Hi, I'm looking for some advice on a highly customized 3D printer setup!

I have a home-made printer using a RUMBA board with Marlin and stepper motors that I control via Printrun's Pronterface using my laptop. It has dual Z-axes configured so that each of my two Z-axes move together (both are plugged into separate ports with their own TMC drivers). I am aware of all the auto-leveling features, but none of them seem to allow me to manually control each axis independently for a brief moment (ie by sending the G1 command). I move them together 95% of the time under a single axis name, "Z", but 5% of the time I'd like to decouple them to move independently. I end up just manually twisting the lead screw with my hand, but it would be nice to be able to control them independently by sending G-code commands. I haven't found a workaround to do this, so any guidance would be greatly appreciated!

... it's possible, but not so easy, to modify Marlin to do what you want - I had to tweak it for different reasons too some years ago.

Essentially you'll have to add some G-codes and change the parser for moving the spezific motors separate -- e.g. something like using "Z", "Z1" and "Z2" in your moving G-codes.

For example: "G1 X[xx] Y[yy] Z[zz] E[ee] F[ff]" will move both axes together - while ".. Z1[zz] .." or ".. Z2[zz] .." will move only the specified one

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

You cannot have axis Z1, Z2 etc this will break things badly

Gcode is space independent

so if you sent a G1Z120 did you mean move Z to 120 or move Z1 to 20, there is no way to tell.

This is also why we don't have E0,E1 etc, but only E with the T gcode to change the tool

Edited 3 time(s). Last edit at 04/26/2024 05:14AM by Dust.

... then maybe "Z", "ZA" and "ZB"? ... while A and B arent used otherwise, the parser could solve it

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Yes, this is exactly what I want to do! Do you have any pointers for what exactly I need to change in the firmware to get started in figuring this out? I am guessing it is not as simple as just overdefining additional axes with different names but overlapping pins. I am using all 6 axes available on my board with none defined as extruders. Each are individually defined in the firmware as X,Y,Z(dual),A,B. Thank you!