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

Custom options are also available, please contact us for more information

The GR-EP-45ENC is the encoder-equipped brother of the GR-EP-45E gearmotor 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 are given for operation at 12V or 6V further down the page.

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.

 

Regular price £48.80
Regular price Sale price £48.80
(each, exc VAT)

Availability: IN STOCK

SKU: GR-EP-45ENC_3.7


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 (upwards of 20,000rpm for some drill motors).
  
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, mentioning the gearbox ratio(s) that you require models for.
 
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).
  
 
Actuator Motor and Encoder Circuit Connections Diagram
  
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 the torque, while increasing the voltage will increase the speed and the torque (torque is directly related to 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 GR-MOT1 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, for adjustable protection.
  
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 any details of your application that you have over to us and we'll talk through the options.
 
Compliance
These motors adhere to RoHS limits (UKCA declaration of conformity is available upon request). EMC compliance should be assessed/tested for in the end application since these motors are generic components whose electrical characteristics, including radiated emissions, are very dependent upon the power source, controller, wiring, load and operating environment/housing. 
  
  
  
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 188:1 or 369:1 gearbox. Please allow for +/-1mm on overall length. CAD models are available, please contact us for a copy.

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 188:1 gearbox: 45mm diameter, 188mm 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 188:1 and 369:1 each have four gearbox stages.
 Apart from the 3.7:1 ratio which has all-metal gears, all other ratios have POM planet gears on their first (input) stage for lower-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
188:1 = 188.611 :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
  
  
 
Operating characteristics, 3.7:1 ratio (values at output from gearbox)
 
at 12V DC
at 6V DC
No-load speed
1620rpm
810rpm
No-load current
0.8A
0.7A
Continuous rated torque, speed
1.6kg-cm, 1350rpm
0.8kg-cm, 675rpm
Continuous current
3.5A
2.1A
Continuous output power
22W
5.5W
Max. power torque, speed
5.2kg-cm, 810rpm
2.6kg-cm, 405rpm
Max. power current
9.7A
5.0A
Stall torque
10kg-cm
5.2kg-cm
Stall current
18.6A
9.3A
  

The breaking (maximum rated) output torque of the 3.7:1 ratio gearbox is 60kg-cm, be careful to avoid shock/impact loads that could exceed this.
Please be aware that some of the values above are extrapolated from other measurements and it's normal for there to be a small degree of variance from motor to motor, you should allow for a safety factor of at least 10% above/below the given values when designing for your application. The output figures provided are based upon an average 90% gearbox efficiency for the 3.7:1 ratio gearbox. 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, whilst also being able to limit the current to protect the motor in the event of it stalling.

 
Operating characteristics, 19.2:1 ratio (values at output from gearbox)
 
at 12V DC
at 6V DC
No-load speed
312rpm
156rpm
No-load current
0.8A
0.7A
Continuous rated torque, speed
7.4kg-cm, 260rpm
3.7kg-cm, 130rpm
Continuous current
3.5A
2.1A
Continuous output power
20W
5.0W
Max. power torque, speed
24kg-cm, 156rpm
12kg-cm, 78rpm
Max. power current
9.7A
5.0A
Stall torque
48kg-cm
24kg-cm
Stall current
18.6A
9.3A
  

The breaking (maximum rated) output torque of the 19.2:1 ratio gearbox is 180kg-cm, be careful to avoid shock/impact loads that could exceed this.
Please be aware that some of the values above are extrapolated from other measurements and it's normal for there to be a small degree of variance from motor to motor, you should allow for a safety factor of at least 10% above/below the given values when designing for your application. The output figures provided are based upon an average 81% gearbox efficiency for the 19.2:1 ratio gearbox. 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, whilst also being able to limit the current to protect the motor in the event of it stalling.

