Identifying lathe collet sizes.

[Plato]

Since I buy most of my tools second hand, especially those relating to lathes, I've ended up with quite a few unnumbered collets:

I only have pin gauges going up to 1mm in diameter and since they can't be measured with a caliper either I decided to use my lathe to measure them properly. I started with a 40mm brass rod and I'm gradually reducing it in diameter in 1mm increments until I identify each of the unnumbered collets; plus, I'm checking the condition of each of my numbered collets at the same time. Not sure if there's an easier way to do this but if nothing else it gives me a bit of practice time on the lathe 

 

[jdm]

4 minutes ago, Plato said:

I only have pin gauges going up to 1mm in diameter

These are good https://shop.vogel-germany.de/test-equipment/jet-gauge-1-50-3-00-mm-16-blades.html

Also available 0.45 - 1.50mm. Apparently discontinued, that is the best price I could find.

[Plato]

18 minutes ago, jdm said:

These are good https://shop.vogel-germany.de/test-equipment/jet-gauge-1-50-3-00-mm-16-blades.html

Also available 0.45 - 1.50mm. Apparently discontinued, that is the best price I could find.

Cheers, I was expecting them to be far more expensive, I'm just assuming watchmaking tool prices!

Any ideas how to permanently engrave the sizes on the collets? I've got a Dremel engraver but if there's a better tool/method...

[jdm]

1 hour ago, Plato said:

Any ideas how to permanently engrave the sizes on the collets? I've got a Dremel engraver but if there's a better tool/method...

Maybe photoetching? I've never tried myself, happy enough with a label printer and clear tape.

 

[nickelsilver]

Keep in mind that the fact that a pin fits doesn't mean that's the size of the collet. They are usually sprung slightly open as made, and you can fit say a 2.1 pin in a 2.00mm collet- but it won't close correctly, run true or securely.

 

 

[Plato]

18 minutes ago, nickelsilver said:

Keep in mind that the fact that a pin fits doesn't mean that's the size of the collet. They are usually sprung slightly open as made, and you can fit say a 2.1 pin in a 2.00mm collet- but it won't close correctly, run true or securely.

 

 

OK, maybe I'll just label them with permanent marker for now. I've been measuring them by making sure they go on freely and then hold with just pressure from gripping the end with my hand. So, my '25' could be actually a 24.

My method is flawed but I do have a general idea of the size, I'll just have to remember my numbering could be off when it comes to using them proper. Cheers.