Formula: Main Blades` RPM (at the 100% throttle)=Max. RPM
÷
(Motor Poles
÷
2)
÷
Drive Gear Ratio
The Main B
lades’ RPM (at the 100% throttle) in the example is: 157*1000÷(10÷2)÷(120÷13)_3400 RPM If the Main Blades’ RPM
needs to remain at 2700RPM during the 3D flight process, then you need to set the throttle
amount (set in the Helicopter “Store
Governor” mode) to 2700÷3400_ 0.8, that is you need to set the throttle amount to 80%. At this time, you need to set the value of the
3D throttle curve (i.e. IDLE1) to 80% (as shown in Figure 2):
So next time, when you fly your helicopter, let it take off in the “Normal” mode first and then switch to the “IDLE1” mode directly, then
your helicopter can starts the 3D flight with 80% throttle amount
(that’s the standardized speed of 2700 RPM).
Notes:
in general, you can set and save 2/3 sets of throttle curve IDLE settings on a high quality transmitter (and you need to adjust
the main blade pitch of each set of IDLE setting as per the actual demand), and switch between these settings during the flight and
have the different throttle amount (set in the Helicopter “Store Governor” mode) to meet the different RPM demands (i.e. when
setting IDLE1 to 70%, IDLE2 to 80%, IDLE3 to 90% in the way as explained earlier, then you will have three different throttle
amounts (set in the Helicopter “Store Governor” mode) to meet different flight demands.
2. In the “Helicopter (Elf Governor)” mode, you are not allowed to check the Max. RPM, so you need to set the transmitter in advance
and check the main blades’ RPM with the help of some external device (like RPM viewer) and then decide the throttle amount you
need to set. Here you can calculate the throttle amount roughly. For example, if the KV rating of the motor is 480KV, the battery is a
12S LiPo, the motor drive gear is 13T and the main drive gear is 110T, then the main
blades’ RPM is: KV Rating × Battery Voltage
÷Drive Gear Ratio (480*12*4.2*13÷110
≈2850). So if you want your motor to rotate at the speed of 2150RPM, then the throttle mount
is: 2150÷2850
≈
0.75 (that is 75%), and then you adjust it accordingly as per your preference or the data you read on the RPM
viewer.
