Re: RF-45 Mini Bed Mill

In a message dated 08/30/1999 5:21:05 PM Hawaiian Standard Time,
dfalck@... writes:

<< 5. Installing a big (1 HP) Baldor PM DC motor to run the spindle, so that
I can control speed and orientation (for future tool changer) with the PC. >>

Dan,
Can you order the thing with a three phase motor? I didn't ask when I
ordered mine. If you can, a VFD may be an easier way to interface to the CNC
Controller. Many VFDs have the same +- 10 volt input as a servo. This allows
the CNC to walk the spindle into correct orientation with the use of an
encoder. Looks like they are using some kind of face mounted motor but I
can't tell if it is a 56 C type or not. I don't know what the torque curves
of your DC motor is but I know in VFDs, they often spec a motor twice as
large in Hp as a single speed setup to get adequate grunt when running at low
RPMs. I may end up installing a Precise 60,000 spindle on mine. Otherwise, I
should have thought of the three phase motor too! I was gonna go with .750 X
.200 screws. What size are you going with?
Peter