Makeblock mBot Construction Manual page 4

Sensor Bumper Upgrade
Use 1 x M3X12mm Bolt and 1 x M3 Nut
to secure Ultrasonic Distance Sensor and
face plate in 3D Printed Bumper
(Below)
Use 4 x M3X 10mm Bolts and 4 x M3
Nuts to secure 2 x Light Sensors in 3D
Printed Bumper
(Above)
Use 2 x M5X8mm Bolts to
anchor Face Plate
(Above)