Limit Switches.... just one?

I am working on a design for a pick and place machine and would like to use just one limit switch on one axis (Z)… is this possible?

X and Y axis have switches at both ends but the Z travel is less than 50mm and my plan was to have one microswitch which gets activated by a cam at the extents of travel, can I do this?

Sure, this is supported / a basic feature, read the Endstops page on the smoothie wiki. Setting the zmax ( or zmin ) pin to “nc” instead of a pin disables it. Or just leave it enabled but don’t wire it, will work also really …

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I think @SimonA is asking whether you can use one pin to sense both min and max, so could the pins for min and max be set to the same pin? (This is a common configuration on LinuxCNC thanks to 5 total input pins on the parallel port.)

Yes that’s right. I have one microswitch which I want to connect. It would be triggered by both min and max so would effectively produce the same signal (opening the contacts) if it were to go all the way down or all the way up.

You can’t do this with Smoothie as far as I know, but if you setup the min ( or max ) endstop and soft endstops, what you will have will be perfectly functionally equivalent.

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