Phaetus TaiChi - Dual color hotend Slicer/Klipper info (Patreon)

ApolloLander and Apollo mini also now supports it ( recommended over the Saturn and titan )

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Some tweaked values: (JUL 2022)

Thanks to KStank (aka Kris Stankievech),
Not tested by myself, but I trust his findings.

MMU Tool change String reduction

• Skinnny dip enabled
• Insertion Distance: 20mm
• Speed into Melt Zone: 15
• Speed to extract from melt zone: 40

Toolchange parameters

• loading speed to start: 3
• loading speed: 18
• unloading at start: 25
• unloading speed: 80
• Cooling moves: 2-3
• Speed of 1st: 20
• Speed of last: 10

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These are are my current findings and slicer settings for the TaiChi. And setup for Klipper.

These can still be tweaked but should be a good start.

Settings - Prusa/Super Slicer

- Cooling tube position: 26.5mm

- Cooling Tube length: 5mm

- FIlament Parking position: 45mm

- Extra loading distance: -2mm (that was a default setting)

Purge volume 40mm3 (about 16mm worth of 1.75 filament) should be a good average maximum ( with some exceptions I'm sure, but a safe starting point )

32mm3 ( about 13mm ) worked as well, but with chances of light color mixing and 24mm3 ( about 10mm ) had some mixing, but nothing too extreme, I wouldn't go below that.

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in Prusa/Super Slicer, under the Filament Settings tab

Toolchange parameters with single extruder MM printers
the speed shown are extruder speed, and you klipper max_extrude_only_velocity will take priority if those slicer setting are higher. So if you extruder can only handle 60mm/s and you limited your klipper config as such, going above those speed in the slicer will not change anything.

The pursa config .ini file attached here has stock values, which should be good, but here are alternative values to play with.

• Unloading speed at the start: 100mm/s
• Unloading speed: 90mm/2
• Number of cooling moves:  4
• Speed of the first cooling move: 20
• Speed of the last cooling move: 10

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Cura didn't work for me as it would need extensive modding to get it to work, as a wipe tower is not integrated in the base feature of Cura, two extruder one hotend isn't either, and loading/unloading has to be done manually through gcode. I'm sure it can be achieved if you really want cura to work, but not worth it for me as of the time of this writing Prusa/Super Slicer are simply better slicer overall.

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KLIPPER  
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Latest version of klipper (early 2022) decided to soon remove shared_heater config option which changed everything. So rather than wait here is the new setup for 2 in 1 hotend

In your printer.cfg update or add the following inside the [extruder] section

everything else here remains the same from a normal single color hotend setup

[extruder]

...

max extrude cross section: 50.0

max extrude only distance: 150.0

...

Then to make it easy rather than add more to the printer.cfg, we'll link/incude a second config file called dual_color.cfgwith only an [include ... ] line in printer.cfg as shown below. (you can rename it to anything you want, just match the filename and the include line to be the same )

[include dual_color.cfg]

Inside dual_color.cfg you will need to update the [extruder_stepper ... ] and [tmc2209 ... ] content to match your board pin names (DO NO USE dual_color.cfg WITHOUT EDITING IT FIRST)

(as of this writing March 2, 2022) Pressure Advance from the first extruder doesn't carry to the second extruder and pressure advance values can't be added to the [extruder_stepper ... ] block

So instead my work around is to run gcode at klipper startup applying pressure advance to the second extruder. Inside the [delayed_gcode...] at the top of the  dual_color.cfg

Change the pressure advance value as those are different with different setup.

[delayed_gcode apply_pressure_advance_setting_to_second_extruder]

initial_duration: 1

gcode:

SET_PRESSURE_ADVANCE EXTRUDER=second_color ADVANCE=0.056 SMOOTH_TIME=0.03

All the other macro in that file are here to handle marlin flavor gcode correctly

In your Klipper interface to control one or the other extruder, click on the T0 and T1 button to control one of the other.

And added a couple macro to load or park filament, copied from generated gcode used in a print. ( as long as you have the correct max_extrude_only_velocity for your extruder, they should work on any extruder, klipper will take the limit in your config into account)

For a dual color print, you want both filament to be in parked position (so away from the nozzle and above the filament path intersection). If printing a single color you want that filament to be loaded and as close to the nozzle as possible.