I'm thinking of building a new printer and would love to be able to make 2 color prints or dissolvable supports. Does anyone have any experience with this. I see 3 paths.
Two hot ends
Pros:
Most robust
No retraction or filament waste
Cons:
Alignment issues.
Reduced travel
Dragging nozzle
Dual filament hot end(taichi style)
Pros:
Easy to mount
No offsets
Cons:
Jamming?
Long retraction
Y splitter
Pros: easy to mount
No offset
Compatible with any hot end
Cons jamming
Super long retraction
1 (Two hotends): Can be difficult to setup. Requires raising/lowering and ooze shield to lift and block the nozzle. Very reliable and no purging. My recommendation.
2 (dual filament hot end): Easier than option 3 but getting it reliable might be challenging and adds the constrain of filament cooking (requires extrusion of both frequently during the print or the filament/hotend will be damaged)
3 (y splitter): Requires a high-quality y-splitter and perfect setup. Very difficult to nail it reliably. Not recommended if it can be avoided.
more options:
ERCF/MMU/AMS: Overkill for 2 materials and purge block required. Setup is as bad as two hotends.
Toolchanger: Overkill for this. There are applications where they shine but for this general task they are expensive overkill.
Mosaic pallet. Interesting option but expensive. No printer modification required.
2 is mixing hotends. What you describe is 3 (y-splitter with the splitting integrated into the heat sink). They suffer basically the same issues like an "external" y-splitter. You can get them to work but changing materials requires you to do all of the painful setup/calibration once more.
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That they don't have oozing issues is correct but I never mentioned this in the first place.
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The main issue with 2 (mixing) is cooking the filament and slicers aren't great at this (operational challenge). There are more pro and cons but I think in the end it boils down to two applications: 1. cheap to integrate. 2. While they are advertised as mixing hotend the result is on pair with dual color/extrusion filament.