Calculate rpm under load

[Alexandre]

assuming you have got the correct sized components for the application, under load you got an average of 60-80% of the max rpm to make it simple.

that was my question 4 years ago…

Rpm drop under load, Rm I

i look at my datalogging from my test this w.e. , the foil was up and down all the time for 1 hour, i recordered a average off 28% drop, so in the water under load (not foiling) i have 72% at max off my rpm propeller in the air (from 4300rpm to ±3100) when the battery was discharged at the end , the rpm was not lower as expected by the voltage drop motor not hot, esc around 40°c all the time, battery warm ,swell 3mm i look at airplane forum , 70-80% seems to be a good working number, what do…