Electric motors can be modified to increase speed by adding voltage and torque by adding current. In the case of a quad-motor go-kart, the focus was on increasing current rather than voltage. The motors of the kart were rated for 2500 watts or around 50 amps at 48 volts, but plans were made to double that current for higher performance. However, overheating became a concern during testing.
### Understanding Motor Components
All motors consist of two main parts: the rotor and the stator. The stator remains stationary while the rotor spins, with the rotor connected to the actual wheel and tire. In hub motors, the stator is connected to a shaft that is attached to the body or suspension of the vehicle. In this particular kart, heavy stainless steel keys were added to secure the motor shaft to the frame. Initial tests revealed issues with the throttle response and steering.
### Testing and Issues
During testing, it became apparent that the throttle was overly sensitive and the steering lacked stability at high speeds. The decision to forego caster in the steering resulted in poor handling characteristics, exacerbated by the lack of suspension sag under load. Additionally, the steering wheel’s connection to the column was insufficient, leading to slipping at high speeds. The power increase also caused motor shaft failures, resulting in twisted wires and damaged components.
### Fixing the Kart
To address these issues, thicker steel keys were used to secure the motor shaft and prevent slippage. Additionally, the nuts connecting components on the kart were tightened, and air was removed from the front tires to improve steering response. A cheap tablet was used to monitor current levels and diagnose regen issues in real-time. These fixes improved the overall stability of the kart but required further attention to prevent future problems.
### Future Improvements
While the kart now performs better, there are still lingering issues such as potential steering column replacement and regen system improvements. Further modifications and enhancements are planned for the kart, with upcoming videos documenting the process for clarity and entertainment. Despite the challenges faced, the journey to optimize the quad-motor go-kart continues with a focus on durability and performance improvements.