Pololu 4780 / 4781 Micro Metal Gearmotor LP 6V - 15:1 gear ratio

The Pololu 4780 / 4781 Micro Metal Gearmotor LP is a compact, high-torque DC motor with an integrated 15:1 gearbox designed for 6V operation, delivering precise speed reduction and increased rotational force in a minimal footprint. Roboticists, embedded systems engineers, and hobbyists use this motor extensively in mobile robots, line-following vehicles, autonomous systems, and precision automation projects where space constraints and consistent torque delivery are critical. This motor solves the fundamental challenge of balancing motor speed with practical torque requirements, eliminating the need for external gearbox assemblies while maintaining reliability and repeatability in demanding applications.

Product Overview

The Pololu 4780 / 4781 Micro Metal Gearmotor LP operates on a brushed DC motor architecture combined with a precision spur gear reduction system that converts high-speed, low-torque motor output into lower-speed, higher-torque output suitable for mechanical load applications. The 15:1 gear ratio provides the optimal balance between speed reduction and torque multiplication, delivering approximately 0.3 kg-cm of torque at the output shaft while maintaining reasonable rotational speeds for wheeled platforms and mechanical systems. The motor shaft features a D-shaped profile with a 3mm diameter, enabling secure coupling with standard robot wheels, encoders, and mechanical assemblies without slippage.

This low-power variant is engineered specifically for battery-powered applications where current draw and thermal efficiency directly impact runtime and system reliability. The integrated gearbox utilizes hardened metal gears with minimal backlash, ensuring smooth power transmission and predictable motion control essential for autonomous navigation and precision positioning tasks. The compact cylindrical housing measures just 10mm in diameter and 20mm in length, making it ideal for space-constrained robotic platforms, miniature vehicles, and integrated mechanical systems where every millimeter of available space must be optimized.

Key Specifications

Specification	Details
Product Type	Brushed DC Micro Metal Gearmotor with Integrated Reduction Gearbox
Brand	Pololu Robotics and Electronics
Origin	Original/Authentic
Warranty	7 days on manufacturing defects
Shipping	1-5 days from Bengaluru
Delivery	7-8 days across India
Support	24/7 via Email and WhatsApp
Operating Voltage	6V DC nominal
Gear Ratio	15:1 spur gear reduction
No-Load Speed	Approximately 200 RPM at 6V
Stall Torque	Approximately 0.3 kg-cm at 6V
Motor Shaft Diameter	3mm D-shaped profile
Dimensions	10mm diameter x 20mm length (motor body)
Weight	Approximately 5 grams

Key Features

• Precision 15:1 gear ratio delivers optimal torque multiplication from compact form factor, enabling reliable wheel drive in small robots and autonomous vehicles without external gearbox complexity
• Brushed DC motor architecture with integrated spur gearbox provides consistent, predictable torque output across the 6V operating range with minimal speed variation under load
• D-shaped 3mm output shaft ensures positive mechanical coupling with standard robot wheels, encoders, and mechanical assemblies, eliminating slippage during high-demand operations
• Ultra-compact cylindrical housing measuring 10mm diameter enables integration into space-constrained robotic platforms, miniature vehicles, and embedded mechanical systems
• Low current draw at no-load operation maximizes battery runtime in portable applications while reducing thermal stress on motor windings for extended operational lifespan
• Hardened metal gears with precision manufacturing minimize backlash and ensure smooth power transmission for accurate position control and repeatable motion

Applications and Use Cases

• Mobile robot wheel drive systems where compact size and consistent torque are essential for line-following robots, obstacle-avoidance platforms, and autonomous navigation vehicles
• Robotic arm and gripper actuation in educational robotics kits and research platforms requiring precise speed control and reliable torque delivery in repetitive mechanical tasks
• Autonomous vehicle propulsion in miniature ground vehicles, tracked platforms, and wheeled exploration robots operating in constrained environments with battery power limitations
• Mechanical automation and precision positioning in laboratory equipment, automated testing rigs, and embedded control systems requiring compact motor solutions with integrated gear reduction
• Encoder coupling applications where the D-shaped shaft provides secure mechanical interface for rotational speed feedback in closed-loop motor control systems

