195:1 Metal Gearmotor 20Dx44L mm 6V with Extended Motor Shaft
These cylindrical brushed DC gearmotors are available in a wide range of gear ratios, from 25:1 up to 488:1, and with three different motors: 6 V and 12 V motors with long-life carbon brushes (CB), and a 6 V motor with shorter-life precious metal brushes. All three motors offer similar performances at their respective nominal voltages, just with the 12 V motor drawing approximately half the current of the 6 V motor and with the carbon brush versions having longer lifetimes than the one with precious metal brushes.
The CB versions (shown on the right in the picture below), can be differentiated from versions with percious metal brushes (shown on the left) by their copper-colored terminals.
These gearmotors are optionally available with an additional 2 mm-diameter output shaft that protrudes 6 mm from the rear of the motor (see the middle picture below). This rear shaft rotates at the same speed as the input to the gearbox and offers a way to add an encoder, such as our magnetic encoder for 20D mm metal gearmotors as shown in the right picture below, to provide motor speed or position feedback.
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20D mm metal gearmotor CB with long-life carbon brushes.
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20D mm metal gearmotor CB with long-life carbon brushes and an extended motor shaft.
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Magnetic Encoder Kit for 20D mm Metal Gearmotors assembled on a 20D mm metal gearmotor with extended motor shaft.
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The gearmotors all have 20 mm diameter gearboxes and 4 mm diameter gearbox output shafts, so it is generally easy to swap one version for another if your design requirements change (though the length of the gearbox tends to increase with the gear ratio).
Please see the 20D metal gearmotor datasheet (1MB pdf) for more information, including detailed performance graphs for each 6V CB and 12V CB version. You can also use our dynamically sortable 20D mm metal gearmotor comparison table for the gearmotor that offers the best blend of speed, torque, and current-draw for your particular application.
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 5 kg-cm (70 oz-in) for the versions with carbon brushes (12V CB and 6V CB) and under 3.5 kg-cm (50 oz-in) for the versions with precious metal brushes. Stalls can also result in rapid (potentially on the order of seconds) thermal damage to the motor windings and brushes, especially for motors like this that can deliver a lot of power for their size; a general recommendation for brushed DC motors is to limit continuous current to approximately 25% of the stall current.
In general, these kinds of motors can run at voltages above and below their nominal voltages; lower voltages might not be practical, and higher voltages could start negatively affecting the life of the motor.
Details for item #3469
Exact gear ratio: 28×25×25×25×25×2514×10×10×10×10×10=195.3125:128×25×25×25×25×2514×10×10×10×10×10=195.3125:1
Dimensions
The diagram below shows the dimensions of the 20D mm line of metal gearmotors (units are mm over [inches]).
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Dimensions of the Pololu 20D mm metal gearmotors. Units are mm over [inches]. This diagram only applies to the listed gear ratios.
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Gearmotor accessories
The gearmotor face plate has two mounting holes threaded for M2.5 screws, and you can use our custom-designed 20D mm metal gearmotor bracket (shown in the left picture below) to mount the gearmotor to your project via these mounting holes and the screws that come with the bracket.
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Pololu 20D mm metal gearmotor bracket pair with included hardware.
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20D mm metal gearmotor with a univeral aluminum mounting hub and mounted on a 20D mm metal gearmotor bracket.
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Tradução em Português brevemente disponível!
