Wednesday, July 13, 2016

Fixed: Random intermittent "External E-Stop Detected" in Mach3

The Marietta Makerstation has a 3 axis CNC wood router.  I tried to use it last night, but hit a problem.  The Mach3 software would stop every couple of minutes with an error "External E-Stop Detected."

That was frustrating.

I found a fix for it.  Under the Config >> General Settings menu there is a "Debounce" option in the upper right corner of the screen.  I entered "125" here and this solves the problem.

Explanation:  The router has a lot of electrical noise.  "A lot" is an understatement.  When you turn it on, our doorbell rings.  Occasionally this noise will cause the pc to detect a blip on the E-Stop input pin.  The debounce setting tells the system to ignore e-stop input unless the signal is present for 125 * 40 microseconds, or 5 milliseconds.

Magic.

Here's the first part I've cut on that CNC machine.  It's a backboard for the Wally 3d printer I'm making.