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GR-EP-56 12V DC 56mm 40W Planetary Gearmotor


The GR-EP-56 is a medium-power 12V DC motor and planetary (epicyclic) gearbox combination, available with either a low-reduction 15.3:1 gearbox for relatively high speed output, a mid-range 102:1 gearbox, or a high-reduction high torque but low-speed 326:1 gearbox. 

The gearbox is designed to be robust, with a 12mm diameter output shaft, and with MOD 1 size gears for high torque handling. Operating characteristics are provided for the different gearbox options under the 'Technical Details' section below.

Each gearmotor assembly is 56mm in diameter with overall (motor & gearbox) lengths of 178mm with the 15.3:1 gearbox, 192mm with the 102:1 gearbox, or 206mm with the 326:1 gearbox. Please read on below for more specifications. 


£76.00 £91.20 inc VAT
Options:
Quantity:
In Stock
Group SKU: GR-EP-56

This medium-size motor offers a useful power output with relatively low noise compared to many smaller-diameter motors. The '997' type motor, larger than more-common 550 and 775 motor can sizes, generates a higher torque at a lower speed (4900rpm no-load at 12V DC) when compared to its smaller cousins. The larger motor size also means that higher power outputs can be sustained for longer periods with reduced risk of overheating. 

The 56mm diameter gearbox, available in three different gear ratios, features MOD 1 pitch gears for high torque handling. The first stage of each gearbox uses nylon planet gears to reduce noise levels, with all subsequent reduction stages using steel gears.

The motor features an internal cooling fan to accommodate high power output (and the resultant heat production). Ensure that the air-vents at the rear of the motor are not obstructed when the motor is in operation.

Three gearbox options are available offering different output speed & torque combinations. The 15.3:1 gearbox option provides a higher speed but lower torque output (320rpm no-load at 12V), the 102:1 option compromises between torque and speed (48rpm no-load), while the 326:1 sacrifices speed for a very high torque output (15rpm 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.

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 (1.5mm2) to be installed (soldered directly 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. If you require a custom wiring or control option please contact us to discuss specifications and pricing. 

CAD models are available, please contact us for a copy.

GR-EP-56 12V DC electric motor CAD render overview

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). This is usually done via a control switch or controller, for example our rocker switch harness or GLA-CU-X3 control units.

You should fit circuit protection to protect both the motor from stalling/overheating and your power source from overload. At a minimum this would be a fuse in series with a motor, but you might want to fit a more sophisticated protection device such as the GR-SENS instead.

Make sure to read the performance tables for your selected gearbox option under 'Technical Details' below, so that you have an understanding of the torque, current and speed that you can expect from the motor. If you're unsure about selecting the appropriate motor for the task please send details of your application to us and we'll guide you through the options. 

Jump to section:    Motor Dimensions   —   Gearbox Build Detail   —   Operating Characteristics 15.3:1   —   Operating Characteristics 102:1   —   Operating Characteristics 326:1



Motor Dimensions

For the diagram below the dimension L is 54.2mm for the 15.3:1 gearbox, 68.1mm for the 102:1 gearbox and 82mm for the 326:1 gearbox. Please allow for +/-1mm on overall length. 

GR-EP-56 Planetary Gearmotor dimensioned diagram, 2D CAD drawing view


Gearbox Build Detail
Mounting:Four M5 x 8mm threaded holes on the front face of the gearbox (see above diagram). PCD 45mm.
Overall size:Over the end of the motor and shaft, but excluding leads options
With 15.3:1 gearbox: 56mm diameter, 178mm long
With 102:1 gearbox: 56mm diameter, 192mm long
With 326:1 gearbox: 56mm diameter, 206mm long
Body material:Steel, with copper and nickel plating
Gearbox type:Planetary/epicyclic, with three 'planet' gears per stage on large carrier pins.
The 15.3:1 gearbox has two reduction stages, the 102:1 has three stages and the 326:1 has four gearbox stages.
The first gearbox stage of each gearbox has nylon planet gears for low-noise operation, the output stage uses steel gears.
All gears are a relatively large MOD 1 size, for high torque handling.
Precise gearbox ratios:15.3:1
102.4:1
326 65256 :1
Operating temperature:-5°C ~ +45°C. The motor is not suitable for unprotected outdoor use.
Shaft type:12mm by 25mm long steel, copper and nickel plated for corrosion resistance.
Features a 20mm long, 4mm wide and 2.5mm deep rectangular keyway.
Shaft support:Dual 12mm deep groove ball bearings (16001ZZ, 12x28x7mm each)
Weight:Excluding leads options
With 15.3:1 gearbox: 1320g
With 102:1 gearbox: 1520g
With 326:1 gearbox: 1710g



