Robotic vacuum cleaners have become commonplace over the last few years, or at least common enough that no one is surprised to see one resting in the corner of your house. Robotic lawnmowers, though, are seldom to be found roaming suburban neighborhoods, perhaps due to safety concerns, cost, or simply the fact that a lawn doesn’t guarantee a smooth surface.
Philip Read (AKA ReP_AL) is doing his part to change this situation, however, with a very nicely designed mower that can be 95% 3D printed. You’ll need a fairly large print area (330x330x400mm) to build the body, though mechanical components are available for sale if you’d rather go that route.
Electronics-wise, the Roomba-like device features a full three Arduino boards. At the heart of mower lies a Mega, which handles steering via twin gearmotors and the motor that turns the blade itself. Perimeter wire sensors are used for navigation, and a trio of ultrasonic sensors are implemented for object detection.
A Nano measures battery voltage and passes this info on the the Mega, allowing the robot to limp back to its charging station for a refresh when needed. As shown in the second video below, the charging station is quite a nice project itself, resembling something between a dog house and a mailbox. Finally, an Uno is used to control the perimeter wire that keeps the robot traveling in the proper area.