I was just in visiting with a customer that has 4 new HAAS machines, 2 lathes, 2 mills. The lathe has live tooling and a C axis, the live tooling uses an optioned up motor to 7.5 HP.

These questions pertain to live tooling.....

Can someone tell me their experiences with drilling (along the Z axis, good bad etc.) ?

What size HSS drills have you used in mild steel?

What about the largest taps you have used reliably?

Thanks

not really diy but man if you want to drill hole patterns
in a turned part it's awsome!!

we use carbide/Ti nitride tools...

as an example, we turned a part with a threaded OD and a
circular hole pattern of eight holes, each hole (including indexing the chuck)
took about 12-15 sec-

i did it a long time ago on a manual centre lathe and it took about 3 minutes

sounds like a very powerfull rotary tool spindle motor.
i have tons of experience with programing/setup okuma,hitachi,,and lots of other cnc's with rotary tooling.
max drilling dia with rotary tooling-25mm(1")with a pilot hole first,mat S1214(similar HP).
plunge milling into the face using 25mm(1")multi tipped carbide milling cutters,
i would use cad/cam for the plunging cycle and of coarse using the polar corordinate/contour generation function in the cnc.
largest tapping size i can think of is 1/2 UNF into K1045.(ridgid tapping,not floating).
drilling,tapping,deburring and milling in cnc lathes is very productive,
check the parameters in the cnc for tapping speed double in reverse option,this really gets the cycle time up when you double the speed when the tap comes out of the hole.
try and use carbide drills/milling cutters if the rotary toold are ridgid enough.
hope this helps