Simultaneous E1 and E0 printing Marlin

Hi all,

My first post in the forum, so thanks in advance for any feedback.

I've been experimenting with a mechanically fed auger print head for printing clay. One stepper controls the auger, which allows for stop/start and retraction. This is E0.

This auger needs to fed material. This is possible with air pressure, however I'm keen to develop a mechanical system to feed the clay to the auger, to avoid hauling a bulky air compressor about.

I have built a simple stepper powered plunger/screw system to feed the clay via a tube to the auger. This is E1.

I need to specify 2 extruders (as E1 and E0 need different steps, as each feed mechanism requires different speeds) but have each run simultaneously on the same E feed from the g-code. I thought this would be simple-ish but am having trouble!

So far, I've used the MarlinX2 firmware (https://github.com/dob71/MarlinX2) as I originally thought the 'follow-me' function would be perfect - two extruders are defined and print simultaneously the same object. However, instead it echoes exactly the E0 signal, so both run at the same speed, which is problematic.

Is there a way to have the firmware set up with 2 extruders (E0 with Xsteps and E1 with Ysteps) but simply send the E-feed from the g-code to both simultaneously. I have been playing around in the stepper.cpp, adding an additional E1 write wherever there is an instance of WRITE(E0 etc. however so far no success.

Many thanks!
Charlie

Edited 1 time(s). Last edit at 01/17/2016 01:19PM by 3dprinting01.

Hi,
My APrinter firmware supports exactly what you describe. But which microcontroller/board do you use? I support a lot of boards, though if you use ATMEGA2560/ArduinoMega/RAMPS, you will have to strip down the features to get it to fit into the very limited RAM.

No way to do that in marlin (that i'm aware of)

But Repetier firmware supports color mixing (ie concurrent simultaneous extrusion)

See this thread on how to implement it [forums.reprap.org]

There is also a version of teacup that is for 5 axis. (branch uvxy i believe) I've not looked into this..

Edited 3 time(s). Last edit at 01/26/2016 02:42AM by Dust.

I tried to do the same thing, (delta printer, with 2 motors working simultaneously, one for main extruder , the other one to supply for clay/concrete or another similar material)

I tried with delta Marlin x2 firmware, with 2 extruders configuration, and dual-X-drive, but didn't work correctly.

Now, I will try the APrinter firmware.

Hello, i`m trying to do the same.

Did you find the Firmware configuration?

Thanks

There is no setting for this...

However Marlin now does support mixing extruders
[marlinfw.org]
I think it can be tricked to always activate a second stepper

So #define MIXING_EXTRUDER
also #define DIRECT_MIXING_IN_G1
you can then set the mixing factors [marlinfw.org]
ie M165 A1 B1

this would normally be an illegal operation as the factors should add to 1, and would be normalized to A0.5 B0.5, but you can disable the normalization

line 3519 of Marlin_main.cpp is
normalize_mix();

you need to comment the line out, ie change it to
//normalize_mix();

also line 12234 is normalize_mix(); also change that to //normalize_mix();

NB This is just a hack, it should work, but I haven't tried it.

Edited 2 time(s). Last edit at 10/28/2019 12:51AM by Dust.