Re: [CAD_CAM_EDM_DRO] What variable speed motor to use?

Gerald <Area51tats@...> wrote:

>
> Does anyone know of a smaller and way slower DC motor and controller? I want
> to put a power feed on my sherline lathe and I would like variable speed and
> cw/ccw rotation. Thanks

Ok, there are two different strategies going on in this discussion:

#1- One is to take an AC motor, stick a VFD (variable frequency drive)
electronics box on it, and there ya go, a manually knob adjustable
rpm motor. Just great for a mill, or for a manual lathe.

#2- The other (more expensive, but very useful, and very applicative to
lathes)
situation is to replace the AC motor with a DC
motor/encoder/servodrive
combo and put the rpm (and indeed the exact spindle position) under
control of the PC.

This allows, not only threading, but also CSS (constant surface
speed)
cutting (as the radius of the workpiece shrinks due to material
removal,
the rpm goes up). This is desirable because it optimizes the life
of
the tool, and minimizes the cycle time (the time to produce each
piece).

So we should really restrict the 'solutions' to the problem at hand.

Actually, in Geralds case, where he wants variable speed (of the Spindle
I assume) he has to tell us if the rest of the machine is manual
(solution #1 above) or to be CNC (solution #1, or for full optimization
solution #2).

Doug Fortune
http://www.cncKITS.com