ON topic - small hole drilling Ultem

Clay:

I'd use machine max RPM and a feed of .001 per revolution. That would be like 10 IPM @ 10k RPM. I'd peck 1/2 tool diameter at a time. Retract all the way out of the hole and rapid back in to within .005 of the bottom of the previous peck, and feed from there. Try it in a piece of scrap first if you're worried about breaking a drill. And this is WITH coolant to help flush the chips off the drill and to keep the plastic from melting.

Might high pressure coolant help with chips/strings?

DT:

I'm of the opinion that a more aggressive feed, and smaller pecks will help with the stringy bird's nests. It's also within the realm of possibility that a sufficiently high pressure coolant flow directed at a .010 dia. drill might deflect it.

I like the idea of the smaller pecks- smaller chips.. Coolant is not blowing the long chips anywhere, but rather causing them to stick to each other better. Air works, but not real practical.

How do you get it to rapid incrementally deeper in a milling drill cycle? I've done it on lathes, but forget the cycle. Is that a G73/G74 cycle?

clay

Clay:

A G83 deep hole drilling cycle is what I use. BUT I think this can break down into two questions. One; Do the canned drilling cycle options in your specific machine control do what you want? And Two; Does your CAM system make use of those options, without having to create a macro or alter the post?