There are a few more variables involved with electric motors in general. Voltage, Amperage, etc. A motor with bigger wire and/or fewer turns in the windings will usually draw more current and produce more torque at a lower voltage. Oppositely, a motor with smaller guage wire and/or more turns in the windings will produce the same torque with less current but at a proportionately higher voltage. In either case, it's a matter of Wattage. Voltage x Amps = Watts.

 

Part 2: motors draw less current at higher rpm. If you load a motor too much so that it runs at lower than optimal speed, (too much blade pitch, adding multi-blade head or bigger blades without increasing gear ratio, etc) it will draw more current, possibly exceeding battery C rating, and/or overheating motor and/or ESC. Oppositely- if rpm tops-out too soon due to too high of gear ratio or some other miscalculated variable, motor rpm will max out per kv rating and rotor will most likely bog-down under load, which means lower gear ratio or possibly higher voltage may be required. Motor Kv rating, voltage, wattage, gear/belt ratios, ESC rating, battery C rating...... all has to be calculated and matched. RTF helis- math usually already done. Kit heli- they usually specify what motor/ESC/battery combination to use, again- math mostly already done. Modifying a heli?- do the math. If I missed anything here, someone correct me please.

 

From what I've read electric motor have maximum torque at 0 rpm and minimum torque at max rpm. I think this is because at 0rpm the potential difference in emf (voltage) is what ever voltage you're running while at max rpm the difference in nothing because the motor acts as a generator and motor at the same time. At max rpm the emf generated by the motor is the same as the emf supplied so the force becomes 0 and torque is just force at a distance so that becomes 0 and the motor stays at that constant rpm.

 

Thanks guys.

But where has is the most power then if you give a very very hard pitch pump? Where would the loss of rpm be the biggest/smallest?

 

Seems to me that optimal motor rpm is near or slightly above 50℅ of maximum unloaded rpm at full battery voltage. If a motor maxes out to 10,000 rpm unloaded at 11.1v, I'd say keep it around 5000 under normal load.

 

Maximum power is reached at about 50% of the max RPM because power is rpm x torque. Running your motor like that though is an easy way to get smokes parts! The castle gov is just not very good so if you want to get more stable headspeed use an external gov or get a kontronik esc.

 

Disclaimer: most of what I know is based on old-school brushed motors and older technology. I'm still in process of getting up to speed on specifics of today's tech. The basic electrical fundamentals still apply though.

 

Ok. Thank you very much guys. Maybe its the governor of my castle and not the rpm or power of my motor.. Align team pilots recommend governor gain of 6 but even on 7 I got that break in. Dont know how far I can go maxbe 10

 

Low gov gain was on the older firmware. Castle gov performs well when loaded continuously. Nick Maxwell proves this to be the case. If an internal gov is set poorly it will show in flight big time...

 

Yes he does.. Tho that said I still did the old castle 4.0v per cell trick and I felt gov was much improved