The 20mm general gearmotors are widely used on Intelligent robots,intelligent manipulators, intelligent furnitures, Intelligent focusing systems etc. Those are incredibly tough and feature full metal gears. Have gear ratio 12.5:1 to 488:1, 590rpm~15rpm, stall torque 0.6~7Kg.cm
Type: MG20E-06190-25
Features:
Voltage: 6-9 Volts
Gear Ratio: 25:1
Stall Torque:0.6Kg.cm (6V)
No load Speed: 290RPM (6V)
No Load Current: 150mA (6V)
Rated: 0.4Kg.cm,220rpm,0.6A
Stall Current: 2.0A (6V)
AB phase 11ppr Hall Sensor Encoder
(data sheet at: 6V 290rpm 25:1 )