Open Letter to Tiertime Cetus2
As everyone can see on this blog, I am an actual user of an early prototype of the Cetus2 dual filament single nozzle 3D printer. I am simply lucky and grateful to have an opportunity to show it to readers of this blog.
I do NOT represent Tiertime and the Cetus2 (and UPStudio3 (UPS3)) teams in any official way, shape, or form. I simply show what I can make with the Cetus2 I won in a New Year’s Resolution writing competition.
I do not have two machines (yet) but I am a KickStarter investor the same as everyone else on the KS forum. I hope to have two in the future...
My current opinions on Cetus2 prototype
The hardware is mechanically all the "right stuff". Linear rails and extremely heavy dual Z axis linear bearing columns. Rigid construction throughout. This is why I joined the KickStarter.
My original prototype (non-replaceable nozzle) printhead was updated to the replaceable nozzle version, gratis by Cetus.
The direct feed extruders and extremely short filament mix-to-nozzle discharge point makes for the quickest filament change of all the single nozzle multi-feed print heads of which I have experience and knowledge.
This "short filament path" is the reason for the "On The Fly" (OTF) color changes, emphasized in the Cetus2 marketing. Although OTF is possible, I personally do not think it should be the main reason for purchase.
In my opinion, the Cetus2 is currently the "best of class" for extruder and hardware design for single nozzle 2 color FDM printers.
The dominant weak point with Cetus2
Again, my opinion. - a weakness is the Tiertime policy of totally controlling all Cetus2 software options. I believe the UPS3 software is now one of the big reasons for the Cetus2 production delay, along with the COVID and build material supply chain deficiencies.
I have used this slicer since the early “catfish” version. Catfish was an attempt to give power users more control over their prints than the limited variable options provided in the standard UP Studio. But with more variables there becomes more support issues from the few owners who should not be playing with variables not fully documented, explained in detail, and fully understood,
Some of the basic functions, like easily removeable supports and nozzle hop, are broken in the current UPS3 V 3.2.5. There have been no updates for months. I just recently tried to download the WIN version, but it delivers the Apple version. The Tiertime forums have been moved around and are in shambles. I believe Cetus2 and UPS3 development must be in a state of chaos or deadline panic.
I am a power user. I want Cetus2 to be fully operational and compatible with Marlin 3D print g-code as published. Not just selected portions of it. Not EVERY g-code, but those appropriate for the Cetus2. It’s been promised that Cetus2 will work with other slicers for everything except special editing features in UPS3. This is a must happen as it has been prominently advertised as a selling feature. But there is now an an unsubstantiated rumor confirmation on Kickstarter that the “open” Cetus2 may be is canceled.
With my other single nozzle multi filament printers, using Marlin g-code, I have been able to configure up to 6 nozzles (two real and four phantom) and have six color mixes available in a single print. Here is the evidence in this PHOTO. If UPS3 can't or won't do this, I need to use another slicer.
Not for Everyone
The Cetus2 is a specialty printer. It extrudes two filaments out of one nozzle. Side by side if the mix is 50/50. Printing with two or more colors and mixing for color effects is MY PRIME reason for use of the Cetus2.
There is no doubt some mixes of two different types of filament materials can be extruded alternately from the single nozzle with proper purging. Tiertime Cetus2 shows it being done. However, in my opinion, this is not the best application for a single nozzle printer. There will always be a bit of cross contamination.
My choice for printing two differing materials is an IDEX (independent dual extruder) printer. Second choice is a standard tandem dual extruder. Last choice is Cetus2, single nozzle. You are not required to like what I just wrote.
Same thought for exotic high abrasive and high temperature filaments. Who (not I) wants or needs to swap these filaments within a single nozzle? They are not made in a wide color selection for mixing and support material is generally printed at a much lower temperature.
One last point is using any single nozzle multi filament printer to just print one color. I recommend using two spools of the same color and mixing 50/50. I cover this HERE.
My Conclusions
Cetus2 is a good hardware design. The hardware re-design shown in KickStarter was a big error. The conclusion from most supporters was it certainly looked to be due to cost reduction efforts. The quick reversion brought back the original style.
I have no desire or need to be a fan-boy for Tiertime or Cetus. Just a bit of obligation to share my good fortune for receiving a prototype with some show and tell.
When all the software and other issues are fixed, I expect my experience with Cetus2 to exceed my expectations. For now, I can produce excellent prints within the boundaries of a less than perfect early prototype machine and software.