4040 Pro Max Easy Prox Sensors

Easy at least for the two Y axis front sensors. The rest, not so much. Plus gain 30mm more Y+ travel compared to the factory limit switch.

I’m replacing the factory mechanical limit switches with inductive proximity sensors. A sensor for each end of each axis except for the right side Y axis. Only adding a single sensor on the front (+) of that axis that will enable auto Y axis squaring in Fluidnc. That’s 7 sensors total.

I noticed the front of the Y axis rail and leadscrews mount has an odd shaped hole in it. It’s round in the center and appeared to be about the same diameter as the sensors I have so I removed the mount face plates to check it out. Turns out the holes are a perfect size for the sensors! The rear nut on the sensor doesn’t have a full area to seat but there’s a ledge that provides plenty of area to tighten the nut.

https://www.amazon.com/gp/aw/d/B073XDWWHW

I setup the FluidNC config.yaml for the new sensors. I left the factory switch on the Y left rear as a hard limit. After performing a home operation I measured the distance on each side of the Y axis for squarness. Amazingly there was only 0.3mm difference. I edited the homing pull off setting in the FluidNC config file for one side and homed again. Perfectly aligned! I tested several more times including manually turning the leadscrew on one side making the two Y axes off square. Homing squared them up every time!

All the other sensor replacements will have to wait for another day.