Another multi filament hot end

I was intrigued by uGens entry under 2 Extruders : 1 Hotend but didn't want to muddy that area with something that is a bit different.

Some months ago I thought of this idea for a single hot end with several nozzles. The bit that I haven't seen before is having the nozzles spring loaded - yet free to move in the heater block. The idea is that when a filament is fed, for the first distance, say 1mm for example, all that happens is that the nozzle moves forward until it reaches a stop, then the filament starts extruding from the nozzle. When it is time to switch to another nozzle, the one filament in the one in use woule be retracted normally and the nozzle , assisted by the spring, would return to it's up position.


Multinozzle showing blue filament head extended, others in rest position.

There are a number of problems with this, none unsurmountable. The filaments would have to work in the same temperature regime, Nozzles and heater blocks would need to be made of something that doesn't oxidise or do anything else to inhibit free sliding etc. Obviously the shown coil springs couldn't be used as they would soften at 230 degrees (would work for extruding chocolate though)

I have several other things that I am persuing at the moment and don't think that I can persue this in the near future - so it is in the wild for anybody who wants it.

Mike

What about oozing? Where is the motor/hobbed bolt?

As long as the moving part of the hot end conforms to the usual all metal thermal profile there should be no oozing. Whether there needs to be cooling, and if it is better to provide this by for example, water cooling, or cool blocks I leave to anybody who thinks the idea has merit. As to the hobbed bolt etc., I have left this out for simplicity -along with the rest of the printer.
Mike.

Just throwing a thought out there to try and over come the single temp hot ends.



You can probably have one heatsink for all three ends with a fan mounted on it.

Great idea! What if you use this extruder?
[www.thingiverse.com]
2 motors and 3 filaments. I was thinking a bit about how to make it easier to print and fit more filaments but nothing concrete. Let us know how you fair, I'm very excited!