I would like to share a lever action dual extrusion solution I came up with for Ultimaker 2+.
The approach is based on the great effort everyone put into Mark2 and Ultimaker 3.
The print head holds two hot ends, which are originally to be installed on standard UM2 head for 1.75 filament. The right nozzle move up and down for nozzle swapping.
This compact dual print head can achieve single extrusion print area of 220x223x205, and dual extrusion print area of
It may be possible if there is a ptfe tube with 4mm OD and 3mm ID. by looking at the parts i got now, you can maybe get away with drilling 3mm hole in the part with "push" fitting on top. it's only 2mm for 1.75 filament. the "pipe" part and all the way down to nozzle is 4mm to be used with ptfe tube. but i don't think it will be any good without the "4od-3id" ptfe tube, as soon as 3mm(2.85) filament gets down to the nozzle it will melt and creep up the heatsink and pipe because of all the spare