A dual extruder that uses a single stepper motor

nowhere have I found the settings for my printhead that it uses: V-extruder MFG V7 - DONDOLO rework by DrumClock - Thingiverse

Two hotends and one extruder motor that changes the direction of rotation according to
the tool used (T0 / T1).

In Marlin , this provided the #define SWITCHING_EXTRUDER setting.

Is there any way to do this in Klipper?

Unfortunately, it’s not currently supported. It’s been discussed before (eg, Shared motor for extruders · Issue #2171 · KevinOConnor/klipper · GitHub ), but I don’t know of anyone currently working on it.


Thank you for responding to my question. It is a great pity that the stepper motors are “tied” to the Hotend (extruder). Using one stepper motor for two HotEnds is an advantageous thing.
I wanted to revive my printer with 4 extruders (4 Extruder on IDEX by DrumClock - Thingiverse) on Klipper, because on Marlin it works but only with G-code modification using Postscript which partially takes over control but SWITCHING ETRUDER function is necessary which is not in Klipper right now … a pity. It’s faster and more economical than the MMU2 version.
I hope someone takes over and moves Klipper another level ahead of Marlin.


With the great help of the user “Alexz” we are testing the configuration for SWITCHING_EXTRUDER.
So far so good …


So I tried it all and it’s okay.
Is it possible to add it as an example to Klipper?

sample-switching_extruder.cfg (7.0 KB)

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Since this essentially fixes the main issue of rotating the extruder motor the other way depending on the tool chosen, with some settings tweaks it should be able to work with this setup?
[Bowden dual/quad extrusion extruder (single-nozzle single-drive) ]
(Bowden dual/quad extrusion extruder (single-nozzle single-drive) + video by FDMTech - Thingiverse) Not looking to go quad multicolor just yet, mainly to use PVA for supports. If not then I will look into the switching setup you have.
Regardless of the answer I have to congratulate you on sticking with this and finding a solution cause it seemed most threads I found ended up being no responses, dead ends or getting closed since so much time would pass.

here is an improved version of the configuration … download what you need for your printer …

switching_extruder (1).cfg (8.5 KB)

and addition of the endless spool function …

endless_spool (1).cfg (8.6 KB)

Hi can you maybe help me with my setup? It’s also a dondolo but with mechanical switching. Video: (Uprint Extruder - Album on Imgur)

What exactly do you need help with?

Just want to know what in the switching_extruder config can I remove so that I get the same result when using the mechanical dondolo.

I have completely redone the macro and have tested it. Switching is in [gcode_macro SET_HOTEND]
The macro is for the 4EX2 printer, but it should also work for one carriage and 2 hotends.

SET_HOTEND.cfg (5.6 KB)

I don’t speak English and I use a translator, so I hope I understood you well.