12mm OD 500 Series (Proton) brushless motors operate in the 50 to 100 watt range. 500 series motors excel at high RPM (80,000 RPM max) applications.

  • Inrunner construction
  • High speed operation – 100,000 RPM
  • 4 poles / 6 slots
  • 1.5mm or 2mm shaft


May be mated with P16 gearboxes for very high power-to-weight drives.

Neumotors brushless motors can be assembled in the USA from domestically manufactured components. Please call for details.

0507: 50+ watt class motors

Motor RPMs
per Volt
Rm (Ohms) Io
507/3200 3200 0.50 0.20 2.99 0.423 31 3
507/4000 4000 0.30 0.30 2.392 0.339 25 4
507/5300 5300 0.18 0.40 1.805 0.256 19 5
507/7300 7300 0.10 0.70 1.311 0.186 14 7
507/8300 8300 0.09 0.80 1.153 0.163 12 8
507/11,000 11000 0.05 1.40 0.87 0.123 9 11



The motor sizes and KVs listed above are the most common for this particular motor range. Custom sizes and  KV (RPMs per volt) are usually available.  Please contact us for more details if you don't immediately see the solution you are seeking in the tables above.

KV is the term used in the brushless motor workspace to specify the number of rotations per minute that a motor will turn for each volt applied to the motor/ESC with no load on the motor.

Neutronics specifications are +/- 5%.

For a more complete discussion of KV, please go to our KV FAQ page.  


  • Continuous rating is the power the motor can deliver while maintaining the external housing temperatures below 100C.
  • MAX power is achieved at max RPMs and voltage, not at a partial throttle or reduced voltage.
  • MAX power rating is the power the motor can deliver beginning with motor at a temp of 20C until it reaches it's limit temperature of 100C.
  • The ratings are therefore dependent on a number of variables including air flow, ambient air temperature, contact cooling etc. Each application will present different variables.  


When used within the constraints described above, BLDC motors' primary "wear" item(s) are the bearings supporting the shaft. Bearing life is inversely affected by speed, temperature, and radial and axial loads.  While an MTBF figure can be generated, it would be rendered invalid by excursions beyond prescribed temperatures or load limits - such as prop strikes, or side loads.  MTBF must be determined on a case by case basis, and even then, it would be subject to numerous exceptions.


Limited by kv (RPMs per volt) times the applied voltage.  Max voltage must be kept below the voltage which will spin the motor over max rpm for the motor series.


See power ratings above.


  • Winding temperature:  -- 180C
  • Magnet grade: - 180C UH grade
  • Bearings:  Japanese SPB bearings


  • APD controllers automatically adjust timing for optimum efficiency
  • Recommend low timing for controllers that require configuration

Pole Count vs. Pole Pairs

  • Neumotors lists the number of poles in a motor rotor. Example: N S N S would be a four pole motor.
  • Some ESC manufacturers use the term "pole pairs" which refers to the number of N and S pairs.  Example: N S N S would be a 2 pole pair motor.