. If it is alien, there should be tons of weared alien tool parts, depleted or broken energy sources, broken tools and so on.
When you have only a vase made with "advanced ancient tech", but no any traces of that tech at all, then it is bullshit. So, to be honest you have to look around and see if that vase could be done with things ancient Egyptians already had.
If you think that I'm kind of hardcore sceptic, you can't be wrong more. On the opposite, for a lond I'm trying to find any evidence of any "out of nowhere" technology, because it would be a solid proof of some external, alien influence on development of humanity. But none of that "advanced ancient technology" claims I know about, ever demonstrated technology itself or its parts, only some artifacts claimed to be done with "advanced ancient technology". And all those artifacts perfectly possible for the time they attributed to.
There is a group of "out-of-time" or "out-of-place" artifacts, like that spark plug ingrown into stone, but they are too questionable and too obvious. Antykitera mechanism was kind of promising, but it appeared to be just a sophisticated mechanical calendar to show events and holidays of ancient Greece. Interesting, but not what I looking for.
Listen, If there would have been found something like Antykithera mechanism, but designed to show phases of three moons and dates for completely another planet - THAT would be something I looking for.
Or if there would have been discovered multiple complex but definitely compatible parts of some tech with unknown purpose and with nothing even close to anything in our technologies, then it will be also very interesting.
If you know something like that - you are welcome.
So, if you satisfied with consuming what some videobloggers or "Egyptologists" tell you for your amusement, then fine. Many do that. But I'm not from their target audience. I want real proof.
I said I have no tool to measure tolerance of roundness I get on the lathe. Dial wiith 0.001 mm precision shows nothing on just turned part. So you need more precise measurement device to measure roundness tolerance less than 0.001 mm. I don't have such, so can't tell what exact value I have, only that it is less than 0.001 mm.
Roundness tolerance does not depend on material. It's a property of lathe, not stock.
Nor diamond, nor carbide never impregnated into steel. That's not how abrasive cutting tools made. Just visit hardware shop and look at cutting disks for ceramic, concrete and stone. Abrasive impregnated into brass or bronze layer.
To cut some stone you need abrasive with equal or larger hardness. So you could just use granite itself to cut granite. Just have to change tool more often. Also, granite hardness is less than SiO2 hardness. So you could use sand as abrasive too. Guess what is used to cut diamonds? Siddenly, diamonds.
You don't need to put pressure on granite. You need to have a fast rotating disc with abrasive as a tool, not a cutter.
Lathe is not a mechanism to put pressure. Lathe is a mechanism that allow turning round things with some tool. Potter's wheel is kind of lathe too. Tool is your hand in that case.
You don't need to. Take something round as a template and you will be able to create enormous amounts of interesting curves, just combining circles. Different round templates will make things more interesting.
You get micron tolerances because of rotation between two supports. Not because of what that supports are.
If you are not aware, it is much harder to make copper, than to make bronze. Bronze is just impure copper, with tin, silicon, lead and so on as impurities. To make copper you need more advanced technology than to make bronze.
I don't care what Egyptologists say. Imagine that. I don't need any Egyptologists to find out how things could be done by ancient people.
There is nothing exceptional in "micron tolerances" at all. A surface, glossy enough to be a mirror have less then 0.1 μm roughness. Yes, 100 nm tolerance. Ancient Egyptians had nanotechnologies!!!111
Why do you continue to repeat that bullshit about "abrasive impregnated steel" ? It is very easy to check that abrasive is always impregnated in bronze or brass even in modern instruments. Steel is used only as a cheap base for abrasive impregnated bronze. Steel is significantly cheaper than bronze today, so no need to make whole tool from bronze, and only cutting edge made from bronze now.
Those "coins" are as good, as modern diamond disks for Dremel. They just lost all abrasive on the edge, so was thrown out as we found them or was used as they are with abrasive suspension pouring on the rotating disk.
Strange that you do not apply same logic to your "unknown advanced ancient technology" belief. If ancient Egyptians had some advanced tech, then they had to have industry to make that tech, to make parts of that tech and so on, including precursor tech, parts, etc. And it had to be massive, so we had to find weared and spare parts of that advanced tech and tools to make that advanced tech everywhere in ancient Egypt.
You can't have tech, even magic or alien one without any traces. If it is magic, then there should be tons of blank magic wands, tools to make magic wands and so on. If it is alien, there should be tons of weared alien tool parts, depleted or broken energy sources, broken tools and so on.
When you have only a vase made with "advanced ancient tech", but no any traces of that tech at all, then it is bullshit. So, to be honest you have to look around and see if that vase could be done with things ancient Egyptians already had.
If you think that I'm kind of hardcore sceptic, you can't be wrong more. On the opposite, for a lond I'm trying to find any evidence of any "out of nowhere" technology, because it would be a solid proof of some external, alien influence on development of humanity. But none of that "advanced ancient technology" claims I know about, ever demonstrated technology itself or its parts, only some artifacts claimed to be done with "advanced ancient technology". And all those artifacts perfectly possible for the time they attributed to.
There is a group of "out-of-time" or "out-of-place" artifacts, like that spark plug ingrown into stone, but they are too questionable and too obvious. Antykitera mechanism was kind of promising, but it appeared to be just a sophisticated mechanical calendar to show events and holidays of ancient Greece. Interesting, but not what I looking for.
Listen, If there would have been found something like Antykithera mechanism, but designed to show phases of three moons and dates for completely another planet - THAT would be something I looking for.
Or if there would have been discovered multiple complex but definitely compatible parts of some tech with unknown purpose and with nothing even close to anything in our technologies, then it will be also very interesting.
If you know something like that - you are welcome.
So, if you satisfied with consuming what some videobloggers or "Egyptologists" tell you for your amusement, then fine. Many do that. But I'm not from their target audience. I want real proof.