Some setup confusion

I can assure you that the default value after loading the firmware was 50 Hz. Like I mentioned above, I found that way too low.

I checked the code for 4.0 and 4.1 and the default is 125. Maybe its a controller option that set it slower.

/////////////////////////////////////////////////////////////////////////////////
// TradHeli defaults
if FRAME_CONFIG == HELI_FRAME

define RC_FAST_SPEED 125

define WP_YAW_BEHAVIOR_DEFAULT WP_YAW_BEHAVIOR_LOOK_AHEAD
define THR_MIN_DEFAULT 0
define AUTOTUNE_ENABLED DISABLED
define ACCEL_Z_P 0.30f
endif

//////////////////////////////////////////////////////////////////////////////
// PWM control
// default RC speed in Hz
ifndef RC_FAST_SPEED
define RC_FAST_SPEED 490
endif

Perhaps someone could say something about the vibration amplitude/analysis thing above
? I feel like that is my biggest question mark right now.

Here’s the bin file for anyone to look at.

image

Ugh. I forgot about servo rate. My apologies!! Thanks for showing me that. Ok so I will have to do a little research here. Good news is that the esc is separated from the servos. SERVO_RATE is what sets the esc update rate and RC_SPEED sets the servo update rates. I’m sorry i know that seems confusing. But good news is that you can set RC_SPEED to 250 to get the better update rate for your servos

Ok, I see :slightly_smiling_face:

I was a little confused as I thought we were talking about the same parameter, I now realised that RC_SPEED is another one.

So, I finally found the answer:

That info would be useful to have in the docs, instead of that strange “or” wording (like I could choose whatever)
https://ardupilot.org/copter/docs/common-sensor-offset-compensation.html

Back to this again…

I had the tail balanced professionally hoping that the vibrations would go down, but I’m not sure if it made any difference at all. This is what it currently looks like:



Is it safe to continue the tuning process or do I need to bring the levels down?

Next question. The documentation says that I should “achieve a solid tail”. How “solid” can I expect it to get to? I currently have ATC_RAT_YAW_P set to 0.265. When moving the stick, the initial response is very quick (almost a little too sensitive) but there is a slight side to side “bounce” when releasing it.

And last, at what point is it safe to try out the acro mode? the documentation prompts me to only use the stab mode. I’m not really comfortable with the stab mode as it feels like I’m constantly working against the aircraft.

I use that mode for FPV and it is safe to fly as long as you have experience in flying rc helicopters without any self leveling augmentation. I recomend to disable the acro_trainer feature. Which heli is it? Depending on the flight style you want to perform there are some parameters you can play around to get the feeling you want.

Usually, with every other flight controller I have/had, I just use the normal “unstabilised” mode as the starting point for every flight. Then I switch on or off a GPS mode when I see it fit. I would prefer to use arducopter in the same way, if possible.

I don’t see the point of these in-between stab modes where the aircraft moves without stick inputs while constantly drifting… (Naza had it too)

I tried the acro mode for a bit, but it felt very flimsy and sloppy compared to what I’m used to. Not sure what acro trainer was supposed to do, but it was disabled early on.

It’s an msh protos which I guess is considered outdated by now.

Is there really no one here that can tell if my previously posted vibration levels are unacceptable?
I’m thinking that I need to finish that step before moving on to others.
The documentation doesn’t help here, as it shows something very different than what I’m getting in my logs. :person_shrugging:

log_11.bin.gz

@kitchen_faucet Windows prompt me not to open the log file you shared, do you have google drive?

First of all, Acro needs your rate controller tuned at the best and then there are few parameters you can change to adjust the feeling to your needs.

Reduce the vibration levels bellow 12 or so.
Use stabalize mode for “manual” flights. use “loiter” mode for GPS assisted flights.
Read the docs to get the full performance of your vehicle.

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The Z axis vibes are way above 12, I don’t really think it is possible to get that low:


Regarding stab mode, it makes the aircraft want to drift away and then requires constant stick-pushing, not so optimal.

The docs haven’t been able to answer my specific questions, and also, overall they are just too overwhelming and confusing for normal people like me. I didn’t come here to study advanced uav engineering or development (or whatever the docs are intended for), I just need to solve the problems that prevents me from operating this drone.

I’ve been battling with this ‘project’ since late 2019 and am still not able to just go and use it, it is getting kind of frustrating at this point… perhaps it’s time to move on to another flight controller that just works.

Post a link to this .bin log file.

2023-02-28_16-11-00.bin

You are approaching the problem with the wrong attitude. You can switch to another flight controller or to other firmware but none will work properly until you fix the root of the problem: vibrations.

And yes, you will need to spend time and effort reading the documentation. That is the way this works. You do not need a degree to read it on understand it, tons of users do not have degrees.

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Before trying this pixhawk/arducopter combo, I had 2 other flight controllers and I did not have any vibration problems with them. So it’s obviously a flight controller or software problem. I have had both the motor and tail checked by professional balancing equipment and they are good.

There is no reason for me to go extra lengths to get to the goal. If I “need” go read a book to get going then this isn’t just ready for the masses yet.

The only option left for me seems to be the fly wing H1.


You could perhaps post some more details/pictures of your mechanical setup. Looking at vibe logs without having the perspective view of how things have been built /assembled doesn’t help much in solving the problem.

Being a ‘normal person’ I’ve found the documentation (and this forum) to be very helpful – once I’ve found the right search term to locate the subject I want :roll_eyes:

A while back I had a Z-axis vibration problem with one of my TRex 500 helis, even though I’d balanced everything that moved. The solution that worked for me was to mount the FC with 5mm Kyosho vibration eliminating tape and then stick a piece of lead on top of the FC case as a damper. I can’t remember what number I achieved, but it was well below the 30-mark recommended in the wiki.

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