Pololu 24V 37Dx65L mm 6.3:1 Metal Gearmotor w/ 64 CPR Encoder (Helical Pinion)
Features a robust brushed DC motor with a 6.25:1 metal gearbox
Integrated quadrature encoder provides a resolution of 64 counts per revolution
Comes with a 16 mm-long, 6 mm-diameter D-shaped output shaft
The Pololu 24V 37Dx65L mm 6.3:1 Metal Gearmotor w/ 64 CPR Encoder (Helical Pinion) is a robust brushed DC motor, equipped with a 6.25:1 metal gearbox and an integrated quadrature encoder. This encoder provides a resolution of 64 counts per revolution of the motor shaft, equating to 400 counts per revolution of the gearbox’s output shaft. The gearbox is primarily composed of spur gears, however, it incorporates helical gears in the first stage to minimize noise and enhance efficiency. The units come with a 16 mm-long, 6 mm-diameter D-shaped output shaft.
This gearmotor is also available without an encoder. It features a voltage no-load performance stall extrapolation of 24 V 1600 RPM, 100 mA 3.5 kg⋅cm (49 oz⋅in), 3 A. The precise gear ratio is calculated as (25x30) / (10x12) = 6.25/1.
With a diameter of 37 mm (1.46″), this gearmotor is one of the largest and most powerful available.
The gearboxes are primarily composed of spur gears, but they incorporate helical gears in the first stage to reduce noise and improve efficiency. On units with encoders, the encoder portion is safeguarded by a black plastic end cap, which can be easily removed if access to the encoder is required or to slightly reduce the overall gearmotor size.
The gearmotor employs a two-channel Hall effect encoder to sense the rotation of a magnetic disk on a rear protrusion of the motor shaft. The quadrature encoder provides a resolution of 64 counts per revolution of the motor shaft when counting both edges of both channels. To compute the counts per revolution of the gearbox output, the gear ratio is multiplied by 64.
The face plate features six evenly spaced mounting holes around the outer edge, threaded for M3 screws. These mounting holes form a regular hexagon and the centers of neighboring holes are 15.5 mm apart. The 6 mm diameter gearbox output shaft is compatible with the Pololu universal aluminum mounting hub for 6mm shafts. This can be used to mount larger Pololu wheels (80mm- and 90mm-diameter) or custom wheels and mechanisms to the gearmotor’s output shaft.
1x Two-channel Hall effect encoder
1x Magnetic disk on a rear protrusion of the motor shaft
1x Motor/encoder with six color-coded, 8" (20 cm) leads terminated by a 1x6 female header with a 0.1" pitch
37 x 65 mm (D x L)
Shaft diameter: 6 mm
Gear ratio: 6.25:1
Voltage: 24 V
No-load speed at 24V: 1600 rpm
No-load current at 24V: 0.1 A
Stall current at 24V: 3 A
Stall torque at 24V: 3.5 kg·cm
Max output power at 24V: 14 W
Weight: 190 g
Performance at maximum efficiency
Max efficiency at 24V: 53 %
Speed at max efficiency: 1300 rpm
Torque at max efficiency: 0.55 kg·cm
Current at max efficiency: 0.58 A
Output power at max efficiency: 7.4 W
Connections:
1x Red lead for motor power (connects to one motor terminal)
1x Black lead for motor power (connects to the other motor terminal)
If you are not satisfied with a product purchased from the Site, you may request a return within 30 days from the delivery date, unless the product is listed under the Return Exceptions below or is subject to specific return conditions noted on the product page.
This return policy also applies, as a minimum standard, to products sold and fulfilled by third-party vendors through the Marketplace.
Returns under this policy concern non-defective products. In the case of a confirmed manufacturing defect, remedies are handled under the Warranty terms, at the Vendor's discretion. See the Warranty section.
Return Conditions
To qualify for a refund under the 30-day return policy, all of the following conditions must be met:
A valid Return Authorization (RA) number must be obtained prior to returning the product. Returns without an RA number will be refused.
The RA number is valid for 30 days. The returned item must be received within that period.
The RA number must be included with the return.
Products must be returned in unused, unmodified condition (e.g., no scratches, alterations, missing parts, or signs of installation/use) and in their original packaging, suitable for resale.
Shipping fees are non-refundable. Return shipping costs are the responsibility of the customer, except in cases of a product confirmed defective through RobotShop's troubleshooting process or of a verified shipping error by RobotShop.
Refunds are processed within 7 days after receipt and inspection of the returned item.
A $100 cleaning fee may apply to domestic robots returned in used or unclean condition.
A 20% restocking fee may apply to large-quantity returns of items ordered specifically for the customer from the manufacturer or not part of RobotShop's standard inventory.
Return Exceptions
The following products are not eligible for return or refund under this policy:
Used, damaged, or modified products — Items that show signs of use, wear, or alteration, making them unsuitable for resale.
Consumables — Use and wear-and-tear components, altered or depleted through use (e.g., batteries, belts, brushes, gears, filament, tires, disposable bags, lubricants, greases, waxes, etc.). Not eligible for return once opened or used.
Perishables — Goods liable to deteriorate or expire rapidly. Not eligible for return.
Sealed goods (health or hygiene) — Items sealed for health-protection or hygiene reasons (e.g., masks, gloves, odor-absorbing products). Not eligible for return once unsealed.
Build-it-yourself products and items requiring customer assembly — Including robots & kits, robot parts, and other products requiring assembly or soldering. Not eligible for return once assembled, soldered, or installed.
Digital Goods, Software, and Apps — Final sale only, due to licensing restrictions.
Clearance Items — Products identified as clearance or final sale, including end-of-life or discontinued items.
Custom-made, personalized, or special-order items — Products manufactured, configured, adapted, or built to the customer's own specifications and requirements.
On-Demand Items — Standard catalogue products not stocked by RobotShop and ordered specifically to fulfill a customer request.
While the same return policy applies, these orders require a separate contact process for returns.
RobotShop Fulfilled Orders → submit a support ticket from your account under My Support Tickets.
Marketplace Vendor Orders → submit a ticket from your account under My Marketplace Tickets to contact the vendor directly.
Note: Marketplace vendor products are normally labelled with SKUs starting with RM, and identified on the product page with the mention "Sold and fulfilled by [Vendor Name]".
