A new 3D printer has appeared on Kickstarter: the Yumi C series.
Who is Yumi, you ask? They seem to have been around for a while, producing a line of 3D printer filament. They don’t seem to have a website of their own, but appear to sell the filament through others, such as Wanhao.
After two years behind the scenes, they’ve developed a new desktop FFF 3D printer, the C series. It’s a series because it comes in three different models, the C235, C335, and C435.
The main difference between the three is the build volume, which ranges as follows:
- C235: 235 x 235 x 235 mm
- C335: 335 x 335 x 335 mm
- C435: 435 x 435 x 500 mm
Each device is a bedslinger, and they are open-gantry affairs without an enclosure. They do use Klipper firmware and can print at higher speeds. Yumi said the printers can reach 700mm/s, but that is likely only when printing 0.1mm layers.
The main feature of the C series is the multicolor extrusion system, which is somewhat different than the commonly used “AMS” style approaches used by several other key manufacturers.
As you can see in the top image, the C series mounts the spools on top of the machine. The spools sit inside the YMS, “Yumi Material System”, which is an integrated dryer and storage system. Up to twelve of these can be mounted on top of any of the C series devices.
The interesting aspect is that you apparently add them individually. Need only two materials? Just get two YMS units. Need nine colours? Buy nine.
The only catch is that it might be more expensive than the fixed four systems from other companies, since you’re buying one at a time. But is that true? I did some math on their pricing and found that the unit price for the YMS, at least in the Kickstarter campaign, is around US$33-37. That’s pretty cheap compared to any other single spool holder. On the other hand, it seems to be just a plastic enclosure with some rollers.
The filament changing operation is where things differ from other systems. Yumi states that they have to retract filaments only 10cm from the nozzle in order to perform a switch. This is somewhat less than the length required on other systems, so there are time savings there.
The other change is that the filament is cut “close to the nozzle”. Other systems cut the filament well above the hot end, leaving a considerable amount of leftover material in the hot end and nozzle. That material eventually becomes 3D printer poop that is ejected, and therefore wasted.
Yumi’s proposition is that by cutting the filament closer to the nozzle, there is far less poop. I expect there still to be poop on each filament swap to clean the nozzle, but here the amount of material per poop would be lower. That should also speed up the print job somewhat, and drastically reduce the amount of wasted material.
Pricing on the C series seems to be the most important factor, aside from the twelve spools and lower filament usage. The base C235 is listed at a ridiculously low US$195 (with MSRP of US$299 eventually). There are plenty of price variations for different combinations but the highest price listed is for the large C435 with twelve YMS units at US$780. Every other combination is less than that.
According to a look at the backer counts at the time of this writing, it seems that the C335 is the most popular of the three, with many seven-colour units being ordered. Strangely, 95% of the C435 orders are with twelve YMS units. Few are ordering the base units without any YMS units, suggesting that multicolour is a requirement for most people.
In all, about US$360K of equipment has been ordered on this campaign, showing it has some popularity. However, be aware that this appears to be Yumi’s very first 3D printer product, and that most of the new 3D printers on the market are enclosed CoreXY systems.
Via Kickstarter and Yumi Wiki
