Robot mowers are a familiar sight in German gardens. What is less known is that home gardeners can build a robot lawn mower themselves. If you have large lawns to mow, you can use ready-made kits from specialist retailers. Innovators achieve useful results for small green areas with inexpensive components that can be purchased everywhere. This overview will familiarize you with the basic components for DIY construction.
How can you build a robot lawn mower yourself?
To build a lawn mower robot yourself, you need a frame, mowing disc, accumulator, traction motors, drive wheels, a mowing motor, a 3-axis compass and a Raspberry Board Pi. You should lay a cable to limit the mowing field and attach antennas to the robot.
Basic components for a robot lawn mower
Gardeners with the heart of a brilliant software developer have developed a robot lawn mower for the average ornamental garden. The device provides a WLAN access point so that you can use your smartphone for manual control. We summarize the basic components for self-assembly below:
- Frame: Square tubes welded in a triangular shape for 2 drive wheels and 1 front steering wheel
- Mowing plate as a platform for wheels and battery: disc or triangular star of a chainsaw with 3 carpet knives
- Accumulator: car battery with 36Ah
- Travel motors: automotive windshield wiper motors
- Drive wheels: removed from the old petrol lawnmower
- Mowing motor: Radiator fan motor of a VW Passat or comparable car model
So that the lawn mower robot moves straight, it is also equipped with a 3-axis compass. The centerpiece is a Raspberry Board Pi (€39.00 at Amazon) as a control center with a circuit board as the power section.
Tips for limiting mowing fields
So that the lawn mower robot later limits its work to the lawn and does not drive over your flower beds, it is equipped with antennas for the mowing field boundary. For this purpose, lay a simple cable with a 1 mm cross-section about 20 cm from the edge of the lawn directly under the turf.
Connect the two ends of the cable to a transmitter board. If the lawn mower robot is in operation, it continuously transmits from here at a frequency of 20 kHz. The robot's DCF77 antennas can receive this frequency. Installing these two antennas at a 45 degree angle to the left and right in front of the front axle ensures the best possible reception.
The robotic lawnmower can be stopped and turned around as soon as it moves towards the edge of the lawn and moves the front antennas over the previously laid cable.
Tip
Most projects for building robot lawn mowers yourself are still in their infancy or involve high costs. Resourceful hobbyists have decided to quickly convert their tried-and-tested petrol lawn mower into a self-propelled one. This can be achieved with the help of DC geared motors and adequate RC electronics at comparatively low cost and in a fraction of the time.
