Governor setup menu point A
Thus the RPM Governor of MICROBEAST PLUS can be used, the system must be able to detect the motor speed. This is done with the help of a rpm sensor that must be attached to the sensor input of MICROBEAST PLUS. For models with nitro/gas engines usually sensors are used that determine the speed signal magnetically or optically. These sensors are mounted next to the crankshaft or clutch bell and register the number of engine revolutions here. For electric motors the motor speed can be determined electronically. For this purpose a phase sensor (e.g. BXA76013) is connected to one or two of the motor phases. Some electric speed controllers also offer a direct signal output for the rpm signal, so that no additional sensor is required.
To see how the sensor is mounted in detail please refer to the instruction manual from the sensor or from the helicopter. The wire with the rpm signal is connected to sensor input pin at the sideport of MICROBEAST PLUS by using the optional adapter cable BXA76401. This sideboard also powers the sensor with the supply voltage, if necessary. Note that the height of the supply voltage corresponds to your receiver power supply voltage!
Here are some installation and connection examples. As described virtually all kinds of rpm sensors may be used. Unfortunately it is impossible to try and enumerate all types. If in doubt about whether a particular sensor can be used in conjunction with MICROBEAST PLUS ask your dealer to find out.
Electric drive system with external phase sensor
Connect the motor wires of the phase sensor with any two phases of the electric motor. It is recommended to solder those wires to the plugs of the speed controller. So for maintenance purposes it is easier to remove the motor from the model later. In some cases the use of only one phase wire is sufficient. Usually this is the case when the speed controller powers the system with a BEC thus there is no galvanic isolation between motor and receiver circuit. However, we recommend using both wires in any case! This ensures that the sensor provides an interference-free signal as possible.
The electronic speed controller is plugged into the [CH5] output.
Electric drive system with rpm signal output from the speed controller
When a speed controller is used that provides a rpm signal output you can alternatively use the [RPM] sensor input on the front connection board of MICROBEAST PLUS (lowest pin of the tripple signal input). (RPM sensors can‘t be connected here as this pin header does not provide any power supply!)
The speed controller‘s signal input wire is plugged into the output [CH5] as usual.
Combustion drive system (nitro/gas)
Particularly when using sensors for combustion engines check for correct polarity of the sensor power supply on the adapter cable BXA76401. Here commonly sensors are used that are designed for governor systems from other manufacturers and therefore have a special pin assignment. In this case the colors of the connecting cables may not follow the norm (The wire colors of the ALIGN governor sensor HE50H22 are swapped for example. Here red denotes the negative and black the positive pole!).
Sensor function test
At menu point A we check whether the rpm sensor is functioning properly and the rpm sensor wire is connected correctly and in general if there is a usable rpm signal. Watch out! At this menu point the throttle channel is unlocked. This means you have full control over the throttle output [CH5] with your remote control to control the speed controller or throttle servo.
When using an electric model it is necessary to increase the throttle until the motor starts to rotate and the phase sensor or the speed controller outputs a rpm signal. Once the motor is running the Status-LED on the MICROBEAST PLUS should light up in red color.
With a nitro/gas powered helicopter you can simply rotate the clutch or engine crankshaft by hand until the signal generator (magnet or similar) passes the sensor. Whenever the signal generator is within the detection range of the sensor the Status-LED should light up in blue color.
If the Status-LED on the MICROBEAST PLUS does not light up as described please double check the wiring. Particularly pay attention whether the power wires of the sensor are of correct polarity (on some sensors the wire colors do not match the usual standard!). If you have a magnetic sensor check if the magnets are installed with the correct polarity and if they are passing the front of the sensor close enough. Using a crankshaft sensor make sure that the sensor is mounted close enough to the frame accordingly.
In addition to the function control of the sensor, check the throw setting for the throttle servo in the remote control and adjust if necessary: Set the throttle to mid stick position and attach the servo horn, so that the throttle linkage is at a right angle to the servo horn. Then adjust the length of the linkage according to the instructions of the helicopter, so that it also is positioned perpendicular to the linkage lever at the carburetor. Adjust the lever at the carburetor so that it is opened halfways (note the markings on the carburetor!). Now move the throttle stick towards full throttle and adjust the servo travel in the transmitter accordingly, so that the full throttle position is reached without binding. Lastly move both throttle stick and throttle trim on the transmitter to the „motor off“ position and also adjust the servo travel in that direction until the carburetor is fully closed. If the servo travel must be greatly reduced in both directions, it is recommended that the linkage ball on the servo arm is mounted further in so that the servo can be moved over a wider range. For more information refer to the instruction manual for your helicopter.
Also with an electric model, the control range of throttle is crucial. Usually here the throttle endpoints of the transmitter are fixed by an initial programming of the speed controller. But also speed controller exist that require adjusting the servo throw of throttle channel in the transmitter, so that the throttle range is in accordance with the specification of the speed controller. At menu point A there is the possibility to check again whether this setting has been performed correctly. Carefully apply some gas. The motor should start to turn immediately if you move the stick just a little bit and full speed should be reached when the stick just reaches full throttle position. If the engine turns much earlier at the maximum possible speed or only starts to turn at a very high stick deflection decrease the travel of throttle channel in the transmitter or repeat the programming of the speed controller. Thus the RPM Governor of MICROBEAST PLUS can operate correctly, the motor speed should increase as linear as possible when the stick is moved and there should be no ranges in that the motor speed does not change.
Watch Out! Electric motors rotate at high speeds. Keep a safe distance during the function test. We highly recommend to remove the motor from the main gear. However, please observe the manufacturer‘s specifications of the motor. Some motors may not be operated without load. In this case only let the motor run for a short time or let the motor stay attached to the main gear and only remove the main and tail rotor blades (Warning! Increased risk of injury).
If in doubt, do without the function test and throttle stick position check.
When finished briefly push the button to save the configuration and to proceed to Governor setup menu point B.