Best touch plate solution to date?

I’m about to pull the MiniRambo off the drop table and replace it with the Rambo and endstop wiring. While I do so I’d like to incorporate a touch plate so I can nail my tool changes finally. If you all saw how I do them currently you’d wonder how I ever got good results…

What’s the best way about this according to the collective here? One of the tall disc and alligator clip things form Amazon? A diy moveable piece like Jeffe’s spatual plan? A piece milled in flush on the work surface and hard wired into the table/board?

I use a magnet and some metal tape…ghetto fab baby. I do have a few super fancy high tech one here that I have not tried out yet…ghetto works so well I never walk up the stairs to get the fancy ones.

The key bit is knowing precisely how thick the touch plate material is, right?

I use a 4" putty knife from Harbor freight. It gives me plenty of room to put the alligator clip on. You can probably find them at dollar store also.

I have to admit I haven’t looked deep enough into it yet in terms of how they are wired up. I assume the cutter contacting the metal closes the circuit to the end stop. So one wire from the board goes to the metal plate, the other wire has an alligator clip that you clip to the cutter? Is it that ‘simple’?

It’s that simple. You are just creating a a NO switch. The Putty knife though is a great idea. Will be using that.

Thanks gang. Then once I know the thickness of the plate I add a start code that alters the z axis by that amount and I’ve got perfect zeroes for the rest of my days?

M851 z-[plate thickness here]


thickness = 0.8, safe level = 40 :
G28 Z
G92 Z0.8
G0 Z40


you also can surround it with M0 commands to waiting with showing hint on the LCD

M0 Attach probe
G28 Z
G92 Z0.8
G0 Z40 F300
M0 Detach probe

Just trying to see if I understand this.

The end stop will trigger at .8 but set the machine’s coordinate (understanding) to 0. By using G92 z0.8 you’re telling the machine that it’s ACTUALLY at 0.8 right ‘now’ and so any following gcode will be reduced by 0.8?

Would M851 Z-0.8 do the same thing? And if so, why use one over the other?


i don’t think so. i guess it dedicated to hint machine how to interpret probe coordinates when you perform bed leveling with G29. I think G29 not useful for CNC application

Aluminum foil means you don’t have to allow for thickness of the touch plate, and you can set it at the top surface of your piece.

Just a couple of alligator clips in that case? One to the foil, one to the cutter?


Imho, foil isn’t best solution. It’s easy to get it creased and you can’t be sure that it lays flatly on the surface. I guess you can’t just hold by one hand or just drop and make homing.

I cut a square of aluminum foil out of the flat bottom of a heavy duty disposable pan, like from Thanksgiving. To make the connection I soldered to a paperclip and slipped it on the foil. So, far working great!

I just use foil tape with a corner folded over and stick it to where i need my 0 and re 0 on tool changes on the face and it never moves :slight_smile:

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I’m using a 6" long .08mm feeler gauge.

Works fantastic!!!