How to Use

To integrate the Pololu 4780 / 4781 Micro Metal Gearmotor into your project, first secure the motor body using the mounting tabs or adhesive backing to your robot chassis or mechanical assembly, ensuring the output shaft extends freely without obstruction. Connect the motor leads (typically red for positive and black for negative) to your motor control circuit through an appropriate motor driver IC such as the L298N, DRV8835, or equivalent, which provides the necessary current amplification and directional control for the 6V DC supply. The motor operates immediately upon voltage application with no additional configuration required, though adding a rotary encoder to the output shaft enables speed feedback for closed-loop control systems.

For optimal performance and longevity, maintain the 6V nominal operating voltage within the range of 4.5V to 9V, with voltage excursions beyond this range potentially causing accelerated brush wear or winding damage. If driving wheels or mechanical loads, ensure the output shaft coupling is secure and balanced to prevent vibration and premature gear wear. For applications requiring variable speed control, use PWM (Pulse Width Modulation) signals at frequencies between 5kHz and 20kHz to modulate the average voltage while maintaining smooth motor operation without audible cogging or efficiency loss.

Frequently Asked Questions

What is the difference between the Pololu 4780 and 4781 micro metal gearmotor models?

The Pololu 4780 and 4781 are functionally equivalent micro metal gearmotors with identical specifications including the 15:1 gear ratio, 6V operating voltage, and output shaft configuration. The model designation difference typically reflects manufacturing batch variations or minor packaging differences, with both units delivering identical performance characteristics. For your application, either model will provide the same torque output, speed performance, and mechanical reliability.

Can I operate this motor at voltages higher than 6V, such as 9V or 12V?

While the motor can tolerate voltages up to approximately 9V without immediate failure, operation above the 6V nominal rating significantly reduces motor lifespan by accelerating brush wear and increasing winding temperature. Operating at 12V will cause rapid deterioration of internal components and potential failure within hours of continuous operation. For voltage flexibility, consider using PWM control at the nominal 6V to achieve variable speed without exceeding safe operating parameters.

What is the maximum load torque this motor can sustain continuously without damage?

The Pololu 4780 / 4781 can sustain approximately 0.2 to 0.25 kg-cm of continuous torque without excessive heating or mechanical stress. Loads exceeding 0.3 kg-cm should be applied only intermittently, as sustained high torque operation generates internal heat that can damage the motor windings and reduce overall lifespan. For applications requiring continuous high torque, consider using multiple motors in parallel or selecting a higher-torque motor variant from Pololu's product line.

Can I add an encoder to this motor for speed feedback and closed-loop control?

Yes, the D-shaped 3mm output shaft is compatible with Pololu magnetic encoders and other standard encoder modules designed for this shaft profile. Mounting an encoder allows you to implement closed-loop speed control, odometry calculations for navigation, and performance monitoring in your robotic application. Ensure the encoder is mechanically secured to prevent slippage and electrically isolated from the motor power supply to avoid noise interference in sensor readings.

When will I receive my order?

Orders are dispatched within 1-5 business days from our Bengaluru warehouse. Delivery takes 7-8 days to most locations across India.

What is your return and warranty policy?

We offer a 7-day return policy on manufacturing defects only. Contact support within 7 days of receipt for free replacement or full refund. Not applicable for user damage or misuse.

Are bulk discounts available?

Yes, wholesale pricing for orders of 10 or more units. Contact our sales team via WhatsApp or email for a customized bulk quote.

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• Returns: 7-day return policy on manufacturing defects only

Buy Pololu 4780 / 4781 Micro Metal Gearmotor LP 6V - 15:1 gear ratio Online in India

Purchase the Pololu 4780 / 4781 Micro Metal Gearmotor LP 6V - 15:1 gear ratio online at The Engineer Store, India's trusted source for genuine electronics. We deliver across Bengaluru, Mumbai, Delhi, Chennai, Hyderabad, Pune, Kolkata, Ahmedabad, Jaipur, and Surat. Get the best price on Pololu 4780 / 4781 Micro Metal Gearmotor LP 6V - 15:1 gear ratio with fast shipping and expert support.

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