Need Help!- Diamond turning copper

[breaksyid]

Hi all. I have a job on which I need to achieve a 0.4 Ra surface finish on a bore. It's made out of oxygen-free copper. The bore needs to come out to Ø69.55/69.57mm and it's 104mm deep! Now I've been bought a Ø20mm solid carbide boring bar with a couple of diamond tips but I have no idea when it comes to depth of cut, surface speed, feed rates etc. Diamond turning is all new to me. Has anybody got any ideas where to start?

[breaksyid]

Just in case anybody else comes across something similar, I went with 2500 R.P.M, 0.02mm depth of cut and a feed of 0.015. Oh, and a large lump of plasticine helps! Achieved a finish of 0.12 Ra and roundness of 0.001.

[K&Y]

Originally Posted by breaksyid Just in case anybody else comes across something similar, I went with 2500 R.P.M, 0.02mm depth of cut and a feed of 0.015. Oh, and a large lump of plasticine helps! Achieved a finish of 0.12 Ra and roundness of 0.001.

Considering that I missed this thread when it was initially posted, please let me know if you've got any more questions. Thanks!