ok to run up motor without a rotor blade load ?

[SkinWalk3r]

I want to test my gear mesh etc. I want to take the head assembly off the mast and just run up the motor(main mast will be on). Is that ok ? or will revving the motor up without a load burn it out ?

[Mr.Andersen]

Acording to the math there should not be a problem to do so.
The RPM of the motor are set bye two factors.

1* Voltage
2* KV rating.

So the motor shold never exeede the rpm desided bye these factors.
Wors case cenario is fore example with a 12S setup and 630KV motor 4,2(max cell viltage) x 12 x 630 = 31752rpm.
In flight there wil be lagg so the rpm of the motor will be less.

The reason it is these way is becouse a brushless motor is in fact a 3~ motor running on 3~squere pulses modulated bye the ESC and the max frequency out of it is desided bye the input woltage.
In other words the ESC regulate the motor bye frequensy.

With that said i have read people got their motors damaged bye running it without load, personaly i think its other reasons fore that but doing it is at youre own risk.

[Anubis328]

Do you even need to run the motor to test the gear mesh? Just spin the head by hand, & make sure it's not too tight (which could kill your motor with or without blades), and make sure it's tight enough that it won't skip.

[hondahirny]

You can do if if you wish. I've done that to test my chinese weight mod where i spooled up and worked the tail linkage by hand. Without the load of the main rotor, you will reach a higher peak RPM, so you might want to back off the throttle 10% or so.