Hi,

I'm currently experiencing rather strange behavior on my xl power 550 heli. These symptoms began as I was setting the tail in rate mode (banks enabled) and then turned the banks off by wifi module at the field (triple checked wire polarity).

Heli began to randomly kick tail to the left during pitch pumps, very violently. I then landed and added silicon oil to the belt as I was expecting it to be an static issue (grounded tail). Silicon oil did not fix it so I reverted tail changes back to original but the issue still persisted.

I changed the piro consistency value and tested again but the tail kicking got worse and I could no longer change throttle curve from 72% to 80% or 85% or the violent tail kicks began again. I changed the value back to original but kicking still happened.

I then hovered the heli doing slow pirouettes without using much pitch until I got to my last battery. On last battery the heli began to kick tail to the right and tilt swash to the right at same time. These kicks happened in a series of 2 or 3 kicks and then pause. During the kicking moment I could no longer control the heli and wind was blowing it away. Only during the pause moments I had enough time to bring it closer and land with throttle hold.

After this I tested spooling the helicopter without main blades and changed throttle curve 72% --> 80% and 85% but no errors. I only got it to happen once as I added rapid pitch movement but as soon as I removed the tail blades the issue was gone.

Now I have replaced the tail and belt pulley bearings and one way bearing as well as battery to esc connector. Upon testing it today at the field I could no longer spool the heli up as the violent kicks to the right began on ground. As I hit throttle hold I managed to keep the heli from tipping over, swash was tilted fully to the right. Spectrum analyzer shows max ~26 vibration without blades, bec tests go thru without issues and there is no errors in spirit log.

Have you ever experienced anything like this as I don't have spare motor or esc to test with? Could the issue be in a gyro (Spirit pro) as I have never crashed this heli before (yet ).
Esc Hobbywing 120A
Motor Xl power 4025.
Tail servo Futaba BLS 276.
Swash servos Xl power DS512HV.

I have also been changing the esc P and I values but those are back on default.

Hello,

for me it look like very big static discharges.
There is nothing else that should cause such kicks normally except receiver cable not holding properly.

I recommend to check Flight log for lost frames or signal lost.

In some cases even antistatic spray is not enough. Please make sure belt is not touching anything inside the boom. And that all cables are wired far from grounding wire of the boom.

_________________
Spirit System developer

Hi,

Thank you for your reply! I added an optional belt tensioner and with this I can get the heli back into air but can't change throttle from 72% to 80% (slow increase) or the tail will randomly kick to the right.

Tail belt is as tight as I can pull and multi meter shows connection all the way from tail case to belt pulleys and motor mount.
Spirit logs only show calibration finished and no errors.

Without blades I can change all the throttle curves without any issues and move all the servos normally as well.

Hi
Have you sort this issue out?
I have had the same issue,randomley tailkiks at high rpm.It ended sending the spirit RS back for repair.
//Latjo

Hi, thank you for your answer!

Sadly I have not yet sorted out the issue and I was considering swapping out my spirit pro unit with the spirit 2 unit that I have mounted on my xl 380 or swapping the tail servo.

Since you had the same kind of issue I'm going to try out the unit swapping to see if that could be the reason. Can I just save and import the settings between the units?

Hi
yes i swapp the units between my helis,and the issue follow the unit.
Then it whas 100% clear that the error whas in the unit.It where some error in the circuitboard in unit.
//Latjo

I swapped the spirit pro with an spirit 2 unit. I got the heli about 1m high and there was a rapid tail kick to the left, I hit throttle hold and landed.

Waited for short moment and spooled back up. Before I reached hovering rpm the heli tried to jump up by an rapid positive pitch. So sadly swapping the gyro didn't solve my problem.

I'll try to re route grounding wire next and after that it's going to be rudder servo swap.

Solved the random tail kick and swash movement issue today!

As soon as I removed the spirit s-bus telemetry cable and replaced it with regular servo wire I could change rpm normally and there was no random tail kicks.