Presenting my first gradient vase, printed on a Geeetech A20M

Here it is. My first color mix print! How does this work? Well, it is a feature of the Geeetech A20M (and also of the A10M and A30M) which has a 2-into-1 or "Y" nozzle and 2 extruder motors feeding it.

Via the standard firmware, Geeetech's fork of Marlin, you can:

• switch between two spools of filament
• set a color mix ratio, say 30% of spool 1, 70% of spool 2
• define a changing color mix aka a gradient.

You can do this at any given time, even when you're in the middle of a print.

This vase was sliced normally, so the gcode has no instructions for dealing with multiple extruders, and the the gradient was configured before the start. From 100% purple & 0% pink to 0% purple & 100% pink. And this'll give you a print that starts purple at the bottom and ends up pink at the top. Color printing but without a wipe tower ;-)

purple/pink gradient vase

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Current mix ratio: 100% purple, 0% pink

You can even go further and define multiple color changes and/or gradients ahead of time by pre-processing the gcode file. For this Geeetech offers an application called ColorMixer, which runs on both Windows and MacOs. (To be honest, post-processing gcode isn't the most elegant solution and for Cura I hear there is a plugin to do it)

https://i.redd.it/eklvlf0jnr631.png

In general, printing in different colors using a single nozzle is limited by the time and extrusion length it takes to change from one color to the other. By applying a gradient vertically you all but guarantee that the desired color mix ratio changes slower than it takes to purge the melting chamber and therefore you don't need a wipe tower in this case.

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Dual color printing in the normal sense, where color changes are discrete, are still possible by using a wipe tower of course (this'll be my next project).

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So to conclude, I'm super excited with the capabilities of my new new printer. Have any of you done any color mixing? With what kind of printer? Please share your results & ideas! :D