Hoverfly Weird!!!!

panino

Member
Hi guys,

Well, I am trying to set autolevel trims for past fiew days withouth sucess.
I lift the hex off in manual, switch to autolevel then trim it out until it stands still in the air. Land in autolevel, disarm, disconect the batt, switch to manual, connect the power back on, liftoff again.
When i switch it to autolevel again the craft will fly ok for fiew minutes and then PITCH FORWARD hard by itself. It gets realy hard to control it at that point with oscilations and instability both in roll and pitch. (there is some PIO i am sure but i managed to land it flawlesly every time). Last landing it even started to yaw hard left, rotating as i was trying to land it.
Also it seems that once set, with the craft hovering nicely, after recycling the power, the trims change in some way. With the same trims that worked fine before, craft pitches forward or aft, needing trimming again.
I am no novice to multis or RC

HF PRO + GPS + EXT MAG (4.8 firmware)
MK 3638 motors
hobbywing 40A OPTO ESC
DX 8 (3.0 firmware) + AR 8000 + TM 1000
quadframe heavy weight hex frame

I wil reflash both boards tonight and redo all the calibrations, but i dont think that is the isue here.

baffled and confused, and in need of HELP!
Vladimir
 

Bartman

Welcome to MultiRotorForums.com!!
Vladimir,
how old are the boards?
did you do a full temperature calibration?
 

panino

Member
Bartman,

Black boards, little less than 2 hours of flight time. Bought them brand new.
I did the temperature, acc and mag calibration as described in the manual an here on multirotor forums.
I did notice a strange thing on HF setup software:
When i connect the board the artificial horisont on the general tab is perfecty leveled, but when i tilt the craft left or right and then level it back the horisont is off usualy to the left by 2 or 3 degrees. Also the altitute indicator jumps up and down by fiew notches all the time.
And that is basicaly what happends in the air i think. I trim the Al almost perfectly (having reduced the trim resolution from 5 to 1), the craft sits there for some time and then gets a mind of its on, and tries to leave. It takes a lott of nerve to settle it back.

Bartman, thnx man, You have also helped me before and I sure apreciate it...
Vladimir
 

Aerovideo

Member
This may or may not help but I've seen my Hoverfly quads get unstable and do some hard yawing when the flight battery is almost dead, it's very disconcerting.
 

panino

Member
Paul,

It could be so, bat alarm on telemetry was set to 14v, as i am using 4s. As i was trying to figure out whats wrong with the trims i may have drained them to a bit lower than 14v. So that might explain the yawing or pitching forward issues but it stil leaves me with artificial horisont not returnin to level on the setup software or the tendency to "forget the trims". Annyway i am in a proces of recalibrating the bird again, so well see. I`ll take Your advice seriously and wil try not to fly under 14v.
Thnx for the input, I am a big fan of Your FPV flying skills and videos, if I may add

Vladimir
 

Bartman

Welcome to MultiRotorForums.com!!
Paul,

It could be so, bat alarm on telemetry was set to 14v, as i am using 4s. As i was trying to figure out whats wrong with the trims i may have drained them to a bit lower than 14v. So that might explain the yawing or pitching forward issues but it stil leaves me with artificial horisont not returnin to level on the setup software or the tendency to "forget the trims". Annyway i am in a proces of recalibrating the bird again, so well see. I`ll take Your advice seriously and wil try not to fly under 14v.
Thnx for the input, I am a big fan of Your FPV flying skills and videos, if I may add

Vladimir

How long ago did you buy the boards?
 

Aerovideo

Member
Paul,

It could be so, bat alarm on telemetry was set to 14v, as i am using 4s. As i was trying to figure out whats wrong with the trims i may have drained them to a bit lower than 14v. So that might explain the yawing or pitching forward issues but it stil leaves me with artificial horisont not returnin to level on the setup software or the tendency to "forget the trims". Annyway i am in a proces of recalibrating the bird again, so well see. I`ll take Your advice seriously and wil try not to fly under 14v.
Thnx for the input, I am a big fan of Your FPV flying skills and videos, if I may add

Vladimir

Vladimir, I hope you figure out your issue. Not sure if the low pack is the problem but I just wanted to mention what I have seen with a low pack and my Pro Boards.

Thanks again, I'm glad you like my videos!
 

panino

Member
Bartman,
I bought the boards brand new 2 years ago. I only got to use them now. I have 3,6 hours of flight time on them (checked last night). Reflashed, recalibrated temp and acc using the bubble lever as recomended.

