Multi Material development.  I have some overall suggestions about how to get from a

Multi Material development.
I have some overall suggestions about how to get from a multicolored design to a multicolored part.

The current release doesn’t export AMFs. But before it does, we need to have a way to tag solids as a specific material. Maybe a material(name); function that will name a material in the AMF file. That name could be Blue, Support, PVA, ABS, or anything else descriptive.

Slicer can combine STLs into an AMF (thx @ThantiK ) but we need some settings to work with those named materiels that we made in OpenSCAD. Just like how we can choose what extruder has support or infill, we need an option to map a material to an extruder. A setting to record what filament is loaded into what extruder is helpful. This would also need multiple filament tabs.

I’ve only had experience with the 3 extruder BFB3000, and it’s not positive. The problem with most multiextruders is the idle nozzle is on the same plane as the active nozzle. The idle nozzle drools, drags through the layer, or otherwise messes up whatever the active nozzle is laying down. The dual extruder MB solved this a tiny bit by wiping the nozzle after every freaking layer. @Whosa_whatsis how does the bukobot handle messy 2 material prints?
The oldest solution is from the 1980’s stratasys: a solenoid raises or lowers the support side on demand.

Any thoughts?

I’ve got an article on how to do it with slic3r that’s almost ready. The short version is that we cool the idle nozzle to a standby temperature to prevent ooze.

I’ve been considering an approach for this too. Using a dual extruder on a pivot point, where the idle head would pivot up, and even possibly park the nozzle against a metal plate to prevent ooze while in the standby position.

This could be attempted with a bowden setup, 2 steppers opposed from each other for balance, or possibly one stepper where the active extruder’s gear engages the gear on the stepper, while the other’s is disengaged.