From your pic, is this the machine?
R-5030 Model in Ares-Seiki Tapping Machinery
That's only a 30 taper; they have notoriously weak pull studs; it's easy to snap one, which can result in ruining the spindle taper. I would NOT advise running a 3" facemill in steel on a 30 taper unless you REALLY know what you're doing, and then you'll be limited to shallow passes.
Nice grab my fiend...that is the exact machine in question.....I have a question aside from this deal..Wouldn't a simple .04 in face mill pass on this machine work if done at 100sfm and and a proper chip load.?
I wonder what the actual reasoning was with the instructor...why would he do this and think it would be ok?
I've learned a ton from my machining tech instructor, but we are working on cnc stuff now and it seems he just wants to break world records. I have some CAM experience and watching these young 20 yr olds be instructed to run at max rpm is worrying to me. Maybe I am wrong, that is why I post this issue.
We have a basic small vertical mill with a bt-30 holder and 4-5 horsepower spindle that can run 10,000rpm and weights roughly 2500 lbs. A student always asks me questions on CAM b/c the instructor is an old school hand programmer at heart. I always tell him to try steel at 200-300sfm for our HSS cutters and limit the cut to 15% radially. Today, the instructor tells him I am wrong and to run the 3/4" HSS endmill at max rpm(10,000), b/c we are only cutting at .4 doc. This is still 2000sfm and it is 1018 steel. Then they laugh when I say the .780 slot is going to be quite the experience at 160ipm and 10K rpm with a .75 HSS cutter. Part of the issue is the part is only 4 inches long so many features the machine can't get up to speed, unless I'm wrong on the acceleration...
Anyway, I put my foot down this morning and told them I thought this was wrong. I suggested students should be running parts at 200-400 sfm in steel. I was told I was wrong and parts shouldn't be run with 6 spark plugs pulled out of the engine. I don't have real world experience, but I care about what is right and the students. Am I wrong to fight against 2000sfm in steel?