19:1 Metal Gearmotor 37Dx52L mm (Helical Pinion)

This gearmotor is a powerful brushed DC motor with 18.75:1 metal gearbox intended for operation at 12 V. The gearbox is composed mainly of spur gears, but it features helical gears for the first stage for reduced noise and improved efficiency.

AUD$ 58.95

In stock in Australia  

Shipping from $7.90

+174 more from our supplier in 7-10 days

Our Code: SKU-005596

Supplier Link: [Pololu MPN:4741]


Description

Overview

This powerful brushed DC gearmotor is available in six different gear ratios. Versions with an integrated quadrature encoder are also available, including just the motor and encoder portion by itself (no gearbox).

Rated
Voltage
Stall
Current
No-Load
Current
Gear Ratio No-Load Speed
(RPM)
Extrapolated
Stall Torque
Max Power
(W)


Without Encoder


With Encoder
(kg ⋅ cm) (oz ⋅ in)
12 V 5.5 A 0.15 A 1:1 (no gearbox) 10,000 0.5 7 item #4750
19:1 540 8.5 120 12 item #4741 item #4751
30:1 330 14 190 12 item #4742 item #4752
50:1 200 21 290 10 item #4743 item #4753
70:1 150 27 380 10 item #4744 item #4754
100:1 100 34 470 8 item #4745 item #4755
131:1 76 45 630 6 item #4746 item #4756
150:1 67 49 680 6 item #2829 item #2828

Note: Stalling or overloading gearmotors can greatly decrease their lifetimes and even result in immediate damage. In order to avoid damaging the gearbox, we recommend keeping continuously applied loads under 10 kg-cm (150 oz-in), and the recommended upper limit for instantaneous torque is 25 kg-cm (350 oz-in). Stalls can also result in rapid (potentially on the order of seconds) thermal damage to the motor windings and brushes; a general recommendation for brushed DC motor operation is 25% or less of the stall current.

These motors are intended for use at 12 V, though in general, these kinds of motors can run at voltages above and below the nominal voltage (they can begin rotating at voltages as low as 1 V). Lower voltages might not be practical, and higher voltages could start negatively affecting the life of the motor.

Details for item #4741

Exact gear ratio: ``(25×30×30) / (10×10×12) = bb(18.75:1)``

This gearmotor is a powerful brushed DC motor with 18.75:1 metal gearbox intended for operation at 12 V. These units have a 16 mm-long, 6 mm-diameter D-shaped output shaft. This gearmotor is also available with an integrated encoder.

Key specifications:

voltage no-load performance stall extrapolation
12 V 540 RPM, 150 mA 8.5 kg⋅cm (120 oz⋅in), 5.5 A

Gearmotor accessories

The face plate has six mounting holes evenly spaced around the outer edge threaded for M3 screws. These mounting holes form a regular hexagon and the centers of neighbouring holes are 15.5 mm apart. We carry two brackets for these gearmotors: a stamped aluminium L-bracket (sold in pairs) and a sturdier, tombstone-style machined aluminium bracket (sold individually):

37D mm gearmotor (without encoder) with L-bracket and 6mm universal mounting hub. (2) (2)

Pololu machined aluminium bracket for 37D mm metal gearmotors mounting a motor to a clear piece of acrylic.

The 6 mm diameter gearbox output shaft works with the Pololu universal aluminium mounting hub for 6mm shafts, which can be used to mount our larger Pololu wheels (80mm- and 90mm-diameter) or custom wheels and mechanisms to the gearmotor’s output shaft as shown in the left picture below. Alternatively, you could use our 6mm scooter wheel adaptor to mount many common scooter, skateboard, and inline skate wheels to the gearmotor’s output shaft as shown in the right picture below:

Black Pololu Wheel 90×10mm on a Pololu 37D mm Metal Gearmotor.

A 37D mm gearmotor connected to a scooter wheel by the 6 mm scooter wheel adaptor.

For a general-purpose hex adaptor, consider our 12mm hex wheel adaptor (also available in an extended version), which lets you use these motors with many common hobby RC wheels, including Dagu Wild Thumper Wheels:

12mm Hex Wheel Adaptor for 6mm Shaft connecting a Wild Thumper Wheel to a 37D mm Metal Gearmotor.

We have a number of motor drivers and motor controllers that work with these 37D mm metal gearmotors. We generally recommend our High-Power Motor Drivers, which are available in various power levels and versions, including some dual-channel shields for Arduino and dual-channel expansion boards for Raspberry Pi. Additionally, our VNH5019-based motor drivers, which are also available as single and dual carriers, are a good match for these gearmotors.

Pololu Dual G2 High-Power Motor Driver 24v14 Shield for Arduino.

Pololu Dual G2 High-Power Motor Driver 24v14 for Raspberry Pi (assembled version) with included hardware.

Pololu dual VNH5019 motor driver shield for Arduino.

If you are looking for higher-level control interfaces, such as USB, RC, analogue voltages, I²C, or TTL serial, consider our Simple Motor Controllers, Jrk motor controllers, or RoboClaw motor controllers; these controllers are available in various power levels several of which can handle these 37D mm metal gearmotors (we generally recommend a motor controller that can handle continuous currents above the stall current of your motor).

