Spirit System

Sorry, been to busy to reply in a while. But on Sunday I noticed that some of the servo wires exiting the gyro would touch the canopy. So I pulled the wires down and strapped them to the gyro by putting a wire strip around it. That did give a noticeable improvement, but by no means solved the problem.

I got in 20 flights that day, and every one of them started with level rescue and ended with the rescue being between 30 and 60 degree off.

I have setup my radio to call out the time every minute, and I have gotten into to habit of putting the heli in a hover and test the rescue every time that happens. Then stop trying new maneuvers if it is to crocked.

I realize this is not perfectly safe, but I go to a comfortable height and orientation where I'm pretty confident I will be able to manually recover it no matter what happens when I hit rescue.

The one time I tested it using the spectrum analyzer the aileron axis would sometimes get high enough to emit a warning when it was standing on the skids on my table spooled up to full speed without blades. But when I tilted it up to reduce the ground resonance it would drop down. The two other axis was very low.

Unfortunately the last flight on Sunday ended when a link popped off one of the aileron servos and I crashed. Luckily I got away with only minor damage, and I got it repaired yesterday. Before I fly it again I will try to do a vibration analysis again without blades to see what it looks like now.

I do not have another spirit to test. The helicopter have had one really nasty crash in addition to the one on Sunday. That crash was pretty much a re-kit and it demolished the microbeast that came with the kit. And although rescue always worked flawless on the beast I did not like the arcane setup with a single button and blinking lights. So hence I bought a spirit to replace it. I also replaced everything rotating except the torque tube and the motor. So it was running very smooth. If it can't work on that helicopter, I don't think it can claim to work at all.

Besides, a quick google leads me to believe that this is not something isolated to my unit. There is many reports of this exact behavior from several years back and til now. And rarely does it seems to have been sorted. And then the day after my last flight a friend of mine had his helicopter demolished when a spirit pro drove it into the ground when hitting rescue. So I must say I'm about to loose faith now.

To me rescue have been the best that happened to helicopters since rotor blades, since it allow me to progress so much faster when the fear of trying new things are gone. But with the way my spirit gyro behaves that fear is right back where it was before rescue.

Hi Kurt,

I am not sure how I can answer to your message, since it seems like you are giving up, which is very sad.
We are absolutely convinced that the rescue should work perfectly in any moment. The problem is that helicopters are not simple and all the electronics could interfere in the way we never can't find until we have it here. So for example if you will try exactly same things on our models, I am perfectly sure it will work. We will need at least more details to help you. We have nearly nothing at this moment Please take a photos of your model, unit mounting, cables.
As far as I know the rescue issue was always solved in some way and in 99% cases was caused by the mechanics. Also I have offered you another unit for testing.

If you are comparing rescue with microbeast, it is quite unfair since there was a major crash which will always lead to possible damage. So good comparison is when helicopter is at the same condition. Actually you can find many posts when microbeast, vbar, brain rescue is not performing as good as spirit. I think that these comparisons are not too good since they are usually done after the crash.
I don't know how you are experienced, but from our experience hard crash will leave some damage on the helicopter in nearly any part, sometime also the motor, but more often torque tube. It could take even months to find all damaged parts even that almost everything was replaced. For sensors the worst vibrations are comming always from motor, torque tube and tail. The higher the frequency it could have a bigger impact. So actually vibrations you can feel and see a bent parts are not a problem, since these are usually low frequency.

In any way if you did measurement and the vibration were low in each axis (no spike over 60%) than it was good. Please perform measurement also with tail blades since this can cause difference like day and night. You can post your plots so we can check it.

When you land, did the swashplate return to the center automatically - as when it is after the initialization? If it is maintaining some position, then it could be the issue.

Regarding cables and improvement - it is very important to wire cables correctly. Any cable or anything else should not touch the unit. Cables shouldn't be stripped near the unit.
If changing position of the cables helped you, then this could be area that could be improved on the model. You can also see it mentioned in manuals of other FBL units.

Here you can compare for example with this pilot: https://www.youtube.com/watch?v=lDRzKR5hl8M&t=19s
Do you fly in the similar way or harder? On this video rescue is engaged for several times and precisely also before the end.

Well I don't know if it fits and I can't find reference to it, but I remember having problem on Rescue if unit was not mounted and configured exactly as defined in terms of orientation and in regards to Channel diagnostics. As I remember I messed it up. By inverting Channels and Servos it finally worked on flights but Piro Optimization and Rescue did not. Doing a clean Setup again, following the Wizard Step by Step, the problem was gone. Maybe Tomas can elaborate if this might be an issue.

I'm not giving up quite yet. But I am very frustrated over it. You are right that it might not be a fair comparison though, since the beast was only on there until the first crash.

Unfortunately that crash pulverized the beast, so I can not put it back on and do a fair comparison. But I was not expecting there to be much vibrations since I replaced just about everything that rotate both in the head (main shaft, main gear, swash, feathering shaft, blade grips, and all bearings), and in the tail (gears front and back, tail-rotor shaft, pitch slider, rotor hub) and the stuff that was not replaced looked very fine.

And the spectrum analysis I did right after the rebuild seemed to confirm that. Although there was a bit of vibration in the aileron axis. I can't remember the exact numbers, but I believe it gave a warning some times when standing on the skids. But it went away when I tipped it backward a bit.

