For the upcoming Crazyflie 2.1 brushless we developed, together with a leading motor manufacturing brand, a brushless 08028 motor, targeting high quality and high efficiency. The 08 – stator size motors are usually optimized for high power output, to serve the FPV market, but we where aiming for high efficiency. This means fitting maximum amount of copper around the stator, lowering KV, thin stator lamination sheets and high quality dual ball-bearings.

Specification

• Stator size: 08028 (8.4mm x 2.8mm)
• Stator lamination sheets: 0.2mm
• Motor KV: 10000
• Internal resistance: 0.52 Ohm
• Weight: 2.4g
• Dual ball-bearing design, using high quality NSK or NMB brands.
• 1 mm shaft, 5 mm length
• Matching propeller: Bitcraze 55-35mm
• Peak current 1.8A, peak power 7.2W -> 30g thurst @ 4V (using 55-35)
• Rated voltage: 4.2V

Together with the bitcraze 55-35 mm propeller we manage to achieve a system efficiency of over 5 W/g during hover, not to shabby. As a reference, FPV setups normally achieve around 2 W/g. This will bring the hover time for the Crazyflie 2.1 brushless, in the barebone configuration, a bit over 10 minutes.