Frequently Asked Questions

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Setup

Setup menu point J - Adjust left or right or both directions?

You only have to adjust one direction, whether it's left or right, it doesn't matter. Important is to exactly adjust 6° when the blades are aligned on the aileron axis as this teaches the unit the servo throw. Push the aileron stick to adjust the pitch and when the blade pitch is 6° simply push the button briefly and that's it.

Setup menu point J - I don't get blue color at 6 degrees

When getting the 6° too early this shows that you may not use full servo resolution (not using the full throw). This can be solved by using longer blade grip linkage arms, reducing the swashplate inner diameter (shorter linkage balls) or larger swahplate outer diameter (longer linkage balls). Or simply by screwing the linkage balls on the servo horns further in (but this will reduce both cyclic and collective - the cyclic/collective ratio will not change).

Anyhow the color is not a fixed value that is a must to reach. If you get blue you have something similar to 80% usable servo throw. The further you can go the higher the value will be. So everything from blue upwards will give a good resolution and you won't feel any disadvantages. If using good, precise high class servos, strong and with fast speed you even can fly with only red LED without any noticeable difference. Also rotorblades (flybarless blades or not) can make a difference. On a 250 or 450 size heli you should try to get "dark" blue exactly at 6.0° as here servos normaly at not so precise.

You only have to adjust one direction whether left or right, it doesn't matter. Important is to exactly adjust 6° as this teaches the unit the servo throw. And as said the color is of minor importance but you should try to get to blue as close as possible to achieve best performance.

My servos are not on the website's servo list. Can I use them anyway?

The servo list on the website only is a collection of some servos' data. It does not say that if a servo is not on the list that you must not use it. If a servo is not on the list we simply did not test it ourselves or we could not find any data about it. Also we can't know any servo on the market. In fact Microbeast is compatible to nearly any servo on the market. Anyhow when choosing a servo for your flybarless helicopter you should note this:

Servos for flybarless usage

Regarding adjustment of servo parameters read this:

MICROBEAST does not finish initialization. What can I do?

• Watch the running LED lights during the init phase: If the lights A - G light up the sensor's rest positions are beeing calibrated. H - N show determining the RC channels and their center positions. Initially, the chase is from A - N. If a step is done, the light passes only between A - G or H - N. Can one step not be completed, either the unit is not receiving a valid signal or the MB was moved during the process (e.g. due to wind, vibrations, etc..).

• Check whether the receiver sends control signals and that all cables are properly connected to the MICROBEAST. In particular make sure the plugs are inserted with correct polarity and not offset to the pin connectors of the MICROBEAST.

• Only applies to Microbeast with firmware V2.0.0 and up: Is the correct type of receiver selected in the receiver setup menu? See Setup receiver type - Microbeast, Trajectory

The brand new MICROBEAST only shows a red flashing LED or even nothing. What's wrong?

Check very carefully whether all cables are plugged in correctly and all the plugs are connected properly at the correct position (Beast & receiver!). Especially in the vertical direction, not just 2 pins must sit on the header. Also make sure that the polarity is correct on all connections.

Helicopter tips over when trying to take off or tilts to one side in flight.

Please check whether everything works properly on the ground. When giving collective pitch input the swash should move up and down properly. When giving cyclic input it should return to zero after a few seconds. This is also especially after turning on Idle up or switching between flight conditions in the transmitter. Make sure that there are no trims, mixers, etc. in any flight condition and also make sure that the sensor directions for aileron and elevator are setup correctly (Setup menu point M)!

When taking off do not use too much cyclic input. Just let the motor come up to speed and then quickly give pitch input. Only when the helicopter is airborne the system can operate and control commands. If the helicopter sits on the ground, however, a stick input(= command to rotate the heli) would have no effect and the system would increase the cyclic pitch more and more desperately to perform a rotational movement. As soon as the helicopter will get "light" by increasing the collective pitch it will tip over abruptly. So always make sure that the swash is aligned straight during starting procedure!

Tilting in flight: Remove the main rotor blades and let the helicopter run in all speeds on the ground (beware of the rotating parts!). Again the swash should move straight up and down when giving pitch inputs. If at a certain speed it starts to tilt in one direction and this will depend on the rotor speed then that is almost certainly a vibration problem which confuses the sensors in the Microbeast. Trying different adhesive pads might help (smoother or firmer mount) or installing the unit in another location. But especially in the electric helicopter that brings in most cases nothing and there certainly is an error somewhere on the helicopter.

