Last Updated on January 2, 2024 by Jaxon Mike

Traxxas motors are popular among RC enthusiasts for their speed and power. The 12-turn (12T) motors in particular can reach blazing fast speeds when properly tuned and modified.

This guide will walk you through several methods to extract even more speed and acceleration from the trusty 12T motor.

Understanding 12T Motor Basics

The 12T designation refers to the number of times the motor’s armature windings are coiled around the rotor.

More turns generally equates to higher torque at lower RPMs. Fewer turns (a “low turn” motor) typically generates higher RPMs but less torque. This makes 12T motors a nice middle ground.

Out of the box, 12T motors strike a balance between acceleration and top speed. But there are ways to tweak them for more of either one. Modifying the motor will enhance speed by:

• Reducing system resistance
• Optimizing gearing
• Increasing voltage

Improving these factors allows the motor to spin faster and convert more electrical energy into acceleration and speed.

Reduce System Resistance

System resistance, like friction, impedes the motor’s rotational speed. The motor has to work harder to overcome resistance, diverting energy away from acceleration. Reducing resistance frees up energy to be used productively.

Here are some key ways to reduce system resistance:

Lubricate Components

Friction robs energy through heat and resistance. Lubricating parts like the gears, drivetrain, and axles minimizes friction. Light oil or grease will make the motor’s job easier.

Remove Debris

Buildup of dirt, dust, and other debris increases friction and resistance. Keep the motor housing and gears clean and clear of foreign material.

Replace Old Bearings

Worn out bearings create additional drag. New bearings ensure the armature can spin freely with the least amount of friction.

Change Brush Material

The motor’s brushes transfer power from the battery to the armature. Soft conductive brushes lower resistance compared to the stock brushes.

Decrease Preload

The preload nut that holds the armature can be loosened slightly to reduce friction while still keeping the armature secure. Don’t loosen it too much.

Optimize Gearing

Gearing ratios affect how efficiently motor RPMs are translated into wheel speed. Optimal gearing reduces resistance while providing adequate torque.

Stock gearing tends to prioritize torque over speed. Switching to lower gear ratios will shift the emphasis to higher RPMs and speed. Use the smallest pinion spur gear that still provides acceptable startup torque.

Lighter weight tires and wheels also effectively lower the gear ratio by being easier to accelerate.

Increase Voltage

Raising the voltage adds more electrical energy to spin the motor faster. This directly results in better acceleration, torque, and top-end speed.

Use the highest voltage battery that the motor and electronics can safely handle without overheating. For modified and high-performance 12T motors, that’s typically around 14-18 volts.

Higher voltage also requires more advanced speed controls to effectively deliver the extra power to the motor.

Advanced Modifications

More extensive modifications can unleash the full potential of a 12T motor. These changes alter the internal workings to remove even more resistance and friction while generating greater magnetic field strength.

Armature Balancing

The armature contains the spinning rotor within the motor. Carefully sanding and polishing the armature balances it to allow higher RPMs with less vibration and friction.

Armature Cleaning

Built-up debris inside the armature increases resistance. Meticulously cleaning the armature windings enables unimpeded spinning.

Motor Bearing Mods

High-quality ball bearings minimize friction for faster spins. Ceramic hybrid bearings are lighter and smoother than steel. Or, bushings can be replaced with ball bearings. Just ensure to get the right size match.

Magnet Shimming

“Shimming” entails placing thin shims made of steel or neodymium behind the motor’s magnets. This finely adjusts the magnet position to optimize magnetic field interaction with the armature.

Brush Upgrade

As mentioned previously, softer conductive brushes lessen electrical resistance. Brush material composites like carbon graphite mix also improve conductivity.

Brush Spring Mod

Stiffer brush springs apply more consistent pressure to keep the brushes firmly on the commutator. This enhances electrical energy transfer.

Motor Wind

Rewinding the armature with thinner gauge magnet wire fits more coils into the same space. More windings increase number of turns, improving torque and efficiency.