Just a note for someone who is doing this the first time:
It is important to do temp calibration first and then do the acc calibration. If U do it other way around the artificial horisont will be off no matter how carefuly You do the acc calibration.

The problem of artificial horisont not returning to level when i "shake" the craft around seems to have gone now.
Do I have to recalibrate the mag or can I leave it as is?
Can I do the mag calibration indoor? (my laptop wont connect with my boards for some awkward reason)
I`ll check the operation of the sensor (the setup software is not showing the exact values if U have ext mag, but when You pivot the craft around in yaw axis, the mag readings should change accordingly with the pivoted angle).


Now the only way to check the overall operation of the craft is to fly it. I don`t think I`ll have the time to do it today, and it seems a bit windy so there is no way i could get the AL trimmed.
I sure hope that i got the gremlins out of the bird...

Thnx again for Your help guys ill keep U posted....
Vladimir
 

Bartman

Welcome to MultiRotorForums.com!!
there have been some boards that won't hold calibrations no matter how carefully or accurately you do them. they appear to be normal at the time you calibrate them but once they fly they begin to lose calibration. mine appeared normal both during calibration and during flight in attitude mode. once i selected auto-level though they'd begin to drift and they would get progressively worse until i had to land. i was told it was a small number of boards but i had to send one back for replacement. back on the computer after this happened during a flight, they'd look normal at first but then when you switch on auto-level they'd begin to show an inaccurate horizon.

it seems you have to do the calibrations and then actually fly the helicopter to trigger this problem. back on the computer you can see the issue without having to fly again.

the new board i was sent hasn't had this problem and i'm not sure when exactly the problem boards were made, maybe about a year ago?
 

Bartman

Welcome to MultiRotorForums.com!!
the temperature calibration has to be done very slowly and from a nice cold temperature to start. the heat gun isn't so much to heat the board but to keep the ambient air from cooling it so the calibration can proceed to completion.
 

panino

Member
Bartman,

I have done some trials to test your theory..


When i connect the board to the computer the horizon is perfectly leveled every time.

"Shake" the craft around, and at first horizon gets back to level. Then after few minutes and few shakes the horizon is off to the right by 2-3 degrees.

Switch to autolevel, "shake" it a little (normal pitch and roll angles one would expect while flying), and sure enough horizon is of to the right by 2-3 degrees and aft by 5-6 degrees. After 3 or 4 seconds (the craft sits motionless on the perfectly leveled app complex floor) pitch returns to almost level (aft 2-3 degrees) while tilt stays at 2-3 degrees to the right.

On one occasion pitch was about 10-12 degrees aft and 2-3 degrees to the right!!!!!!! This was the "most" extreme value during the test.

Now i have to say that during the trials i had the horizon returning to level without issues on one or two occasions. But i would not bet my photo gear on that.

Tests were done after reflashing both boards, and after recalibrating both temp and acc.
Temperature calibration was started with "cool" board and a mild temperature from the hair dryer from about 1m (3 ft). It took like 4-5 min to finish, it went really nice and slow.
Acc calibration was done with geat care and constantly checking the surfaces with bubble lever both in X and in Y axis in each position.

Now i am still convincing myself that it is still some weird thing i forgot to, or did not do it right. The thing I would really hate the most is that Bartman is right and i have to return the board to Hoverfly for fix/change.Do the Hoverfly guys know the serial numbers for that bad batch of boards? It would be realy easy to compare the serial no`s and just be sure that that`s it.

Its a bit late now, and my GF is totally annoyed by motors beeping constantly in the living room, so i`ll try and make a video of the test tomorrow morning and then You can check it out and tell me if I am going crazy or I have a drift in the acc.

Thnx for Your help Bartman I REALLY appreciate it
Vladimir
 


panino

Member
According to Ben from Hoverfly the accelerometers on my board are not working correctly. Since i am not the original owner, HF will not change it for the new one. The discount that they have offered is, well, funny..
The board was brand new and I was the first user so i think that the board was faulty at the first place but well, my bad....
So my question is:
Is it possible to change the accelerometers on the board?
If so where can I get them?

thnx in advance
Vladimir
 

Bartman

Welcome to MultiRotorForums.com!!
don't know....Ben probably doesn't know either but Al would. try sending him a PM, his screen name is Photronix

for what it's worth, in a lot of cases electronics are non-returnable. with auto parts especially if you buy an electronic component they won't take it back no matter what you tell them. i can't blame Hoverfly for not wanting to exchange a board that has been out there as long as that one has especially because you're not the original owner. it stinks for you but they've got to draw the line somewhere (sorry if that wasn't what you wanted to hear!).

Bart
 
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