Hoverboard Wheels - EFeru/hoverboard-firmware-hack-FOC GitHub Wiki

Hoverboard wheels come in many different sizes, printings, tires and power ratings.

Disclaimer: the table below is work in progress and will be updated later.

Picture Size TireType TireSize PowerRating MagnetSize ParallelWires
4.5" Solid ?????? 180W 20 2
6.5" Solid 165x45 200-300W
6.5" Solid 165x45 200-300W
6.5" Solid 165x45 200-300W
6.5" Solid 165x45 200-300W
8" Solid 200x50 200-300W
8.5" Solid 200x90 300W
8.5" Solid 300W
10" Tube 10x2.125 300W
10" Tube 10x2.125 350W
10" Tubeless 70/65-6.5 300W

All have been successfully used with this firmware as the wheel share those same characteristics:

  • 3 phase brushless motor
  • 15 pole pairs
  • Wye/star wiring
  • Hall sensors are 120° apart
  • 4° resolution

⚠️ No Sensorless support ⚠️

Unfortunately the quality of the wheel might differ, over the years the inner design has been modified to cut costs down:

  • different stator and magnet size (20mm,25mm,30mm)
  • different number of coil parallel wires(3,4,5) and thickness

In fact, you can end up with wheels being rated 250W,300W or 350W. Depending on your project you might want to open your wheels and check how it's built, as it can result in less power and overheating.

:toolbox: Troubleshooting

  • Motors are cogging/not running in a smooth way - please try to swap the phases. Usually, color-correct mapping (blue to blue, green to green, yellow to yellow) works fine. However, some hoverboards have a different layout then others, and this might be the reason your motor isn't spinning well. It could also be that a defective mosfet is not turning ON
  • In speed mode, wheels are running at maximum speed - find the right mapping for hall sensors, firmware probably measures a speed with opposite sign
  • With hovercar variant in torque mode, braking actually accelerates - find the right mapping for hall sensors, firmware probably measures a speed with opposite sign
  • If you have a problem on a single motor, try to swap the motors to understand if the problem is coming from the board or the wheel. Some boards have a different phase mapping or current sensing on one the wheels (discussed here )

Using the firmware with other wheels

The firmware might work with other Motors/Wheels if they fulfill following characteristics:

  • The motor must be sensored
  • Hall sensors must be 120° apart

Phases/hall sensor wires might have to be swapped. Check the troubleshooting section above if you have issues. Some motors are designed with hall sensors offsetted compared to the phases to generate phase advance. Those motors will then be faster/smoother when spinning in one direction.

Update n_polepairs parameter in BLDC_controller_data if you have a number of pole pairs different than 15 for accurate RPM/Speed measurement.

Delta wiring

Hoverboard wheels can be rewired from Star to Delta to trade Torque for Speed. This will increase the KV rating by a factor of 1.73 times(√3), but also increase the current consumption by the same factor. It was successfully tested with this firmware in FOC mode, resulting in a speed increase from 640rpms to 1120rpms with no load, so an increase of the Kv rating from 16 to 28, and a 0.39 Ohm phase to phase resistance, on wheels with 30mm magnets and 5 parallel wires.

To be checked : Delta wiring is introducing a 30° phase shift, which will result in a much faster speed in one direction when used with Commutation or Sinusoidal control. FOC compensates the phase shift.

Links

Here are a few interesting builds with hoverboard wheels, you will find many more on Youtube !!!