https://www.instructables.com/Servo-Driven-Tracked-Rover-Wsuspensions-self-Tight/
3D Printed Servo Driven Tracked Rover W/suspensions (self Tightning Belts) : 4 Steps - Instructables
3D Printed Servo Driven Tracked Rover W/suspensions (self Tightning Belts): There are ment to be glued on some rubber square`s at the flat side of the tracks...