Tool Change G-Code

Mostly Printed CNC - MPCNC Advice
1

I have an MPC CNC with SKR Pro Controller.

What g code do i need to use to pause for. tool Change and how to i get it to life to certain coordinates to give me room for the tool change as wel\l as trigger the z prove so i can re zero the Z position for the new tool.

I realize this has been asked in some form before but I read several other topics and was really clear how to achieve my desired outcome.

Thanks

2

Assuming you are using the V1 firmware…

The Primo firmware (as.opposed to the LR firmware) for the SKR Pro uses the touch plate as a normally open end stop switch. As such G28 Z will tell the machine to probe downwards to the end stop and … well stop.

The V1 custom menu should have what you need there, but that’s not accessable from your CAM

On the LowRider, G28 Z will home the machine up to the stop switches, then G38.2 Z0 will probe downwards to the touchplate.

In both cases, a little more code is needed to set the Z=0 point.

G92 Z0.5 ; Change 0.5 to the actual height or thickness of your touch plate, this is for the one sold in the V1 shop.
G0 Z5.5 ; raise the tool 5mm.

If you want to have a place to pause the Gcode

M0 Change Tool

Should work. You can put whatever text you want displayed instead of “Change Tool” there. This assumes that you are using an LCD controller. May not work with cnc.js or Octoprint.

Personally, I have separate files for each tool, so I can be satisfied that I have everything with the new tool set to zero the way that I want it. So I don’t use tool change gcode.

3 Likes
3

Thanks that’s an interesting idea. I think I link that a lot actually. Thanks

I’ll have to play with kiri:moto and see if I can export each tool path separately.

4

If not… just ser up the tool change code something easily searchable and fast to spot when scrolling through a lot of text.

# ******************************
# *
# *
# *
# * Split File Here To Change Tools!
# *
# *
# *
# ******************************

You can even add in actual gcode like the above, then it’s easy enough to cut and paste the individual tool sections together.

1 Like
5

Agree 100% with separating the files for each operation. Plus, changing tools to run another file allows for pee break, grabbing snackage, or if a long operation a stopping point to continue another day. Especially when the garage is 120f…lol

1 Like