Be mindful of not exceeding the armature’s physical capacity and causing overheating. Balancing extra windings with gauge size is key.

Turn Counts

For a direct speed boost, replacing the armature with a lower turn unit immediately decreases wind resistance. This reduces torque, however, so ensure your application doesn’t depend heavily on torque.

Commutator Undercutting

The commutator manages energy distribution from the brushes to the armature windings. Undercutting divides the commutator into insulated segments to improve flexible energy delivery to each armature coil.

Ultra Mods

Extreme modifications like removing steel laminations and significantly thinning the armature further reduce weight and resistance but also sacrifice durability.

These mods are best reserved for competition machines and not recommended for everyday bashing.

Supporting Mods

To fully support motor tweaks, other components may need upgrading as well:

Battery

Higher voltage batteries with sufficient amperage provide the extra juice to feed a heavily modified motor. Ensure the battery can supply ample current.

ESC

The electronic speed control regulates power to the motor. A high amperage, low resistance ESC efficiently delivers all available battery power to the optimized motor.

Wires

Thicker diameter battery and motor wires have lower resistance than stock wiring. This prevents power loss over long runs direct from the battery to ESC and motor.

Soldering

Quality, low resistance soldering ensures minimal losses between wiring connections. Avoid cold solder joints which can act as choke points.

Cooling

Higher power motors produce excess heat. Effective cooling keeps operating temperatures in check. Heatsinks, cooling fans, and proper airflow all help.

Tuning and Testing

Once motor mods are complete, proper setup and testing is crucial to ensuring maximum speed and durability. Take the time to properly tune and break-in your enhanced 12T motor.

Gearing Selection

Conservatively start with a higher gear ratio to provide ample torque as you begin testing. Once the motor is broken-in, gradually lower the gearing to take full advantage of the higher RPMs. Monitor temperature closely.

Brush Seating

Run the motor at moderate speeds for short periods to begin evenly seating the brushes against the commutator. This helps maximize electrical contact.

Break-In Process

Gradually increase run times and speeds over several uses. This helps mate surfaces and loosen tight spots. Vary speed during these first runs. Follow any manufacturer break-in guidance.

Data Logging

Logging motor temperature, battery voltage, and speed data during break-in helps tune for optimal operation. Look for trends to identify potential issues.

Temp Monitoring

Use an infrared thermometer or integrated sensor to monitor temperatures. Keep below 170°F (75°C) to avoid potential magnet damage.

Efficiency Testing

Compare temperature versus performance to dial in effective cooling and maximize efficiency. Lower operating temperatures equals less power waste.

Gear Tuning

Experiment with different gear ratios while logging acceleration rates and top speeds to empirically determine the ideal ratio.

Maintenance

Closely inspect the motor internals periodically for wear and debris buildup. Proactive cleaning and replacement of worn parts reduces failures.

FAQs About Enhancing the Speed of a Traxxas 12T Motor

How much voltage can a stock 12T motor handle?

The stock 12T motor is typically safe for up to around 11 volts maximum. Higher voltage risks overheating and premature failure.

Can I run 6S LiPo batteries with a modified 12T motor?

Yes, 6S batteries running around 22 volts are common for heavily modified 12T motors, provided you have sufficiently upgraded ESCs and connectors.

What gearing gives the best balance of speed and acceleration?

Generally, look to gear the lowest ratio that still provides adequate torque off the line, typically in the range of 3.5:1 to 4.2:1 for modified 12T motors.

How often should I replace the brushes on a modified motor?

Inspect the brushes frequently and replace when they are 50-60% worn. More frequent replacement maintains lower resistance.

What fuels work best for cleaning motors?

High purity methanol or isopropyl alcohol work well for cleaning and removing debris from motors. Avoid acetone or fuels containing oil.

Conclusion

Extracting maximum speed from a Traxxas 12T motor requires carefully optimizing internal resistance, gearing, and voltage.

Supporting modifications to the drivetrain are also essential. But methodical tuning and testing is equally important to achieve safe and reliable performance goals. Do your homework before turning your RC speed demon loose!