Re: AC Motor Speed Control

--- In CAD_CAM_EDM_DRO@yahoogroups.com, R Rogers <rogersmach@...> wrote:

>
> Dave,
>
> The G-series of VFD's from automationdirect have "auto torque

boost" for low RPM operation. Just one of the many many variables that
can be adjusted to accomodate almost any application. Even dynamic
braking. The biggest problem with low RPM operation is cooling, the
motor's cooling fan just doesnt rotate fast enoough to have much
effect. An external constant speed cooling fan on the motor would help.

>
> Anyways, I just set a VFD up on a 8x36 Jet with Mach3 and Bob

Campbell's spindle speed board, 2 hp 3 phase dayton motor.

yikes. my 9xlathe is listed for use with a 1/4 hp motor and people
are worried when using 3/4 hp. Even with yester years' 50% more power
from the older style motors, 2hp is quite a jump up. I would expect
you to have lots of torqe from that.

I think that a quick change pulley for that hi/lo makes a lot of sense
in conjunction with a VSD.

My pretty crappy set-up with it's VSD is VERY convienient even with
the poor performance.

Dave