Tip Speed / Drive RPM Calculator


Motor kV


Spinning Diameter


Output Pulley Ratio


Motor Pulley Ratio


If you're unsure of your output & motor ratios instead in the same inputs you can enter:

Number of Teeth - output pulley teeth : motor pulley teeth. or

Pulley Diameter - output pulley diameter : motor pulley diameter

Rotational Velocity


Max Tip Speed


Note: this is max theoretical tip speed with a fully charged lipo. Your spinner will spin slower than this in real life.

The UK spinners max theoretical tip speed is 250mph. If you are running a spinning weapon, it is your responsibility to ensure you are below this limit.


Rotation Velocity = max cell charge cell number motor kv / reduction ratio

Reduction Ratio = output pulley / motor pulley

Tip Speed = rpm diameter pi 60/1609344

Tip Speed = rpm circumference rotatations scaling for mph

Thanks to Rory Charlesworth for the inspiration and calculation help.

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