CNC Tooling

[DampRobot]

Originally Posted by DonRotolo

DampRobot, 6 IPM is 1" in 10 seconds, or 0.1" per second. Just seems slow to me, but....

1. You're getting good results. Something must be right, eh?
2. What kind of depth of cut we talkin here? 0.1" or 1/2"? That matters...

Anyway, I keep looking at #1 above and concluding it's OK.

I remember vaguely that the tool moved about one tool diameter every two seconds (for a 1/4" tool) when we were cutting quickly. That gives a feed rate of 7.5 IPM, which squares fairly well with the 6-10 value I remember. I recall it seeming quite fast, but I guess it's all relative.

We have got results we're pleased with. We don't have to deal with anything as intensive as flood cooling, and we don't feel like milling something takes too long (setup and tool zeroing still dominates the time spent on the mill). With a 1/4" tool, we usually wouldn't cut anything thicker than 1/4" alu plate at that speed. Stuff on the 1/2" or larger scale we would use a larger cutter (1/2" or something) and probably even do in multiple passes, depending on the geometry and the tool. With 3/16" tools or smaller in 1/4" or even possibly 1/8" material, we'd take multiple passes too, just to be safe.

Since others have shared their advice about cutting faster (in the 20-60 IPM range), I'll definitely make a point of trying it. Cutting faster is always good, as is better tool life, etc. Since we do make good chips and cut quickly enough for our tastes at our current speeds, if we don't have success with the higher speeds, we'd be happy going back to what we're more familiar with.

Thanks to everyone for their experience and suggestions. I'll post again in this thread when I get a chance to experiment with the speeds on our mill.