Question re: Dual endstops with the Ramps board

A noob questions re: dual endstops with the Ramps board:

On your dual endstops page you say “For the safest configuration the endstops should be wired in the Normally Closed position (NC), to prevent wire disconnects from damaging the machine during the homing sequence.“.

My question is how do you do this? Is this a wiring thing on the endstop switch itself or some sort of programming setup???

I have attached a photo of my endstop switch. I assume the green wire is signal and the black wire ground?? I don’t use the red wire – is that correct??

Or do I de-solder the switch off the board and just use the switch on it’s own and wire to the COM and NC pins?

Both, you have to wire the endstop correctly and the default configuration can be changed in firmware if you want it NO.

No photo actually attached, but you attach a wire to the NC pin and another wire to the COM pin, then connect the other ends to the ramps board. There is no polarity as it is only a open/closed circuit.


Photo added of my endstop

Based on the schematic of the makerbot v1.2 endstop (which this appears to be), green and red should be NC and green and black should be NO. Personally I would desolder it (or cut it off with wire clippers, should be enough tab to still use) and just use the switch, then you can use Ryan’s conduit clamp to hold it. (There are other clamps on thingiverse too I believe.) I wired mine with a 3-pin header and soldered to NC/NO/COM just in case I needed to switch from NC to NO later.

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