The JECCbot mini is a open source robotics platform. Just print it on your 3D printer, mount motors and wheels, add electronics like Arduino or Raspberry Pi and you are ready to start with your own robot. The robot is suitable for outdoor task. It has enough clearance to climb over small obstacles like stones and has enough power to climb hills.
The chassis is 40 cm long and 20 cm wide. The finished robot is about 45 cm long and 35 cm wide and weights about 1.5 kg depending on the parts you choose.
A list with compatible parts like motors and wheels is provided on github in the readme and in the project wiki.