wetRe: [CAD_CAM_EDM_DRO] Looking for CNC Plasma

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "smirob1" <rob@...> wrote:

>
> Hello again,
> Unfortunately, my router table is only 14"x14" and is made of lighter aluminum, and uncapable of handling 1/4" plate.
>
> I've seen some CNC Plasma's with Servo's and Stepper's, but I'm not sure which would be better. I guess, I don't understand how you can get THC feedback with a Stepper.
>
> Anyway, I hope to get some recommendations soon.
>
> Thank you,
> Rob, MI
>
>
>
>THC feedback does not come from the motors unless you are talking about the Z touch-off on a THC that uses torque feedback on the Z motor to "sense" the top of the material (IHS) . It is the arc gap voltage that is the "altimeter" of THC. The THC circuit reads that, picks out a small percentage of change, and uses that to form a Z servo circuit. Note, I did not say it needs to be a servo motor, just that the Z position is based on feedback of a parameter that is proportional to the position.

TOM Caudle
www.CandCNC.com