I typically run my taps at 500 rpm in aluminium and I run all form taps. I just use that setting for all taps from 2-56 thru 1/4-20 and I don't ususally have to run bigger taps than that.
At any rate, I have a job running now that needs 1000 2-56 holes tapped 0.3" deep. The cycle works great at 500 rpm as usual, but its taking up a lot of the % of the cycle time. So I went and increased the rpm.
I was reading in the fadal manuals about tapping at 2000 RPM.
I conservatively tried to run at 1500 RPM; the spindle freaked out, and threw a c-axis overload fault. This is disappointing considering the manual lists 2000rpm like its casual to do so (no max speed stated as far as I found in the manual so far.. will keep looking).
So, I tried again at 1000 RPM, and it worked, but it seems jerky on reverse where the spindle speed overshoots, then undershoots, then levels out. By the time this all happens, the hole is finished, and probably has loose threads. I tried a screw in the hole and couldn't get it to strip out at all / my allen key slipped before the screw would strip the hole - so it seems like a good tapped hole despite the spindle control ringing.
I backed it off to 800 RPM, and have been running fine all day, even if the spindle is slightly ringy, and the cycle time improved thusly.
Any thoughts out there? I have a 20 HP high torque 1992 VMC 4020, and it has a newer / replaced drive - it now has a blador H2 vector drive. Is there some control tuning I can do? Last time I tried messing with that baldor H2 I ruined by low speed belt - so I'm pretty hesitant to go pressing buttons on that drive without knowing exactly what to do.