PMDX Forum

General Category => SmartBOB controllers and dedicated accessories => Topic started by: pedio on March 17, 2016, 05:19:45 PM

Title: Spindle speed capped
Post by: pedio on March 17, 2016, 05:19:45 PM

I am getting a message in the history box that states "Spindle speed 1 RPM bumped to min PWM duty cycle (5%, 5 RPM). Is this a limitation of the board (PMDX 410  with a PMDX 132 using port 16), smartBOB, or Mach 4?

I am using the spindle to control the laser. I drop the power way down to position the laser to the home on the work piece. 5% can still burn the work piece if I don't move pretty quickly. It would be nice to be able to have a lower power level (perhaps 3rpm)

Peter

Title: Re: Spindle speed capped
Post by: Steve Stallings on March 17, 2016, 05:34:52 PM

The 5% minimum duty cycle is being enforced by the PMDX SmartBOB plugin
based on the value in the "MIN PWM Duty Cycle" box on the Spindle Config
tab of the our plugin configuration dialog. It defaults to 5% but values of
0% to 50% are supported in 1% increments.

If you are using a PMDX-107 or PMDX-407 then 0% is not a workable value
if you use the FWD or RUN outputs of the PMDX-107 or PMDX-407 because
0% duty cycle will cause the spindle FWD or RUN outputs to be turned on.

Title: Re: Spindle speed capped
Post by: pedio on March 17, 2016, 06:03:37 PM

Thanks - It works much better set to 1 rpm. The L-cheapo laser is a dull dot. It does not seem to burn anything.