In this era of cheap turn-key machines, the idea of actually building your own desktop 3D printer might seem odd to some. But if you’re looking for a challenge, and want to end up with a printer that legitimately sets itself apart from what they’re stocking on Amazon these days, then take a look at the Lemontron.

We’ve been keeping tabs on the development of this open source 3D printer for some time now, and just before Christmas, the files finally were released for anyone who wants to try putting one together themselves. There’s currently no formal kit available, but once you’ve printed out all the parts, there’s a very nice bill of materials you can find on the website which will tell you everything you need to complete the assembly — and critically — where you can get it.

The hotend and heated bed come from KB-3D, while the bulk of the rest of the components are sourced from AliExpress with a bit of DigiKey sprinkled in. There’s also a custom PCB you’ll want to pick up from your favorite board house. All told, building the Lemontron should cost you somewhat north of $400 USD. Of course, that assumes your time is free. But since you’re reading this on Hackaday, it’s probably a safe bet that you’ll enjoy your time.

You can check out the video below for an expedited look at assembling the printer. It’s not a step-by-step guide exactly, but it should give you a good idea of what to expect before you commit to building the thing. It also provides a look at the design philosophy behind the Lemontron, which largely eschews custom components and relies on off-the-shelf bits to tie all the printed parts together.

If you’re wondering were these upside-down 3D printers came from, the Lemontron is ultimately evolved from the Positron that we first covered back in 2021.