Hello All,

I'm going to do some 3d profiling in some 7075.

I've got generic 3 flute carbide ball nose end mills.

I've got a Haas VF2 with a 10K spindle. All tools will be mounted in ER32 collets.

I think I'll rough it with my 1/2" ball nose. Speed at 10K rpm and feed at ~100 IPM. Depths of cut will be max 3/8" max width of cut will be 1/4"

I then will semi rough with my 1/4" ball nose. Speed at 10K and feeding at ??
I will leave about 10 thou so it will not be cutting much at all, however in the 'tighter' places I'm not sure how much will be left as the 1/2" may not be able to get in. Could I conceivably feed this at ~100 IPM? (I'll be stepping over at.. 25 thou?)

I will then finish with a 1/8" ball nose. Speed again at 10K and feeding at ??

I think I'll only leave a couple thou for this guy. No idea what type of feed it could manage. This will be a very fine stepover (5 thouish)

I have 2 of the 1/8" otherwise I only have 1 cutter so I really don't want to destroy the 1/4".

Could I skip the 1/4" completely? I also have 1 1/16" ballnose perhaps I should use that?

Thanks!

Bump, I'm going to 'mastercam' the part tonight!

Take a look at some speed/feed charts from an endmill manufacturer

Your feed is derived from chipload, # of flutes and RPM.
Use a manufacturers recomended chipload and do the math.

Your chiploads will likely reduce by half every dia you step down, But your small DOC and stepover will bring the feeds back up a bit.

All corners should be cleaned out to uniform stock with roughing MOps before the final surfacing pass.

I have ran a 1/4 carbide 2 flute ball at 80 IPM at 10000 RPM with a .0136 step over. Removing .020 to .030 stock max.

[If I was to use an 1/8 carbide ball endmill, I would use 56 IPM at 10000 RPM using a .0096 step over.]