GR-EP-45ENC 45mm 12V 20W Planetary Gearmotor with Encoder


The GR-EP-45ENC is the encoder-equipped brother of the GR-EP-45E model. It is a mid-powered 12V DC motor and planetary (epicyclic) gearbox combination, available with 5 different gearbox ratios to provide a wide variety of speed and torque outputs from the ~20W motor: 3.7:1, 19.2:1, 50.9:1, 99.5:1, 369:1.

The motor may be operated at anywhere between 3-12V DC. Operating characteristics for operation at 12V or 6V are provided under the 'technical details' tab below.

The output shaft is 10mm diameter, with a 4mm wide slot for easy mounting. Each motor is supplied with a 4-pin wired connector for use with the encoder.

Please read on below for more product details. 


£48.00 £57.60 inc VAT
Options:
Quantity:
In Stock
Group SKU: GR-EP-45ENC

This is a very useful size of motor for medium-scale automation, special effects and industrial processes. It is more powerful than most common 'hobby' gearmotors of 25mm or 36mm size, and yet not so powerful as to demand expensive high-current power & control circuitry. It is also able to handle much more torque than model gearmotors with smaller gears and/or non-planetary gearboxes.

One benefit of this model is that the relatively low motor speed (6000rpm no-load at 12V) generates lower noise levels than more-powerful motors of the same size which usually generate their power with very high rpms.

The wide range of gearbox sizes offer differing output characteristics to suit many different applications. Please see performance details listed 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 would be likely to cause the motor to overheat.

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

GR-EP-45ENC CAD rendering, Fusion 360, Contact for models

Integrated Encoder

The motor has a hall-sensor based quadrature encoder mounted to its rear, inside the black plastic rear cover. The encoder is not required for operation (and won't affect operation if left disconected), but for many projects it provides very useful feedback of the speed, and relative position, of the motor. It is accessed via a female 4-pin connector on the rear of the motor, each motor is supplied with a compatible 4-pin connector with Red, Black, Yellow and White wires. Power for the encoder (<10mA) should be provided to the Red lead (+5V VCC), and Black lead (GND/ground), ensure that the correct polarity connection is made to these wires.

It has a dual-channel output (channel A Yellow lead, Channel B White lead), with 7 complete pulses per channel, per rotation of the motor (7 PPR). One of the channels is out of phase with the other, as such it is possible to tell both the speed (from pulse frequency) and direction (by reading the pulses of one channel and comparing it to the other) of the motor. The nature of the signals that are generated is illustrated below. Given the approximate no-load motor speed of 6000rpm for the 12V motor (when at 12V) the pulse frequency may be up to 700Hz per channel if counting complete pulses, or as much as 2800Hz if your controller is counting pulse edges across both channels together (4 x counting). 

Quadrature dual-channel encoder motor direction graphical example GR-EP-45ENC motor connections diagram, rear view

The gearbox ratio multiplies the number of motor rotations for each rotation of the output shaft, for example for the 3.7:1 gearbox which has an exact ratio of 3 1217 : 1 the encoder will read 7 x 3 1217 = 25.94 (4 s.f.) pulses per encoder channel, per rotation of the output shaft. See precise ratios for the other gearbox sizes under Technical Details below.


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 3.7:1   —   Operating Characteristics 19.2:1  —   Operating Characteristics 50.9:1   —   Operating Characteristics 99.5:1   —   Operating Characteristics 369:1



Motor Dimensions

For the diagram below the dimension L is 33.6mm for the 3.7:1 gearbox, 44.9mm for the 19.2:1 gearbox, 56.2mm for the 50.9:1 and 99.5:1 gearboxes and 67.5mm for the 369:1 gearbox. Please allow for +/-1mm on overall length. CAD models are available, please contact us for a copy.

GR-EP-45ENC dimensioned diagram, 2D drawing

Gearbox Build Detail
Mounting:Four M4 x 9mm threaded holes on the front face of the gearbox (see above diagram). PCD 35mm.
Overall size:Over the end of the motor and shaft, but excluding leads options
With 3.7:1 gearbox: 45mm diameter, 154.1mm long
With 19.2:1 gearbox: 45mm diameter, 165.4mm long
With 50.9:1 gearbox: 45mm diameter, 176.7mm long
With 99.5:1 gearbox: 45mm diameter, 176.7mm long
With 369:1 gearbox: 45mm diameter, 188mm long
Body material:Steel, with copper and nickel plating
Gearbox type:Planetary/epicyclic, with three 'planet' gears per stage on large carrier pins.
The 3.7:1 gearbox has one reduction stage, the 19.2:1 has two reduction stages, the 50.9:1 and 99.5:1 each have three stages, and the 369:1 has four gearbox stages.
Apart from the 3.7:1 ratio which has all-metal gears, all other ratios have nylon planet gears on their first (input) stage for low-noise operation. The subsequent gearbox stages on the 19.2:1 onwards all use metal gears.
All gears are 0.6M pitch, the input pinion has 17 teeth.
Precise gearbox ratios:3.7:1 = 3 1217 :1
19.2:1 = 19 38187 :1
50.9:1 = 50 43974913 :1
99.5:1 = 99 10442057 :1
369:1 = 369.763 :1
Operating temperature:-5°C ~ +45°C. The motor is not suitable for unprotected outdoor use.
Shaft type:10mm by 24mm long steel, copper and nickel plated for corrosion resistance.
Features a 20mm long, 4mm wide and 2.5mm deep rectangular keyway.
Shaft support:Dual 10mm deep groove roller bearings (6900Z)
Weight:Including the supplied encoder lead, but excluding optional motor leads
With 3.7:1 gearbox: 650g
With 19.2:1 gearbox: 760g
With 50.9:1 gearbox: 875g
With 99.5:1 gearbox: 875g
With 369:1 gearbox: 990g


