Recently, [Thomas Sanladerer] bought an EasyThreed K9 off AliExpress for a mere €72, netting him an FDM printer with a 10 x 10 x 10 cm build volume. The build plate is unheated, with optional upgrade, and there is no display to interact with the device: just a big multi-function ‘play’ button and five smaller buttons that direct the print head to preset locations above the build plate to allow for build plate leveling using the knobs on each corner. There’s also a ‘home’ button on the back for homing the print head, which pretty much completes the user interface. As the printer comes in a rather small box, the first step is to assemble the parts into something resembling a 3D printer.
What follows is both a mixture of wonder and horror, as the plastic build quality is everything but convincing, while at the same time, the self-contained nature of each of the three axes of the cantilevered design makes for very easy assembly. The print head has a nifty flip-up cover for easy access to the hot end, which makes the best of the anemic 24-watt power supply for the entire printer. A cooling fan with an air duct even provides part cooling, making this print head a contender for the ‘cheap but not terrible’ category. You can check out his full video review below.
[Thomas], of course, had to look at the control board. It turns out that it’s not a known controller, although some of the components are familiar, and many expansion options are visible on the PCB, including, potentially, WiFi.
The heart of the controller board is the ARERY AT32F403ARCT7 MCU, which [PeetHobby] in the comments notes is more or less an STM32 clone based on their experiences with the chip. This MCU runs at 240 MHz, with 1 MB flash and 256 kB SRAM, and a feature set and register layout similar to STM32 parts.
After running a few prints on the printer, [Thomas] concludes that although it’s not a terrible printer, the good parts about it are somewhat ruined by the slop in the connections between the axes. There’s also no easy way to use full filament spools with the printer, only the smaller 250-gram ones. Although a ‘no buy’ if you want to get an FDM printer that works out of the box, the amount of hacking potential here is rather large, as evidenced by the many comments about it.
We remember when a cheap printer was around $200. This isn’t the first Easythreed printer we’ve seen, but they do seem to be getting better.
Source : https://hackaday.com/2024/02/12/easythreed-k9-the-value-in-a-e72-aliexpress-fdm-3d-printer/