Re: [CAD_CAM_EDM_DRO] VFD for series 1 bridgeport

bjapundza wrote:

> The machine is missing the air-powered spindle control. I know very
> little about how these devices work. Thinking out loud, would it be
> possible to build a stepper-driven speed control that could be
> interfaced with EMC?

Yes, I think so. I would use the FASTER and SLOWER outputs from
bridgeportio (that used to control the pneumatic valves that ran the air
motor which changed the speed in the original design) as inputs to a
circuit that would start a 555 timer running in bistable mode (to
provide step pulses at a rate determined empirically), and controlled
the direction bit (one way if FASTER, the other for SLOWER). Sorry to be
so terse, but time is short today. Save this message and once you're
familiar with the EMC software it will make more sense.

Matt