Motor Performance Guide (figures are for the output at the shaft, and per gearbox ratio):


3.7:1 Ratio Gearbox
at 12V DC (nominal voltage):
at 6V DC:
No-load speed after gearbox:1620rpm810rpm
No-load current:0.9A0.8A
Rated (maximum continuous) 
torque, speed:
1.6kg-cm, 1350rpm
0.80kg-cm, 675rpm
Rated load current:
3.5A2.1A
Rated load output power:22W5.5W
Maximum power torque, speed:5.2kg-cm, 810rpm2.6kg-cm, 405rpm
Maximum power current:9.7A5.0A
Maximum output power:
43W11W
Theoretical stall torque:
10.4kg-cm*5.2kg-cm*
Stall current:
18.5A*
9.3A*

The breaking (absolute maximum) output torque for the 3.7:1 gearbox is 60kg-cm (5.88Nm), 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.



19.2:1 Ratio Gearbox
at 12V DC (nominal voltage):
at 6V DC:
No-load speed after gearbox:312rpm156rpm
No-load current:0.9A0.8A
Rated (maximum continuous) 
torque, speed:
7.4kg-cm, 260rpm
3.7kg-cm, 130rpm
Rated load current:
3.5A2.1A
Rated load output power:20W5.0W
Maximum power torque, speed:24.3kg-cm, 156rpm12.2kg-cm, 78rpm
Maximum power current:9.7A5A
Maximum output power:
39W9.8W
Theoretical stall torque:
48.7kg-cm*24.3kg-cm*
Stall current:
18.5A*
9.3A*

The breaking (absolute maximum) output torque for the 19.2:1 gearbox is 180kg-cm (17.65Nm), 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 81% gearbox transfer efficiency for this gearbox, which more precisely has a 19.203209:1 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.



50.9:1 Ratio Gearbox
at 12V DC (nominal voltage):
at 6V DC:
No-load speed after gearbox:118rpm58.9rpm
No-load current:1.0A0.85A
Rated (maximum continuous) 
torque, speed:
17.8kg-cm, 98rpm
8.9kg-cm, 49rpm
Rated load current:
3.5A2.1A
Rated load output power:18W4.5W
Maximum power torque, speed:58.1kg-cm, 58.9rpm29.1kg-cm, 29.5rpm
Maximum power current:9.8A5.1A
Maximum output power:
35W8.8W
Theoretical stall torque:
116kg-cm*58.1kg-cm*
Stall current:
18.5A*
9.3A*

The breaking (absolute maximum) output torque for the 50.9:1 gearbox is 360kg-cm (35.3Nm), 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 73% gearbox transfer efficiency for this gearbox, which more precisely has a 50.89497252:1 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.



99.5:1 Ratio Gearbox
at 12V DC (nominal voltage):
at 6V DC:
No-load speed after gearbox:60.3rpm30.1rpm
No-load current:1.0A0.85A
Rated (maximum continuous) 
torque, speed:
34.7kg-cm, 50rpm
17.4kg-cm, 25rpm
Rated load current:
3.5A2.1A
Rated load output power:18W4.5W
Maximum power torque, speed:114kg-cm, 30rpm56.8kg-cm, 15rpm
Maximum power current:9.8A5.1A
Maximum output power:
35W8.8W
Theoretical stall torque:
227kg-cm*114kg-cm*
Stall current:
18.5A*
9.3A*

The breaking (absolute maximum) output torque for the 99.5:1 gearbox is is 360kg-cm (35.3Nm), 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.



369:1 Ratio Gearbox
at 12V DC (nominal voltage):
at 6V DC:
No-load speed after gearbox:16.3rpm8.14rpm
No-load current:1.2A1.0A
Rated (maximum continuous) 
torque, speed:
114.6kg-cm, 13.6rpm
57.3kg-cm, 6.78rpm
Rated load current:
3.5A2.2A
Rated load output power:16W4.0W
Maximum power torque, speed:375kg-cm, 8.14rpm*188kg-cm, 4.07rpm
Maximum power current:9.9A*5.1A
Maximum output power:
31W*7.8W
Theoretical stall torque:
750kg-cm*375kg-cm*
Stall current:
18.5A*
9.3A*

*Highlighted values should not be reached. The breaking (absolute maximum) output torque for the 369:1 ratio is 360kg-cm (35.3Nm), 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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