Motor performance guide for each gearbox option:


15.3:1 Ratio Gearbox
at 12V DC (nominal voltage):
at 6V DC:
No-load speed after gearbox:320rpm160rpm
No-load current:1.2A1.1A
Rated (maximum continuous) 
torque, speed:
11.5kg-cm, 276rpm
5.7kg-cm, 138rpm
Rated load current:
4.2A2.1A
Rated load output power:32.6W8.1W
Maximum power torque, speed:62kg-cm, 160rpm31kg-cm, 80rpm
Maximum power current:21.6A11.1A
Maximum output power:
102W25W
Theoretical stall torque:
124kg-cm*62kg-cm*
Stall current:
42A*
21A*

The maximum-rated output torque for the 15.3:1 gearbox is 300kg-cm (29.4Nm), be wary of shock/impact loads that could exceed this.

*Highlighted values should not be reached. You should use mechanical and/or current-based protection to protect the motor from overload (using for example a clutch, fuse, or digital current limiting switch), since if is operated at too high a sustained load, or allowed to stall, the motor could quickly overheat.

Please be aware that many of the values above are extrapolated from other measurements and there will be some variance from motor to motor, allow for a safety factor of at least 15% above/below the given values when designing for your application. Output torque and power values are based upon an average 90% gearbox transfer efficiency for this gearbox, which more precisely has a 3.706:1 ratio. The continuous duty rating is based upon there being sufficient cooling for the motor and gearbox, the operating temperature should be kept below 45°C and free air flow should be ensured to prevent overheating. 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.



102:1 Ratio Gearbox
at 12V DC (nominal voltage):
at 6V DC:
No-load speed after gearbox:48rpm24rpm
No-load current:1.3A1.2A
Rated (maximum continuous) 
torque, speed:
69.3kg-cm, 41rpm
34.6kg-cm, 21rpm
Rated load current:
4.2A2.1A
Rated load output power:29.4W7.3W
Maximum power torque, speed:374kg-cm, 24rpm187kg-cm, 12rpm
Maximum power current:21.7A11.1A
Maximum output power:
92W23W
Theoretical stall torque:
747kg-cm*374kg-cm*
Stall current:
42A*
21A*

The maximum-rated output torque for the 102:1 gearbox is 600kg-cm (58.8Nm), try to prevent shock/impact loads that could exceed this. 

*Highlighted values should not be reached. You should use mechanical and/or current-based protection to protect the motor from overload (using for example a clutch, fuse, or digital current limiting switch), since if is operated at too high a sustained load, or allowed to stall, the motor could quickly overheat.

Please be aware that many of the values above are extrapolated from other measurements and there will be some variance from motor to motor, allow for a safety factor of at least 15% above/below the given values when designing for your application. Output torque and power values are based upon an average 81% gearbox transfer efficiency for this gearbox, which more precisely has a 13.734:1 ratio. The continuous duty rating is based upon there being sufficient cooling for the motor and gearbox, the operating temperature should be kept below 45°C and free air flow should be ensured to prevent overheating. 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.



326:1 Ratio Gearbox
at 12V DC (nominal voltage):
at 6V DC:
No-load speed after gearbox:15.0rpm7.51rpm
No-load current:1.4A1.3A
Rated (maximum continuous) 
torque, speed:
197kg-cm, 13.0rpm
98.3kg-cm, 6.48rpm
Rated load current:
4.2A2.1A
Rated load output power:26.2W6.5W
Maximum power torque, speed:1060kg-cm, 7.51rpm*530kg-cm, 3.75rpm
Maximum power current:21.7A*11.2A
Maximum output power:
82W*20W
Theoretical stall torque:
2120kg-cm*1060kg-cm*
Stall current:
42A*
21A*

*Highlighted values should not be reached. The maximum-rated gearbox output torque is 600kg-cm (58.8Nm), you should use mechanical and/or current-based protection to protect the motor from overload (using for example a clutch, fuse, or digital current limiting switch), since the motor is capable of generating a much greater torque than the output stage of the gearbox can handle. 

Please be aware that many of the values above are extrapolated from other measurements and there will be some variance from motor to motor, allow for a safety factor of at least 15% above/below the given values when designing for your application. Output torque and power values are based upon an average 73% gearbox transfer efficiency for this gearbox, which more precisely has a 50.895:1 ratio. The continuous duty rating is based upon there being sufficient cooling for the motor and gearbox, the operating temperature should be kept below 45°C and free air flow should be ensured to prevent overheating. 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.



If you have any questions about this item, including for information on custom ratios, controllers, and bulk pricing, then please contact us.

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