Is there a RPM calculation?

[Bill Brandt]

Been searching here but don't see one.

Example: What is RPM for a 940k inrunner motor on 8s? 33.6*8*940?

Any insight is helpful.

Bill

 

[jack dyer]

Rpm is the kv times voltage 940 x 8s 29.6v = 27,824 unloaded rpm

 

[Bill Brandt]

Rpm is the kv times voltage 940 x 8s 29.6v = 27,824 unloaded rpm

Thank you! Why do you use 3.7 volts? Average voltage per cell?

Bill

 

[Steven Bryant]

3.7 is the nominal voltage of a lipo cell

 

[HTV Boats]

Your peak voltage (8 X 4.2v = 33.6v) will drop as soon as the motor draws current. I have also found the actual rpm on the data logger after a run is about 15%-18% less than the unloaded rpm calculation; volts X kv. Your 27,824 will be in the 23-24000 range.

Mic

 

[Bill Brandt]

Great help everyone!

Thanks,

Bill

 

[darryl whitman]

thanks HTV, this will really help me, darryl