I'm looking at Event Logs on various Units, and it seems that the High Vibrations Event (116) occurs only once per takeoff. By that, I mean, if you take off and land, then take off again and land again, you will get the event once for each takeoff. The high vibrations may last longer during each "flight", but the event is recorded only once.
I'm not complaining; I just want confirmation that this is how the firmware works.
TIA,
Paolo
Without having sent any Flight Logs or the Event file for the vibrations you are referring to, it is difficult to understand what you are reporting.
We can only assume that you are referring to the normal vibrations that all models have when the rotor from a standstill starts to accelerate until it reaches the desired rotation speed, and the model starts to lift off the ground.
In this initial phase, mechanical phenomena occur that are not generated by the flight control units but are mechanical phenomena of the model that are seen, felt and recorded by the flight control units.
Due to the gradual acceleration and centrifugal force, the blades begin to align (if the blades are not tightened sufficiently and identically in both blade holders, they could become misaligned with each landing during rotor deceleration) the model begins to lighten and reduce its weight and this reduces the deflection of the skids on which the model rests, as the model begins to lose weight it starts to ‘hop’ on the skids as it changes tilt to the normal tilt it will have in flight due to the thrust of the tail rotor.
If the spindle is twisted, when the blades both start to pull upwards the spindle could rotate inside the head assuming a u-position instead of an n-position and this could cause tracking imbalance causing vibration.
During acceleration from zero to steady state, the model structure passes through all the various resonance points causing the inevitable vibrations.
These are just some of the many things that mechanically cause vibrations at take-off, and they are just the ones that come to mind now. There are dozens of others.
Let us reiterate, however, that they are not caused by the flight control units but are caused by the mechanics of the various models, each one different from the others.
Apologies; I was hoping for a simple reply. I forgot to mention that the high vibrations occurred during flight. I'm familiar with the resonance vibrations during spool-up, and these were not those. I'm attaching the relevant logs (and configuration). In this case, the flights were short. As you'll see, the relevant flight is Flight 12. The high vibrations are found at event times 68 and 404.
I've now had a longer flight and multiple High Vibration Events for the one takeoff. So the question is now moot. However, this does beg the question since it would be bad UI for the Event to trigger continuously, even if the vibrations remain high, it is reasonable to do what the code does and trigger once. But then, obviously, there must be a point where the vibrations have fallen below a certain level and the code can reset to await a new High Vibrations Event. Can you describe how this process works?
I have attached the log files; the configuration remained the same. Details are in Flight 14.
You did not write ‘once for flight.’ but ‘once per takeoff.’Apologies; I was hoping for a simple reply. I forgot to mention that the high vibrations occurred during flight. I'm familiar with the resonance vibrations during spool-up, and these were not those. I'm attaching the relevant logs (and configuration). In this case, the flights were short. As you'll see, the relevant flight is Flight 12. The high vibrations are found at event times 68 and 404.
It is for this simple reason that both we here and on HeliFreak have all been at pains to explain to you what causes the vibrations at each takeoff.
Now that you have posted the flight log file, everything is clearer:
Your model's tail vibrations exceed the maximum threshold and remain above the threshold for the duration of the flights.
Avoid using Auto Level with such high tail vibrations.
It is as you have understood.I've now had a longer flight and multiple High Vibration Events for the one takeoff. So the question is now moot. However, this does beg the question since it would be bad UI for the Event to trigger continuously, even if the vibrations remain high, it is reasonable to do what the code does and trigger once. But then, obviously, there must be a point where the vibrations have fallen below a certain level and the code can reset to await a new High Vibrations Event. Can you describe how this process works?
To avoid filling the event file with the same event repeated twenty times every second, the event is recorded when the threshold is exceeded and reset when it falls below the threshold.
Since during fast manoeuvres it is normal for high vibrations to occur momentarily, the event is only logged if the vibrations exceed the threshold for a sufficient duration of time and is not reset ‘by chance’ but only if the vibrations drop and remain below the threshold for a sufficient duration.
A single event in the user files is sufficient to understand and explain the cause of in-flight breakage of links, uniballs, batteries coming loose in flight, servo horns slipping off servos, mechanical failures and all the other myriad things that some users have experienced due to excessive vibration in their models.
Note: probably due to the high tail vibrations:
we have noticed that data misalignments have occurred in your controller's logs memory. To avoid misalignments in the graphs, we therefore suggest that you reformat them using the ‘Erase Logs mem.’ command.
You did not write ‘once for flight.’ but ‘once per takeoff.’Yes, I was aware of the semantic problem. In Brain2 terms, one can take off and land multiple times per "flight". I struggled to find a term for takeoff and landing within the flight. Any ideas?It is for this simple reason that both we here and on HeliFreak have all been at pains to explain to you what causes the vibrations at each takeoff.
Now that you have posted the flight log file, everything is clearer:
Your model's tail vibrations exceed the maximum threshold and remain above the threshold for the duration of the flights.
Avoid using Auto Level with such high tail vibrations.