What spindle RPM are people using with the Tormach T/C tapping head (# 32020)? I'm mostly interested in using 2-56 and 4-40 spiral point taps in thru holes in 6061. I'd also like to try thread forming taps with the T/C head.
I've seen recommendations of 500 rpm. This is a problem on my 770 since I mostly use small cutters so I keep the mill in high range (525-10200 rpm). If I have to change belts it is faster to tap a couple of holes by hand!