How to multi color print on single extruder ( Ender 3 + Cura )

thingiverse

I wrote this tutorial to share my experience about how to easily make multicolor prints with a single extruder ( ender 3 ) with the highest possible quality by manually changing the filament. The keyring exaples on the pics are made in TPU following this procedure. I've uploaded a simple cube useful to test and get familiar with the procedure: - Load your file in Cura and then click on Extensions->Post processing->Modify g-code - Add Pause at height script (first pic on gallery) - Set Pause at Layer no. at the layer you want to start the new color (the print will pause before making that layer) - Set Park printer head X and Y at 10 to get the nozzle stopped in a convenient position to clear it from color purging. (do not set it to 0 because after resuming it will lose the bed calibration) - Set retraction to 0 (this is a feature useful only for pausing prints because after resuming right before starting the new layer it will extract the same lenght retracted and it's not possible to insert the new filament at the exactly same position of the previous one) - Leave "Extrude amount" and "redo layers" at 0 - Set standby temperature at the same temperature of the print (it's important to set because you will not get over extrusion right before starting the new layer caused by the nozzle heating up) Start your print and wait for the pause - Wait for approx 2 minutes for the extruder stepper being disabled then retract all the filament paying attention to not move the extruder/bed or the z axis height position. (I suggest to use an extruder knob to unload/insert the filament for this critical procedure, I'm using this https://www.thingiverse.com/thing:3373315) - Insert the new color and purge the nozzle until you can clearly see the new color - Leave untouched for a couple of minutes to let all the over extruded filament drain from the nozzle - Clear the nozzle and press the printer button to resume the print with the new filament Pay attention that the script will be saved into Cura for all the files you will open. When you don't need it I suggest to set the layer to a greater value ex. 9999999 in order to disable the script instead of just deleting it. When you will need it again just click on the tools icon that will appear on the left of the Cura slice button and set your desired layer to activate it. Hope that will help ;)