GR-EP-45E Medium Power 45mm 12V Planetary Gearmotor

This model of gearmotor is able to provide sufficient torque for many automation and special effects projects without requring unusually large power supplies and control hardware. It is more powerful than most common 'hobby' gearmotors and yet not so powerful as to demand very high currents (for example its higher-powered brother the GR-EP-45 can demand up to 70A at 12V). Another benefit of this range is that the low motor speed generates relatively low noise levels over more powerful motors.

The 19.2:1 gearbox option provides a higher speed but lower torque output (313rpm no-load at 12V), the 99.5:1 option compromises between torque and speed (60rpm no-load), while the 369:1 sacrifices speed for a very high torque output (16.2rpm no-load). More operating details are available under Technical Details below. If you intend to operate the motor with a continuous load do not exceed the continuous torque ratings described for the different gearbox options, running at a higher torque than these ratings for extended periods of time could lead the motor to overheat.

The maximum allowable torque through the gearbox for any of the ratio options is 250kg-cm (24.5Nm) beyond which the gears may be damaged, be sure to fit either current limiting or output load limiting hardware if there is a danger that your application may try to exceed this load. 

Two copper tabs at the back of the motor body can be used to solder or crimp wires to (the tabs are suitable for 4.8mm female spade connectors). We offer an option for 500mm long silicone-insulated leads (1mm²) to be installed (soldered to the motor tabs) ready for use which can be selected above. Allow for one extra working day to process your order if a lead option is added, since this option is added to-order.

User advice

This motor operates like any other DC motor and so may be used at voltages other than the nominal 12V with changed operating characteristics (please be aware that the warranty does not cover operation above 12V which is likely to shorten the lifespan). Reducing the voltage reaching the motor will decrease the output speed and current for a given load, while increasing the voltage will increase the speed and the current. To change the direction of rotation swap the polarity of the power to the motor contacts (invert positive and negative). The motor is neutrally timed and so will travel at approximately the same speed in both directions.

It is recommended to 'break-in' a new motor and gearbox before use, this is done by running for 3-4 minutes continuously in both directions (polarity one way then the other) under no load. This ensures that all of the gears and bearings are running freely before being subjected to loading.

Jump to section:    Motor Dimensions   —   Gearbox Build Detail   —   Operating Characteristics 19.2:1   —   Operating Characteristics 99.5:1   —   Operating Characteristics 369:1

Motor Dimensions

For the diagram below the dimension L is 45.5mm for the 19.2:1 gearbox, 56.5mm for the 99.5:1 gearbox and 68mm for the 369:1 gearbox. Please allow for +/-1mm on overall length. CAD models are available, please contact us for a copy.

Gearbox Build Detail

Operating Characteristics with 19.2:1 ratio gearbox (values at output from gearbox)

*Warning: Avoid reaching stall by adding circuit or load protection, the motor will quickly overheat and be damaged if it is held in a stall condition

Please be aware that some of the values above are extrapolated from other measurements and there will be a small degree of variance from motor to motor, allow for a safety factor of 10% above/below the given values when designing for your application. Be sure that any equipment that you use with the motor (power source and controller) is capable of handling the currents that the motor may demand.

Operating Characteristics with 99.5:1 ratio gearbox (values at output from gearbox)

*Warning: Avoid reaching stall by adding circuit or load protection, the motor will quickly overheat and be damaged if it is held in a stall condition

Please be aware that some of the values above are extrapolated from other measurements and there will be a small degree of variance from motor to motor, allow for a safety factor of 10% above/below the given values when designing for your application. Be sure that any equipment that you use with the motor (power source and controller) is capable of handling the currents that the motor may demand.

Operating Characteristics with 369:1 ratio gearbox (values at output from gearbox)

*Warning: Do not allow this motor and gearbox combination to exceed 250kg-cm (24.5Nm) at the output, loads greater than this will permanently damage the gearbox. If limiting the input current to protect the gearbox then ensure that it is kept below the maximum values given above.

Please be aware that some of the values above are extrapolated from other measurements and there will be a small degree of variance from motor to motor, allow for a safety factor of 10% above/below the given values when designing for your application. Be sure that any equipment that you use with the motor (power source and controller) is capable of handling the currents that the motor may demand.