[sarahn27]

I don't have any experience with micro-machining, and I need to drill some small, deep holes (1/32 diameter, 0.64" deep) in ABS and I'm having some trouble figuring out how to do it. My machine specs are below:

Model: Acer E-Mill 3VS II Vertical Turret Mill
CNC Retrofit: 3-Axis Acu-Rite MILLPWR G2 CNC Retrofit Kit
Max RPM: 4500

I'm currently using a 1/32" diameter 60 degree spot drill as a pilot hole and countersink, and then following that up with a 1/32" HSS drill. I've been drilling some of these holes manually to test them, but eventually I'll have to use the mill's CNC capabilities, since there are about 100 of these holes in the final part. The issue I'm having is that chips keep getting stuck in the hole, and then cause the drill bit to deflect, which redrills the hole in a slightly different location, at an angle, before breaking.

Is there a best way to do this? Any tool recommendations would be greatly appreciated. Also what would the best feeds and speeds be for this operation? My mill only goes up to 4500 RPM so that's the max I can do.

[awerby]

You might try using a peck-drilling cycle instead of trying to do this in a single plunge. Peck drilling involves retreating out of the hole after a short plunge, which breaks the chip and clears the hole, after which you go a little deeper and repeat.