Resetting X,Y,E with Homing

Looking to replicate a feature on Markforged printer in Marlin and Prusa Slicer.

Markfoged desktop printers do not have any closed loop error correction systems nor any encoders, they use optical end stops.

During print they home it on X,Y every few layers, Stratasys does the same thing. I believe they use Absolute coordinates and do some type of reset to Zero on that homing to eliminate error accumulation.

I know Marlin has some features that will override G-code from slicer. Is there anyone here with enough skill to produce a combo of possibly Script + Gcode for Prusa slicer that will accomplish this scenario:

1) The end user in the slicer script or Gcode can choose after how many layers it will home it and reset the X,Y and E as well. I think it’s G28 command on reset, ot sure if it’s all axis or you can select which ones.

2) Marlin has a baked in feature where it resets the E on each layer change, if it’s in Absolute mode. Is there anyway to remove it via Gcode so it will only reset it on my home reset not on each layer change.

3) Last major issue is retraction, that home X,Y needs a much longer retraction vs. the one to use during print. I know Marlin has some features for two retractions:


[marlinfw.org]

[marlinfw.org]

[projects.ttlexceeded.com]


Prusa Slicer has two options one is MMU, I don’t use prusa printer so that option is not viable, second one is dual extruder where you have two retractions one per each extruder .

Maybe there is a way to trick Prusa Slicer that we have a tool change on each home reset but we do not change the extruder, or trick Marlin into some type of fake tool change so we reset it on X,Y,E with two separate retractions yet no nozzle offset, or park or pause or purge or anything else associated with proper tool change.

I don’t know anything about writing scripts or Gcode, maybe someone is skilled enough to reproduce this solution. I’m willing to pay for this as well.

Cheers

"2) Marlin has a baked in feature where it resets the E on each layer change, if it’s in Absolute mode. Is there anyway to remove it via Gcode so it will only reset it on my home reset not on each layer change."

This does not exist in Marlin, You are mistaken.

E position is set back to 0 every layer via the slicer generated g-code. In particular it uses G92 E0.0

This is the setting in Prusa Slicer
; before_layer_gcode = ;BEFORE_LAYER_CHANGE\nG92 E0.0\n;[layer_z]\n\n

Here is the setting in the GUI



Edited 3 time(s). Last edit at 12/09/2022 07:24PM by Dust.

That's a small issue to fix, what about the main issue?