Bevins thanks, yes quite a difference given I only have about 90 pounds moving on the gantry.... It has always stopped dead in its tracks on estop. I think the idea when we set it up was to make sure there were no intermediate circuitry between disabling movement and pressing the button, just a mechanical switch. Switching 5 volts to the drive disable signal on the stepper controllers by the e-stop switch requires a working 5 volt power supply and using an output on the Mesa Card implies that the PC or the board has not hung.
The idea was always to learn how to make a machine so the next one will have a different estop switch that you can add as many switch mechanisms as you want to by clipping them to the back of the switch module.
