One thing I see with a Kickstart comment forum. It helps clear the ignorance of the new product. Some of the folks asking concerning (worry) questions need assurance they have invested in a good product. It’s human nature.

The more experience folks (myself 5+ years) who understand the FDM 3D printer hardware design and especially the FDM single nozzle printing process, have great success doing it.  We ask few questions of concern. 

The Cetus2 is going to be a good dual filament single nozzle printer. It really does have the right stuff. The only component that is truly experimental is the new nozzle design - shown in the lead picture

I have explained on the forum that mixing DOES NOT occur within the nozzle. It is an external process. It’s clearly apparent and confirmed by Jason Wu, forum moderator. So it works the same as all other single nozzle mixing designs. 

What I like is  that its new design keeps colors (filaments) separated as long as possible within the nozzle. This greatly reduces the purge amount when doing a 100% feed change.

I decided I am willing to wait for the final design. I can see the print results in the material examples in the photos and videos. They appear excellent which of course should be expected with “product display” examples.

Nozzle fouling has not been an issue in my FDM printing experience. I usually run one nozzle for many months of constant printing and use many type of <150 deg. filaments without clogs or need to change. I usually wear the ends down, making the tip wider. My method: Never leave a nozzle set at full temp without filament flow.

I am not going to speculate about the new Cetus2 nozzle. It’s not in final design. However Jason has stated the development nozzle is welded on and fowling has never been an issue. The release version will have a replaceable nozzle.

Multi-filament single nozzle printing is certainly not for everyone and every possible need. Good operation and expectations require understanding design limitations and capabilities and a certain amount of operator discipline (operation knowledge).

I my opinion, color change and  blending of same base filament type are the Cetus2 strong points.

Mixing base material (type) is certainly getting into the experimental printing. A good area to explore but this is not typical with single nozzle printers. Cetus says they have accomplished this.

My advice: Order a Cetus2 if you wish to explore color mixing and blending. (I love the color effects achieved.) Cetus2 will read gcode and work directly with 3rd party slicers. UPStudio will offer additional capabilities and an OctoPrint type network server is in the works.

Mixed filament types are an area for me to explore. I expect results will vary with user understanding and abilities. Tiertime says the hardware design is intended for this application. I strongly suspect operator finesse will be a factor. 

I  have posted a request on the Kickstart forum on Cetus2 about filament management and individual (if possible) temperature control. Not a worry, just informational. <grin>  It looks like the barrel type devices on each filament side may be individule heaters... So I have inquired about temp control.