@Geoff

It sure looks simple but it is much more difficult than it looks People have been trying this method of multi-filament 3D printing for a long time but nobody has got it working reliably...except us! The details of how we got it working are outlined on the campaign page.

@curious aardvark

All technologies that use a single nozzle for multiple filaments require a purge tower. It is necessary to get clean transitions by purging the remaining previous plastic from the hot end. Even dual nozzle solutions require a bit of purging because the molten plastic slowly drips out of one nozzle (and creates messy lines all over your print!) while the other nozzle is printing. In order to reestablish hot end pressure, you need to purge a bit of filament.

Our solution eliminates all of the other issues associated with conventional solutions and essentially lets you print multiple filaments with the precision and performance of a single hot end! The results speak for themselves