MPCNC MK8 extruder induction probe mount

You can probably guess from the title, eh? More info:


I’m not familiar with induction probes - is it used to set the tool height? How accurate is it?

It sets the Z-height over the work surface. Even better, when used with Marlin firmware it will probe the bed heights at the corners, build a new “virtual work plane” to use as the work surface and then automatically compensate for any unlevelness of the bed by dynamically adjusting the Z-axis as it traverses the bed.

A level bed is key factor in 3d printing. Sometimes jostling the bed (often when removing a finished print) will knock your bed out of whack. So induction probes have become popular additions, but they are not always necessary.

My printer is built on a sheet of plywood so I can move it. The actual bed is aluminum. Movement and flex of the underlying plywood can cause the bed to shift ever so slightly as it is moved around the shop, so I added this to save me a lot of trouble maintaining a level printing surface in reference to the extruder.

Here is good video about setting it up.

I have one of these on my 3d printer and it is pretty slick and works well with a metallic bed, mines heated aluminum. It isn’t really a solution for milling/routing though because our tool lengths aren’t constant so the Z offset changes with every set-up/tool change. A probe clipped on the tool conducting against a metal touch plate is a good method to use. The touch plate thickness is constant so that can be used to offset your Z axis instead.

@Karl- Do you have a touch plate set up already? I used to have one on my last CNC router but haven’t set it up on the MPCNC yet.

@Leo69 Yes I have a touchplate set up on mine. Pics of it here: I was thinking the proximity sensor might be nice for laser height (though our gages are plenty easy to use) or 3D printing. I might add one when I get around to adding an extruder head.