Questions related to the internal Governor function

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This page is a translated version of the page Help:FAQ:Governor and the translation is 100% complete.


RPM Governor - What is this and what does it?

Using the governor function you can simply preset your head speed with the transmitter, i.e. when you like to fly your heli with 2500rpm, you set your throttle curve in idle 1 to straight 62.5% in the TX. Then you just place your heli on the flight field, switch to Idle1 and it'll autonomously will spool up the rotor rpm to 2500rpm. Then you can take off and fly and you will get 2500rpm all over the flight, no matter what load condition the battery is or if your nitro motor will run lean. The governor will try to hold these 2500rpm as good as possible. When rotor head load increases, it'll increase throttle as necessary, when you unload the head and the head speed increases due to aerodynamic force, it'll decrease the throttle automatically. Typically this is a lot better than only controlling the motor with static curves made in the transmitter. And next time, again you will get those 2500rpm when flying the next battery/fuel tank, although this battery might be old and voltage is slightly different or the nitro motor may run more rich or lean.

For electric helicopters the governor function is a good thing if you use an ESC with bad head speed governing capability. Most (cheap) ESC do not have a very good governor or don't feature any governor function at all. For example with some ESC you may get tail pumping at some specific rpm ranges or very abrupt throttle inputs when the load on the rotor head changes. Here you can get good results with the BEASTX governor as besides observing the motor rpm/head speed this will allow to give direct throttle input to cyclic/collective stick input. So it always will be one step ahead compared to a traditional governor function. Using a high priced ESC on the other hand, these typically have so good governor algorithms that it doesn't make any sense to use an external governor. The ESC has much better knowledge of what the motor is doing at the moment, what's the momentary current, voltage, etc. So here the BEASTX governor function probably will not give any performance boost.

So if you are not afraid of the additional wiring and setup procedure using the BEASTX governor can make your heli and your ESC get a very consistent head speed governing at minimum effort, . Of course if you think your ESC is working OK and that the governing is working to your satisfaction, there is no need to use the governor feature.

Especially for the nitro helicopters using the governor functionality of your MICROBEAST PLUS can be very handy as the unit necessary for this is already mounted to your heli. There is no need for an extra device. Just connect a rpm sensor of your choice to the unit and after performing the governor setup procedure you will not have to adjust complicated throttle curves anymore. Just choose the desired head speed you want to fly with and set it up in the transmitter, MICROBEAST PLUS will do the rest including soft start and autorotation bail out feature.

Please note the RPM Governor function can only be used in combination with a single line (single-wire) receiver (Spektrum Satellite, Futaba SBus, SRXL, PPM serial-wire, ...). Using a standard receiver is not possible.


Is the RPM Governor function also available for MICROBEAST (device with silver aluminum housing)

No, unfortunately this features can only be offered for MICROBEAST PLUS and MICROBEAST PLUS HD. For other devices we can't offer such feature due to limitations of the hardware.

Electric RPM Governor - After setting up and enabling the RPM Governor the ESC does not arm anymore when I power up the unit

- Some ESC do not arm when the throttle value in the radio is too close to the motor starting position. When adjusting throttle endpoints at Governor setup menu point B this was intended, so the system does "know" at which point the motor starts and additionally the system can determine the throttle positions of the transmitter. Anyhow if this does not work with your ESC and it won't start there is no other option than increasing the throttle endpoints in the transmitter again (after the positions have been set at Governor menu points B and C!) just until the ESC will initialize. Anyhow MICROBEAST PLUS knows at which point the Motor will start as endpoint have been set before. But note that now the rpm setting will differ from the given table of the MICROBEAST PLUS ProEdition manual, as you stretched the throttle range of the transmitter. So the given percentages may not fit to the desired rpms and the percentage for autorotation bailout mode may change. Use Governor menu point D to check how MICROBEAST interprets your throttle curve values by watching the Status LED color in the different flight phases at menu point D.
- If MICROBEAST PLUS does not get a valid signal from the receiver within 2 seconds it'll lock the throttle and set it to the throttle failsafe position. I.E. this can happen when the receiver does not bind to the transmitter signal immediately when powering up. With some systems this can take a few seconds or this can occur when the transmitter is positioned too close to the receiver. So if the ESC does not arm in this condition probably the throttle failsafe position is not set correctly. Please enter Receiver setup menu and reset the failsafe position at receiver menu point N.

Note: After performing adjustments at Receiver setup menu both the Governor and AttitudeControl will be disabled. So when using one or both of these functions don't forget to enable them again at Parameter menu point L and Setup menu Point N. Especially in respect to the Governor function watch out not to switch on throttle as long as the Governor function is disabled at Setup menu point N. Otherwise the motor will start to run very abruptly when switching to idle up as you have direct motor control from the transmitter.


Nitro RPM Governor - When recovering from an autorotation using the autorotation bail out function the throttle increases up to nearly full throttle and stays there

Nitro helicopters react very sluggish during rpm rampup. Especially when the clutch is worn out it can take a lot of time until the rotor gains full head speed while the motor already runs at full speed, trying to spool up the rotor. This will cause the RPM Governor to stay at full speed as it detects the desired rpm seems to be faster than the helicopter allows. So you need to prevent the throttle from opening completely during spool up by decreasing the Governor quick change rate (Parameter menu point K) to a value that represents the maximum speed the helicopter is able to ramp up the throttle.

How to adjust Parameter menu point I (RPM Governor - Throttle response)

Use menu point I to change the response of the RPM Governor. This determines how fast and hard the system will open or close the throttle when the rotor rpm changes. With ideal throttle response you get a very consistent rotor head speed - the head speed should recover quickly and definite but not hectic when loading and unloading the rotor head.

  • If throttle response is too low the main rotor may speed up immediately in unloaded conditions, e.g. when the helicopter is descending and the RPM Governor will only give soft throttle inputs when the head speed decreases.
  • If the response is set too high on the other hand, the throttle may stutter audible when unloading the motor and/or the motor rpm will kick in very hard and overshoot after the rotor head was loaded and the rpm decreased, causing the tail rotor to turn due to the immediate load change.

The height of throttle response highly depends on factors such as heli size (blade size), motor power and performance and/or the throttle response behavior of the speed controller (when flying an electric heli). If you need to adjust the throttle response, we recommend to start with the lowest value and increase accordingly. Also you should use a lower head speed for adjustment as here you can see the effect more distinct.

Only increase the throttle response stepwise and make sure the throttle will not start to oscillate. Note that with nitro helicopters high throttle response can cause the motor to quit when the throttle is opened too fast. With electric helicopters changing the throttle very fast can cause the speed controller to overheat and especially hard changes from unloaded to loaded conditions can cause incorrect commutations of the ESC (depending on the type of motor) which can damage the ESC if this does not have appropriate protection mechanisms.