High-Power Simple Motor Controller G2 18v15.

Jrk G2 21v3 USB Motor Controller with Feedback.

RoboClaw 2×7A Motor Controller (V5B) in its included case.

We have an assortment of Hall effect-based current sensors to choose from for those who need to monitor motor current:

ACS711EX current sensor carrier -15.5A to +15.5A.

ACS714 current sensor carrier -5A to +5A.

Dimensions

Dimensions of the 37D mm metal gearmotor (without encoder). Units are mm over [inches].

This diagram is also available as a downloadable PDF (461k pdf).

Warning: Do not screw too far into the mounting holes as the screws can hit the gears. We recommend screwing no further than 3mm (1/8″) into the screw hole.

37D mm metal gearmotor next to a micro metal gearmotor for size comparison.


Selecting the Right Gearmotor

We offer a wide selection of metal gearmotors that offer different combinations of speed and torque. Our metal gearmotor comparison table can help you find the motor that best meets your project’s requirements.


Specifications

Dimensions

Size: 37D × 52L mm1
Weight: 185 g
Shaft diameter: 6 mm2

General specifications

Gear ratio: 18.75:1
No-load speed @ 12V: 540 rpm
No-load current @ 12V: 0.15 A
Stall current @ 12V: 5.5 A3
Stall torque @ 12V: 8.5 kg·cm3
Max output power @ 12V: 12 W
No-load speed @ 6V: 270 rpm4
No-load current @ 6V: 0.1 A4
Stall current @ 6V: 3.0 A5
Stall torque @ 6V: 5.0 kg·cm5

Performance at maximum efficiency

Max efficiency @ 12V: 55 %
Speed at max efficiency: 470 rpm
Torque at max efficiency: 1.0 kg·cm
Current at max efficiency: 0.76 A
Output power at max efficiency: 5.0 W

General specifications

Encoders?: N

Notes:

1
Length measurement is from gearbox face plate to back of motor (it does not include the output shaft or motor terminals). See dimension diagram for details.
2
D shaft.
3
Stalling is likely to damage the gearmotor. Stall parameters come from a theoretical extrapolation of performance at loads far from stall. As the motor heats up, as happens as it approaches an actual stall, the stall torque and current decrease.
4
This motor will run at 6 V but is intended for operation at 12 V.
5
Stalling is likely to damage the gearmotor. Stall parameters come from a theoretical extrapolation of performance at loads far from stall. This motor will run at 6 V but is intended for operation at 12 V.

Resources

File downloads

Dimension diagram of the Pololu 37D mm Metal Gearmotors (461k pdf)
3D models of 37D mm gearmotors (5MB zip)
This file contains 3D models (in the step file format) of the 37D mm gearmotors with and without encoders.

Recommended links

MATLAB script to plot motor performance curves for Pololu brushed DC gearmotors
This MATLAB script, written by Ali Asgher Mansoor Habiby, plots speed, power, current draw, and efficiency as they vary with torque when you input the gearmotor specifications. It also prints the resistance of the motor, and the current draw and torque at which maximum efficiency and maximum power occur.

FAQs

What material is the gearbox output shaft made of, and can I get the shaft customised?
The shaft is composed of hardened stainless steel. Some customisation is generally possible (e.g., different length or no D-shaft) for sufficiently high-volume orders. If this is something you are interested in, please email us.
I need additional information about this motor; do you have a datasheet?

No; the information we have available for this motor can be found on its product page. However, you can approximate various additional motor parameters from the information found in the “Specs” tab.

The electrical resistance of the motor can be approximated by dividing the rated voltage by the stall current (at the rated voltage). The electromotive force constant (Ke) can be approximated by dividing the rated voltage by the free-run speed (at the rated voltage). To approximate the motor torque constant (Kt), you can divide the stall torque by the stall current.

For pretty much any DC motor, the current, speed, power, and efficiency curves as a function of torque will look like those in the graph below (assuming motor voltage and temperature are constant):

The current and speed curves are approximately linear, and the product pages for our motors provide the approximate end points for these lines: (0 torque, no-load current) and (stall torque, stall current) for the red line, and (0 torque, no-load speed) and (stall torque, 0 speed) for the blue line.

The orange output power curve is the product of the speed and the torque, which results in an inverted parabola with its peak at 50% of the stall torque.

The green efficiency curve is the output power divided by the input power, where the input power is current times voltage. The voltage is constant, so you can divide the output power curve by the current line to get the general shape of the efficiency curve, which in turn lets you identify the torque, speed, and current that correspond to max efficiency.

There are many programs out there that you can use to generate these curves. For example, if you have access to MATLAB, you can use this customer-created MATLAB script to generate these motor plots for you from the specifications we provide for each gearmotor.

Note: A good general rule of thumb is to keep the continuous load on a DC motor from exceeding approximately 20% to 30% of the stall torque. Stalling gearmotors can greatly decrease their lifetimes, occasionally resulting in immediate damage to the gearbox or thermal damage to the motor windings or brushes. Do not expect to be able to safely operate a brushed DC gearmotor all the way to stall. The safe operating range will depend on the specifics of the gearmotor itself.

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