M600 like custom change filament solution question

Hi all, a question related to Marlin Firmware and the M600 change filament command.

the change filament M600 works, but I need a slightly different set of commands to run a filament change.
I have tried to do this with a custom menu item and a couple of ' enquecommand ' lines to perform the necessary steps
Unfortunately it doesn't work all the way. Maybe you can provide me a solution... (not a start an C+ coding)

This is what I need:

when a filament change is needed:

- I press a menu Item (change filament)
- extruder moves up 5mm
- extruders moves to X3 Y3
- NO rewind in filament here!!
- wait with beeping sound

(here I change the filament cartridge, when done I press the 'finish change filament ' menu option)

- First the extruder needs to extrude an amount (E+1000) of filament at it's current position.(X3 Y3)
- move back to the original print point
- reset to the original E value (E-1000 at this point) WITHOUT the extruder motor actually moving or turning backwards
- move down 5mm
- continue printing.


My issue is with the Rewinding of filament. Whatever I try, I can't reset the E value after E+1000 extrusion to the Original Value from when I press for a change filament.
So It will either rewind before the E+1000 command (normal M600, I don't want that) or it will rewind after the E+1000 command to get back to its original E value where it stopped printing for filament change!

Using Marlin and Arduino + Ramps,
Any solutions?

Edited 1 time(s). Last edit at 04/01/2017 06:05AM by DesignSmurf.

You could slice your models using relative extruder coordinates instead of absolute.

Edited 1 time(s). Last edit at 04/01/2017 06:13AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Hi Dc42

I was thinking about that, but how to move to X3 Y3 from a relative position during the print. And return back to the initial position after the filament change?

Quote
DesignSmurf
Hi Dc42

I was thinking about that, but how to move to X3 Y3 from a relative position during the print. And return back to the initial position after the filament change?

I don't know how to do that using Marlin, but it's easy with RepRapFirmware. You use M83 to make extrusion relative while keeping XYZ movement absolute. Then you execute a pause to move the head to wherever you want. When you are done you use G1 R1 to move back to the paused position. Perhaps Marlin has something similar.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I got it working slicing with relative E...
Not a very nice option but it's okay.
Unfortunately Slic3r has a Bug using Relative E and spiral vase, it produces a weird seam.

Thank you very much!

I am still looking into finding a way to use a Variable as an Gcode value as this would give me much more freedom to finetune the material change.

Quote
DesignSmurf
Unfortunately Slic3r has a Bug using Relative E and spiral vase, it produces a weird seam.

It worked OK last time I tried it, but that was a long time ago. Which version of slic3r are you using?

Edited 1 time(s). Last edit at 04/02/2017 11:23AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

1.2.9
but the bug has been in there for some time.
prints good without spiral.
and the custom change filament also works now.
just not with a spiral vase code!

** SOLVED **

This is done with the latest Marlin instalment, RC8.
In the Next release it will be part of Marlin.

Edited 1 time(s). Last edit at 04/07/2017 03:27AM by DesignSmurf.