I was aware of the machine’s Kickstarter roots. I was also aware of its entry-level price. Allow me to make something clear. This is not an average entry-level printer or something that required crowdfunding to launch. It is made by Tiertime, China’s first 3D printer manufacturer, creators of the industrial Inspire line and the UP prosumer brand. But really, even with decades of engineering and manufacturing experience behind the Cetus, starting at $299, how good could it be?
I personally bought one for myself after I sent the test machine back to Octave. That’s how good it is. For the money, it was irresistible. The model I tested was the extended version, but I purchased the standard version because I rarely need to print something particularly tall. More on standard versus extended later.
Maker’s Muse reviewed the Cetus on Youtube, but Angus was using a pre-production model. The test machine I received was an improved, full production release.
The Cetus is an open-air, cantilever design with a minimalist appearance. Its frame is made from hardy aluminum extrusions so it is light but strong and the engineering is solid. Linear rails are used, making it quieter than most open-air machines and enhancing stability.
This printer is clearly an UP in disguise, but it is also different, in positive ways. It comes with a specialized version of the UP software, UP Studio, but it is also the first Tiertime printer to accept G-code. Meaning, if you are an UP fan and love UP Studio, you can use the Cetus version of it. If you are a Cura or Simplify3D expert, you can use one of them instead. This is a feature I believe should be in all UP printers. I really like UP Studio for its simplicity and ease-of-use, but those experienced with other brands don’t judge software based on the same standards. For most users, the best software is the software they already know how to use, because they don’t have to learn anything new.
There are a number of other things I have never seen on another UP machine, including a couple ideas I haven’t seen in any other FFF/FDM design. It made me wonder if the printer was partially intended as an experimentation facility, so I called Jason Wu, Cetus Product Manager, and asked him about it.
“Absolutely,” said Wu. “Allen Guo personally designed the Cetus to be both a quality, minimalized printer without expensive bells and whistles, but also to serve as a rapid release method of new engineering ideas.”
For those who don’t know, Dr. Allen Guo is the General Manager and co-founder of Tiertime.
Let’s start with the print bed. Unlike UP printers, you don’t lay an additional print surface on the build platform. Instead, you print directly to the platform, which comes with a coating of gel-like, sticky substance and it works amazingly well. You don’t have to treat the bed with tape, slurry, glue or BuildTak. I never had a print job shift during printing, even though prints were easy to remove from the bed.
The coated bed is not a smooth surface. It creates small contours in the bottom of the printed model, so if you want to print without a raft, it’s a good idea to grab an optional uncoated build plate from Cetus. However, I would print with a raft if you are using the Cetus software. Like UP printers, the raft compensates for the bed not being perfectly level through software-assisted calibration, so it’s just easier to print with a raft.
The platform does not move on the Z-axis. It only moves on the Y-axis. The print head moves on the X and the X-arm moves on the Z. This is another departure from UP.
The bulk of the hot end and nozzle are combined into one part. Not having to screw a nozzle into the hot end means you never need to worry about doing it wrong and causing melted plastic to build up in the filament path, leading to jams.
The nozzle portion itself has a feature I hadn’t seen before and when I saw it, I wondered why it isn’t on other printers because it seems so logical. It is encased in PEEK, which serves a purpose. Right before an FDM machine starts printing, its nozzle pre-drools plastic. It is just above the melting point, so the plastic cools and hardens very quickly. As the nozzle gets closer to the bed, there is a chance the hardened pre-drool will curl up, making contact with the side of the nozzle and melting onto it. If you walked away from the printer before the first layer was printed, you’ll come back to a blob of spaghetti plastered all over the nozzle. The plastic isn’t just melted in place, it is burned black. This usually means trying to clean the nozzle with a blow torch, but the black stain is often permanent. The PEEK on the Cetus nozzle prevents this, unless you failed to calibrate the bed and nozzle height properly.
During testing, I saw this exact scenario play out on more than one occasion. If it weren’t for the PEEK, I would have had to stop the print job before it started or reach under the nozzle to grab the hardened pre-drool, which is a little dangerous. I became comfortable setting up print jobs and walking away, which isn’t something I can say about every printer I’ve operated.
The Cetus I tested had one drawback. If the unit lost power, the print head would drop to the bed like dead weight. Cetus offers a downloadable, printable part called a Z-holder Friction Cup to solve the issue. Installation instructions can be found here. The part can also be purchased for $0.99 on the Cetus site. The just-released MKII Cetus comes with the part, among other minor improvements.
It is primarily intended as a PLA printer. I tested it with Octave’s Precision PLA (a high-quality filament) and some orange PLA of unknown origin. It was several years old and the label had degraded to the point I couldn’t read it, but I think it may have come with a printer I backed on Kickstarter in 2013.
A heated-bed upgrade can be purchased from the Cetus site, which might be useful for certain PLA composites requiring a slightly warmed bed or for printing small ABS parts. However, I am of the opinion that ABS printing should be done with an enclosed 3D printer to avoid warping. If I want warp-free, odorless ABS printing, I’ll use an UP mini 2, which is another Tiertime printer. That being said, I use PLA more than ABS and the Cetus has a larger build envelope, which is why I bought one for myself.
There are two versions of the Cetus. The standard version has a build volume of 180 x 180 x 170 mm (7" x 7" x 6.7"). The extended version is taller, with a build volume of 180 x 180 x 280 mm (7" x 7" x 11"). At this time, only the standard is available as an MKII. The extended won’t be available as an MKII for a while yet.
While writing this review, Octave didn’t carry the Cetus, but they do now. It costs more at Octave, but for US buyers, shipping is free and it comes with a six-month parts and labor warranty, extendable to 12 months.
The Cetus is a genuinely terrific value. It has multiple nozzle diameter options, plus WiFi and USB connectivity. Its software runs on Windows or Mac and there is an app for iPhones and iPads. Thanks to its ability to use UP software, I would recommend it for beginners, but I also recommend it for serious enthusiasts. It is the most modifiable and open source-compatible Tiertime printer to date.