This can be: slightly bent hub of the tail rotor, jammed or defective ball bearings, tail blades / tail rotor is not properly balanced, engine bell not balanced / comes at a certain speed to vibrate or motor bearings damaged making the motor shaft vibrate, slipped ball bearings in the torque tube tail drive system or installed in the wrong position, main gear wobbles / unbalanced; motor shaft bends and runs rough, ... actually everything that rotates on the helicopter can be the cause of such a vibration. On electric helicopter you normaly should not hear, feel or see any mayor vibration (no vibrating tail fin or skids). Then it should normally be possible to attach the Microbeast only with a very thin adhesive pad on electric helis.

On nitro helis the situation can be slightly different as the motors do shake the more or less. This can lead to shaking of the Microbeast unit itself and will make the rotor pane wobble. So here trying different pads or a sandwich made of two pads and a metal plate may help to stabilize the unit better. Also the wiring can be the cause of such a shaking. But when the swash tilts as explained above the cause normaly is some very high frequent (abnormal) vibration and trying around with different kinds of gyro pads only disguises the real cause and may not help 100%.

Is the movement, however, abruptly or suddenly (similar to the twitch in a radio interference) this can especially be caused by static charges from the rear belt. Here a uniform electric potential across the entire helicopter should be done. The use of graphite spray, using a different rear belt or simply changing the belt tension can help.

One could also consider a voltage fluctuation of the receiver power supply. It is necessary that this is stable enough, especially in terms of duration and whether the cable cross-sections and the connecting system are of sufficient size. The power supply should be dimensioned at least twice or three times as strong as expected since very high current peaks can occur in milliseconds which make the voltage sag dangerously low. In this context it may happen that the helicopter flies normally for a few minutes and then suddenly turns or rolls away in flight or even after landing the swash plate turns by itself to one direction. This is a sign that the Microbeast made a quick reboot in flight but because of the severity or duration of power failure it could not completely reload all calibration and sensor data. In this case the cause must be found and rectified and it mustn't/shouldn't be flown anymore since the receiving system was apparently close to a total failure.

(Please do not confuse: A slight tilt of the swash plate when the heli is standing on the ground is absolutely normal when the so-called integrators are not fully discharged. This only will happen after approx. 30 seconds without moving the helicopter or touching the sticks, then the swash returns to its normal position. This also depends on the position of the throttle stick - in the middle position is the discharge at the fastest. A bug in the above named manner is present when the swash moves downright by itself to full-stop also after correcting with the sticks and only cycling power off and on can resolve this problem.)

My servos are getting warm/hot, is this normal?

Similar to a tail gyro a flybarless system is constantly working and correcting. So the servos are moving much more frequently than if ther are controlled manually. Additionaly to that the servos are usually driven with higher frequency to enable the system giving commands to the servos as often and quick as possible. And because of the abolition of mixing levers and the support of the auxiliary rotor plane the servos have to resist higher forces in flight.

This results to a higher power consumption and a stronger heat generation which is usually not critical. However under adverse conditions this can reach a critical range (e.g. at very high air temperatures or even if the servos are installed near other heat sources such as electric motors). In this case try reducing the driving frequency and/or the input voltage.

Servos react somehow "notchy" at high frame rate. Is MICROBEAST damaging my servos?

If the servos are approved by the manufacturer to this driving frequency, this is a normal effect. The servos get new positioning signals four times faster than if they are connected to a conventional remote control receiver. Especially servos with brushless motors run very hard and direct which causes slightly jerky movements in modes with high servo framerate. This is totally harmless to the servos and you will not notice in flight operation.

From MICROBEAST firmware version V2.0.0 onwards a special software filter was installed which slightly mitigates these rough servo movements.

Why do the swashplate servos run very slowly when testing on the bench?

This is absolutely normal. The movement of the stick gives the MICROBEAST only a command to control the helicopter. The sticks do no longer control the servos directly. So you cannot say exactly what the MICROBEAST will do with the servos when you push one of the sticks.

I use servos XY. What are frequency and neutral pulse?

Here you can see a list of collected data: http://www.beastx.com/service_servoliste.html

This list is not intended to be complete or accurate! Please ask the servos manufacturer about his recommandations regarding servo specs and usability in helicopters with flybarless systems.

Neutral impulse: The neutral impulse normaly is 1500-1520µs on any servo. Only special high speed tail servos use a different impulse and are normaly fitted to a specific gyro -> Futaba gyros 760µs -> logitec gyros 960µs.

Microbeast supports all types of different neutral impulses for the tail. On cyclic you will not be able to adjust the pulse.

Talking about frequency: The higher the frequency the faster the control loop will work and the more accurate the system will perform. But also the servos will be more burdened as they get more work to do and the current consumption will greatly increase.

If using a digital servo it definitely should be capable of more than 65Hz. So if we have a unknown servo we carefully increase framerate step by step by testing on the workbench and then fly shortly and check servo temperature very often. If there are no abnormalities like extreme heat production we again increase the framerate and again test carefully.

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