Originally Posted by
Brady Watson
Here's the *official* word from both spindle manufacturers:
I start my spindles as low as they can go and just let them sit. The 5hp and 3hp Colombos run at 1000 RPM in a cold shop for a few minutes and I graduate from there. The HSD on the DT runs at about 2500 (less and it stalls/doesn't like it) and also gets graduated in RPM over time.
Note that the SB speed control will not permit RPM lower than 5,000. If you like rolling manual like I do, you can spin it down as low as a few hundred RPM on the larger spindles.
-B