End mill depth of cut

[rzw0wr]

Being a newbe I am still trying out how to run my mill properly.

I understand speed and feeds to a point.

How do you take into consideration the depth of your cut and the amount of cutter you are using?

example: .5 dia cutter - .100 deep - .030 pass.

I can figure the Material Removal Rate but it doesn't mean anything to me.

Thanks,
Dale

 

[T Bredehoft]

I wouldn't attempt that on my PM25, but a K&T No 3 should handle it easily.

Its a matter of stability of the machine, not the cutter and the work.

 

[JimDawson]

The MMR really makes no difference unless you are in a production environment, and normally only when running a CNC machine. In the home shop and a manual machine depth of cut and step over is dictated by the horsepower and rigidity of your machine. If your machine will handle it, a full depth and 30% stepover is OK. Maybe the most important is to keep the tooth load in a reasonable range, maybe 0.001 to 0.005 depending on the endmill and material. On a manual machine this is pretty much done by feel, you can feel when the cutter and the machine are happy, even using a power feed.

The MMR even on a small CNC machine can be increased using tricordial cutting strategies that are impossible to do manually.

 

[Bob Korves]

You want to make real chips, not rub the cutter on the work, which overheats and dulls the cutter. You do not want to push so hard that the mill is flexing, jumping and breaking the tool. Somewhere in the middle is the sweet spot. For most work, when I start to feel feedback in the feed handle, it is a good cut. Do not dwell in the cut, rubbing on the work, if it is at all avoidable. Keep feeding instead if you can, or back off the work. Sound, vibration, chips, smoke, color of chips, and more all are trying to tell you how things are going. Speed/feed charts are OK, but they are often made for use on rigid industrial machines with solid setups. Home shop work is often more sketchy...