It seems too good to be true, and it may be. German maker Andreas Haeuser, of RepRap Turbine, has posted a set of plans and design files (for sale) for a printable robotic lawnmower that uses almost exclusively 3D printed parts (which can be printed on any printer with a minimum build volume of 180mm x 180mm x 60mm) and an Arduino Uno and motor shield for its brain.
The 3D printed Ardumower works on the same principle as its commercial counterparts, which can be bought for a lot of money at most hardware stores. It drives in the inner space of a “boundary wire fence” (BWF). If it comes close to this it stops, turns, and then it goes on mowing your lawn continuously. The Ardumower is well-tested for a lawn size up to 500m². If your lawn is bigger, you need a second battery or you should print a second Ardumower.
The Ardumower is driven by two 12V geared motors. The cutting device is made from a 12V DC-motor and a cutter disc with a diameter of 220mm. The power comes from rechargeable 12V NiMH or 11,1V LiPo batteries.
Andreas claims the mower works well, has been thoroughly tested, and is a really fun project to print and assemble. I have my doubts about the battery life (among other things), but I love the very 21st century solution to that problem: “…print a second Ardumower.” In the end, I have a feeling this is more of an exciting proof of concept and a fun weekend printing and programming project than a mower you’re going to press into service every time the grass gets tall. The construction manual and print files are available for download for US$12.39. His site also features downloadable plans for a 3D printable wind turbine and a solar-powered Stirling engine.