On my machine I have an estop on my control box and on machine frame. I designed mine so when I hit the switch power is lost to everything except the breakout board (Campbell). The breakout board has an e stop relay built on it and sends the signal to mach 3, this is done by effectively shorting two pins. I put a NO relay across these pins which is controlled from e stop relays in the supply I built. When the stop is hit the high potential is drained from the supply and the motors very quickly through a high wattage bleed resistor. Power to the spindle and extractor is also cut. If I can find my circuit schematic i'll put it up. |