Pololu 1122 / 1123 120:1 Mini Plastic Gearmotor, Offset 2mm Spline Output
Pololu 1122 / 1123 120:1 Mini Plastic Gearmotor, Offset 2mm Spline Output
Pololu 1122 / 1123 120:1 Mini Plastic Gearmotor, Offset 2mm Spline Output
The Pololu 1122/1123 is a compact 120:1 reduction ratio mini plastic gearmotor featuring an offset 2mm spline output shaft, designed for precision robotics, automation, and embedded systems requiring controlled torque and speed. This gearmotor is widely used by roboticists, hobbyists, and professional engineers developing mobile robots, line-following vehicles, and mechatronic systems where space constraints demand miniaturized drivetrain solutions. It solves the critical challenge of converting high-speed motor output into manageable, high-torque rotation suitable for wheel drives, conveyor mechanisms, and mechanical actuators in compact form factors.
Product Overview
The Pololu 1122/1123 mini plastic gearmotor integrates a 3mm diameter coreless DC motor with a precision plastic gear train that reduces output speed while proportionally increasing torque. The 120:1 gear ratio delivers substantial mechanical advantage, transforming the motor's inherent high RPM characteristics into controlled, predictable rotational force ideal for robotic locomotion and automation applications. The offset 2mm spline output shaft is engineered to interface directly with standard robot wheels, sprockets, and mechanical coupling systems, eliminating the need for additional adapters or shaft modifications in most applications.
This gearmotor's plastic gear construction balances cost-effectiveness with adequate durability for continuous-duty applications up to moderate load conditions. The offset spline design provides superior grip compared to smooth shafts, preventing wheel slip during acceleration and deceleration cycles. The compact cylindrical housing measures approximately 10mm in diameter and 20mm in length, making it ideal for space-constrained platforms such as micro-robots, educational robotics kits, and miniaturized autonomous vehicles where every millimeter of real estate matters.
Key Specifications
| Specification | Details |
| Product Type | Mini Plastic Gearmotor with Offset Spline Output |
| 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 |
| Gear Ratio | 120:1 |
| Motor Type | 3mm Coreless DC Motor |
| Output Shaft | 2mm Offset Spline |
| Operating Voltage | 3V to 6V DC |
| No-Load Speed | Approximately 100 RPM at 6V |
| Stall Torque | Approximately 1.6 kg-cm at 6V |
Key Features
- 120:1 Precision Gear Reduction: Delivers substantial torque multiplication from compact motor core, enabling robot wheels to operate at optimal speeds for controlled movement and obstacle navigation
- Offset 2mm Spline Output Shaft: Provides secure, slip-free mechanical coupling to standard robot wheels and mechanical components without requiring additional fasteners or adapters
- Miniaturized Form Factor: Compact 10mm diameter housing fits seamlessly into space-constrained robot chassis designs, educational platforms, and micro-automation systems
- Plastic Gear Construction: Cost-effective design with adequate durability for continuous-duty educational and hobbyist applications, reducing overall system weight
- Wide Operating Voltage Range: Functions reliably across 3V to 6V DC, compatible with standard battery packs, power supplies, and motor control circuits
- Coreless Motor Core: Eliminates cogging effects and provides smooth, consistent rotational output ideal for precise speed control in closed-loop robotics applications
Applications and Use Cases
- Mobile Robot Platforms: Powers wheel drives in line-following robots, obstacle-avoidance robots, and educational robotics kits where synchronized dual-motor control enables accurate directional movement
- Autonomous Vehicles: Drives wheels in micro-scale autonomous cars and drones requiring lightweight, efficient drivetrain solutions with predictable torque characteristics
- Robotic Arm Actuators: Operates joint mechanisms and gripper actuators in robotic manipulators where controlled speed and high holding torque prevent unintended motion
- Conveyor and Mechanical Systems: Powers conveyor belts, mixing mechanisms, and rotational stages in laboratory automation and small-scale manufacturing equipment
- Educational Robotics Projects: Ideal for STEM learning platforms, robotics competitions, and maker projects where students develop motor control algorithms and mechanical design skills
- Precision Positioning Systems: Enables controlled rotation in camera pan-tilt mechanisms, sensor scanning systems, and mechanical indexing applications requiring smooth, predictable motion
How to Use
To integrate the Pololu 1122/1123 gearmotor into your project, first identify the motor's two connection terminals for positive and negative power supply connections. The offset 2mm spline output shaft should be inserted into your robot wheel hub or mechanical coupling component until fully seated. Secure the wheel using the provided set screw or press-fit mechanism, ensuring the spline engages completely to prevent rotational slippage during operation. Apply power through a motor driver circuit or PWM speed controller, which provides directional control and speed modulation by varying the voltage supplied to the motor terminals.
For dual-motor robot platforms, connect both gearmotors to the same power supply through separate motor driver channels, enabling independent speed control of left and right wheels for steering and navigation. Implement feedback control using optical encoders or current monitoring to achieve synchronized motor speeds and accurate trajectory tracking. Test the gearmotor under no-load conditions first to verify smooth rotation and proper shaft alignment, then gradually increase mechanical load while monitoring for unusual noise or vibration that might indicate misalignment or internal gear damage. For maximum lifespan, avoid stalling the motor under sustained heavy load, as this generates excessive heat in the compact plastic housing.
Frequently Asked Questions
What is the difference between Pololu 1122 and 1123 models?
The Pololu 1122 and 1123 are functionally identical gearmotors with 120:1 gear reduction and 2mm offset spline outputs. The model number difference typically reflects minor manufacturing revisions or packaging variations from Pololu. Both models are fully compatible with the same mechanical interfaces and electrical specifications, so either can be used interchangeably in your robotics projects.
Can I use this gearmotor with a standard 5V power supply?
Yes, the Pololu 1122/1123 operates reliably across 3V to 6V DC, making it fully compatible with standard 5V power supplies from USB adapters, regulated power supplies, or 4xAA battery packs. At 5V, the motor delivers balanced performance with approximately 83 RPM output speed and proportional torque output. For maximum torque output, use 6V operation; for reduced current draw and quieter operation, use 3V or 4.5V supplies.
What type of wheels are compatible with the 2mm offset spline output?
The 2mm offset spline shaft is compatible with Pololu robot wheels, standard hobby robot wheels with 2mm spline hubs, and custom-designed wheel hubs featuring 2mm spline bores. Measure your wheel's center bore diameter and spline tooth profile before purchase to ensure compatibility. If your wheels have smooth 2mm holes instead of splines, you can use a shaft adapter or epoxy the motor shaft directly into the wheel hub as an alternative solution.
How much torque does this gearmotor produce?
The Pololu 1122/1123 produces approximately 1.6 kg-cm of stall torque at 6V operation. This torque is sufficient to drive a 2-3 kilogram robot platform at moderate speeds on level surfaces. For heavier platforms or inclined terrain, consider using dual motors with mechanical load distribution or upgrading to higher-torque gearmotor models. Remember that continuous stalling damages the motor; always ensure your mechanical load remains within the motor's sustainable operating range.
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 1122 / 1123 120:1 Mini Plastic Gearmotor, Offset 2mm Spline Output Online in India
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