anyway, the x axis limit switch used to work, now it does still switch, turns the led on and off on the breakout board - usb leafbox 200 hz xulifeng  thing

but it doesn't bounce back = stays in the emergency stop mode if you like on homing, I then have to switch it all off and pull the axis away from the switch to get going again.

do I adjust the switch mechanically - or is there a setting I can alter

I did have to set the kernel speed to 45000hz to get ot going, as its didn't like 25000 - just wiggled about a bit.

any suggestions? - move the switch forwards?

thanks

Probably an issue with Win 8.1 and the USB port interrupt timing. Unless there is some compelling reason to use Windows 8.1 I would suggest not using it for Mach 3. Mach 3 runs very well under XP. Windows 8.1 is a bloated OS. There are plenty of used XP machines on the market cheap. There is no practical reason to upgrade to Windows 8.1 for running a cnc machine unless you want to watch Youtube videos or check your email at the same time.

Hello please, I have had it working, I have cut something today.
whats the interrupt all about?