 
Operating characteristics, 50.9:1 ratio (values at output from gearbox)
 
at 12V DC
at 6V DC
No-load speed
118rpm
59rpm
No-load current
0.8A
0.7A
Continuous rated torque, speed
18kg-cm, 98rpm
8.9kg-cm, 49rpm
Continuous current
3.5A
2.1A
Continuous output power
18W
4.5W
Max. power torque, speed
58kg-cm, 59rpm
29kg-cm, 30rpm
Max. power current
9.7A
5.0A
Stall torque
116kg-cm
58kg-cm
Stall current
18.6A
9.3A
  

The breaking (maximum rated) output torque of the 50.9:1 ratio gearbox is 300kg-cm, be careful to avoid shock/impact loads that could exceed this.
Please be aware that some of the values above are extrapolated from other measurements and it's normal for there to be a small degree of variance from motor to motor, you should allow for a safety factor of at least 10% above/below the given values when designing for your application. The output figures provided are based upon an average 73% gearbox efficiency for the 50.9:1 ratio gearbox. 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, whilst also being able to limit the current to protect the motor in the event of it stalling.

 
Operating characteristics, 99.5:1 ratio (values at output from gearbox)
 
at 12V DC
at 6V DC
No-load speed
60rpm
30rpm
No-load current
0.8A
0.7A
Continuous rated torque, speed
35kg-cm, 50rpm
17kg-cm, 25rpm
Continuous current
3.5A
2.1A
Continuous output power
18W
4.5W
Max. power torque, speed
114kg-cm, 30rpm
57kg-cm, 15rpm
Max. power current
9.7A
5.0A
Stall torque
227kg-cm
114kg-cm
Stall current
18.6A
9.3A
  

The breaking (maximum rated) output torque of the 99.5:1 ratio gearbox is 300kg-cm, be careful to avoid shock/impact loads that could exceed this.
Please be aware that some of the values above are extrapolated from other measurements and it's normal for there to be a small degree of variance from motor to motor, you should allow for a safety factor of at least 10% above/below the given values when designing for your application. The output figures provided are based upon an average 73% gearbox efficiency for the 99.5:1 ratio gearbox. 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, whilst also being able to limit the current to protect the motor in the event of it stalling.

 
Operating characteristics, 188:1 ratio (values at output from gearbox)
 
at 12V DC
at 6V DC
No-load speed
32rpm
16rpm
No-load current
0.8A
0.7A
Continuous rated torque, speed
58kg-cm, 27rpm
29kg-cm, 13rpm
Continuous current
3.5A
2.1A
Continuous output power
16W
4.0W
Max. power torque, speed
192kg-cm, 16rpm
95kg-cm, 8.0rpm
Max. power current
9.7A
5.0A
Stall torque
383kg-cm
191kg-cm
Stall current
(18.6A)
9.3A
Breaking current
17A
-
  

The breaking (maximum rated) output torque of the 188:1 ratio gearbox is 300kg-cm. Ensure that the motor output is limited to well below the values highlighted in red, to prevent the motor from damaging itself by exceeding this maximum load.
Please be aware that some of the values above are extrapolated from other measurements and it's normal for there to be a small degree of variance from motor to motor, you should allow for a safety factor of at least 10% above/below the given values when designing for your application. The output figures provided are based upon an average 65% gearbox efficiency for the 188:1 ratio gearbox. 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, whilst also being able to limit the current to protect the motor in the event of it stalling.

 
Operating characteristics, 369:1 ratio (values at output from gearbox)
 
at 12V DC
at 6V DC
No-load speed
16rpm
8.1rpm
No-load current
0.8A
0.7A
Continuous rated torque, speed
114kg-cm, 14rpm
57kg-cm, 6.8rpm
Continuous current
3.5A
2.1A
Continuous output power
16W
4.0W
Max. power torque, speed
375kg-cm, 8.1rpm
187kg-cm, 4.1rpm
Max. power current
(9.7A)
5.0A
Stall torque
750kg-cm
375kg-cm
Stall current
(18.6A)
(9.3A)
Breaking current
9A
9A
  

The breaking (maximum rated) output torque of the 369:1 ratio gearbox is 300kg-cm. Ensure that the motor output is limited to well below the values highlighted in red, to prevent the motor from damaging itself by exceeding this maximum load.
Please be aware that some of the values above are extrapolated from other measurements and it's normal for there to be a small degree of variance from motor to motor, you should allow for a safety factor of at least 10% above/below the given values when designing for your application. The output figures provided are based upon an average 65% gearbox efficiency for the 369:1 ratio gearbox. 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, whilst also being able to limit the current to protect the motor in the event of it stalling.