I'm quite busy at work now just before vacation, so I have not prioritized trouble shooting. But I did realize that in addition to the torque tube and motor, I did not replace the center hub in the rotor head. So although it looks fine, I have ordered a new one so I will be able to rule that out. It did after all take a good beating since all the forces that went into bending the main shaft must have gone through it. I also have a spare torque tube I can try if the head block don't make a difference.

Like I said I have not given up yet. And I'm really impressed by your dedication to customer support. Offering another unit for testing is just fantastic! I'm going to do some more trouble shooting and get more vibration data before considering going that route, but having it as an option if all else fail is really nice!

Compared to the video you linked, I guess I'm a bit more aggressive both on cyclic and collective. I like quick abrupt movements that makes a bit noise The massive crash I had happened when I "lost sync" while piro flipping and shot out and through a tree. So I'm not doing so much piroing maneuvers just yet since then

Here are some pictures of the installation after I added the wire strip I mentioned:

And here are some picture after I removed it again:
If there is something more specific you want me to take a picture of, let me know.

Thank you for the photos.

We have prepared special firmware which should improve the initialization process little bit.
Difference is that it is checking for temperature difference so in case that there is too hot weather or there is too much current passing through the voltage regulator, it compensate possible drifts.
During the initialization sensor is calibrated and if the calibration is not precise, it will cause a drift (probably not noticeable in the flight) but problematic for the rescue.
Also the problem is, that since the unit is close to the motor it can receive temperature from the motor (especially if you are flying with canopy). But I suspect that the unit will be barely warm even that motor has e.g. 60°C.

In any way it should improve precision of everything. Longer you will leave it with no movement before flying, more precise it should be.

Can you please check this firmware?
http://spirit-system.com/dl/fw//spirit-fw-2.4.20.4df

Thanks for the reply. I have not had time to do much with the heli since your reply. But I did play around with it a bit the weekend before.

Then I set it up for sampling the X-axis on one switch and the Y-axis on another. And it turns out that I had massive Y-axis vibrations in the frequency for the main rotor rpm, and what I at the time concluded was the motor rpm when measuring it in-flight. Much larger than what I saw when measuring it on the bench with only tail rotor blades on.

But now that I look at the snapshots I saved, I believe I was wrong about the second peak being the motor. It seems to be in the frequency range of the tail rotor instead. It is not very easy to extract any data from the PNG's though. Would have been really nice if it had the ability to save the raw data instead and display it in the software later. Would be much easier than trying to decipher everything on a small tablet screen completely washed out by sunlight in the field before unplugging the battery and loosing all the data.

Replacing the head-block and all bearings in the head did reduce the vibrations a little bit, but not much. Still had issues with the bailout. So I replaced the motor as well, but that did not seem to make much of a difference either. I have not had a chance to do any new measurements after the latest changes, so only data I have is from testing the bailout during each flight. And while it might be a bit better it is not that much of a difference.

I will do some more trouble shooting and get some new measurements after the latest changes.

I have not had time to test the 2.4.20 firmware yet. Should I still test with that one? Or are those changes also incorporated in the official release you made since then?

Thank you for the update!

From the plot vibration spike is on the main and tail rotor.
Both spikes are over 100% amplitude which mean it could be even 200% high. They are together with many more along the plot - the small ones that are repeating from the beginning looks to be failing bearing. I dont know if the plot was taken before motor was replaced, but it looks that it could be even bearing from the motor since some spikes are higher than tail rotor RPM. If you want to be sure that it is not the motor, you can just move the motor out of the main gear or remove pinion. Then perform the analysis again on the bench.

I recommend to make the analysis again, with tail blades only - on the ground. This should reduce some spikes on the main rotor, then we will know if it was from the blades itself or it will be still there.

You can say that the model is in good condition if no spike is higher than 60% of amplitude. So it would be good if we can get into this area.

Regarding new firmware - it is 2.4.2 firmware with new calibration procedure. It could help you too, so you can upload it. Please redownload it again if you already downloaded it (the file was updated).

Yes, the spikes seems to be very high. This measurement was done before I replaced the motor. I have not been able to make a new after the replacement.

Before all this I did make a measurement without the main gear installed. So only the motor. And it peaked at about 50% at motor RPM. And when I tested it with the whole drive train engaged with tail blades but without main blades I got one peak at head speed that would sometimes go as high as 70%, still a fairly high motor peak, but not much on the tail. So I was surprised to see the very high tail vibrations in flight.

On the bench there was only 3 spikes and much less random noise in between.

I'm now very curious to do more measurement both on the ground and in flight after the changes I have done. I have not really had time to mess with it, but I have snuck in a bit of wrenching here and there plus the odd flight to test. But not had time to do much analysis. Will report back when I get to look closer at it again.

So regarding firmware, I guess I should download the updated firmware binary you uploaded here plus the new open-tx lua scripts to make the open-tx integration work and have the new features?

I did test the firmware you uploaded here with the 2.4.2 lua scripts for Taranis X9D Plus.

I could not notice any longer init time (but did not time it accurately). And it did not help on the bailout. Neither did it fix the temperature sensor for my Hobbywing Platinum 120A. I still hit 200 degC when pushing it.

I also did not find anywhere to configure the ESC telemetry (like current calibration) or to setup the special functions for the 3 extra channels. Are this still missing for the Taranis? Also the log viewer bugged out on the Taranis. It said it had 640 seconds of log, but all entries beyond about 4:20 was identical and was cycling through all the different error messages.