This set of wheelchair motors makes great heavy duty robot motors. One left motor and one right motor. They are right angle gear drives have been modified to include encoders. They are 24VDC and the operating speed is 120 RPM.
This is a 4WD IG42-SB platform that is set up for outdoor positioning and autonomous navigation. The ATR robot is powered by an on-board CubePilot system that's built on top of the versatile and open source ArduPilot software suite. Replaces TP-600-455.