SPIDER Automation | 48P 21T Steel Pinion Gear | 3.17mm Bore for 1/10 Scale RC Cars
Product Overview
The 48P 21T Steel Pinion Gear is a motor-drive gear designed for compatible radio-controlled car transmissions, particularly 1/10 scale RC vehicle applications. It transfers rotational motion from the motor shaft to the mating spur gear, forming an important part of the vehicle’s drivetrain.
This pinion features a 48P gear profile, a 21-tooth configuration and a 3.17mm mounting bore. These specifications help determine compatibility with the vehicle’s spur gear and motor shaft. The supplier also identifies compatibility with a 2.7mm motor shaft; the actual mounting arrangement must account for the difference between the stated shaft diameter and bore diameter.
Its metal construction and compact form make it suitable for RC drivetrain assembly, replacement and gearing adjustments. Selecting the correct pinion requires matching the gear pitch, tooth count requirements, shaft interface and available mounting or retention arrangement.
Technical Features & Functional Characteristics
- 48P Gear Specification: Designed to mesh with compatible 48-pitch spur gears. The mating gear must use the same pitch standard for correct engagement.
- 21-Tooth Pinion: Provides a 21T motor gear option for selecting a suitable transmission ratio in an RC drivetrain.
- 3.17mm Bore: Features a 3.17mm internal bore for a compatible motor shaft and mounting arrangement.
- Metal Construction: Made from metal for use in motor-driven gear transmission systems.
- Black Finish: Supplied in black for a consistent appearance within an RC drivetrain assembly.
- Compact Form Factor: Suitable for space-constrained motor and transmission layouts in compatible RC cars.
- Gearing Adjustment: Changing pinion tooth count can alter the motor-to-spur gear ratio, affecting the relationship between motor speed and wheel-side torque.
Gear Ratio & Drivetrain Function
The pinion gear is mounted on the motor shaft and meshes with a larger spur gear in the RC vehicle transmission. The relationship between the two tooth counts determines the basic gear reduction ratio.
For a 21-tooth pinion, the basic gear ratio is calculated by dividing the mating spur gear’s tooth count by 21. A larger spur gear relative to the pinion produces greater gear reduction, while a smaller ratio generally allows higher drivetrain speed at the expense of mechanical torque multiplication.
The final gearing choice should also account for motor characteristics, vehicle weight, tyre size, operating temperature and the manufacturer’s recommended gearing range.
Applications
- 1/10 Scale RC Cars: For compatible motor-drive gear assemblies in 1/10 scale radio-controlled vehicles.
- RC Car Gear Replacement: For replacing a worn or damaged pinion when the gear pitch, bore and tooth count are compatible.
- 48P Spur Gear Drivetrains: For transmissions using a matching 48-pitch spur gear.
- RC Gearing Adjustments: For changing the motor-to-spur gear ratio to suit a particular vehicle setup.
- RC Motor Upgrades: For compatible motor installations requiring a 21T pinion with the appropriate shaft interface.
- Model Vehicle Assembly: For building or servicing compatible small-scale electric model vehicle transmissions.
- RC Workshop Maintenance: For drivetrain refurbishment and replacement of compatible motor pinion gears.
- Custom RC Projects: For custom gear-driven model vehicle systems designed around a matching 48P gear profile.
Package Includes
| Quantity | Component |
|---|---|
| 1 | 48P 21T Steel Pinion Gear with 3.17mm Bore |
Product Specifications
| Parameter | Specification |
|---|---|
| Product Category | RC Vehicle Drivetrain Component |
| Item Type | Motor Pinion Gear |
| Gear Pitch | 48P (48 Pitch) |
| Number of Teeth | 21T |
| Bore Diameter | 3.17mm |
| Motor Shaft Compatibility | 2.7mm shaft diameter stated in the product description; mounting arrangement must accommodate the 3.17mm bore |
| Material | Metal (steel identified in package description) |
| Colour | Black |
| Intended Vehicle Scale | 1/10 scale RC cars |
| Mating Gear Compatibility | Compatible 48P spur gear |
| Package Quantity | 1 pinion gear |
Installation & Operating Recommendations
Install the pinion gear on a compatible motor shaft and align it correctly with the mating spur gear. Correct gear pitch, shaft fitment and gear mesh are essential for smooth transmission and reduced wear.
- Match Gear Pitch: Use only with a mating spur gear designed for the same 48P pitch standard.
- Check Shaft Compatibility: The stated 3.17mm bore and 2.7mm motor shaft dimensions differ. Confirm the intended shaft fit and retention arrangement before installation; do not force the gear onto an undersized shaft.
- Set Gear Mesh: Adjust the pinion-to-spur gear engagement to avoid excessive tightness or unnecessary clearance.
- Secure the Pinion: Use a suitable retention method compatible with the gear and motor shaft. Do not assume a set screw is included.
- Check Gear Alignment: Keep the pinion and spur gear in the same alignment plane to reduce uneven tooth loading.
- Select Gearing Carefully: Consider the spur gear tooth count, motor speed, vehicle load and temperature when choosing the final gear ratio.
- Test at Low Speed: Run the drivetrain initially at low speed and check for abnormal noise, vibration or binding.
- Inspect for Wear: Periodically inspect the gear teeth and mating spur gear for wear or damage.
