Plus Pro Edition: Self-Level creeping backwards

[Crowbar]

I tuned the heli this week so it flies nicely and today went ahead and set up the "rescue mode", starting out with the 3D mode (without pitch, just to be safe). When I played around with it on the bench I noticed the swash plate is not level at all when I activate the mode on the transmitter. Un-plugging the battery fixed it and on the next few un-pluggings it was still fine, so I tried it in flight.

First couple of activations in the flight looked fine and I tweaked the gain so it's quick enough without destroying the heli. Noticed it didn't put the heli horizontally but at quite an angle though. Landed and activated it, sure enough, swash had quite a tilt backwards.

Long story short I did some trouble-shooting and it turns out the swash is level when you activate self-level right after connecting the battery. But then it slowly creeps backwards and left, after just a few minutes after powering on, the swash is all the way at the cyclic limit and I have to point the nose of the heli to the sky to center the swashplate again.

The microbeast wiki describes some drift due to vibration and/or temperature differences but the heli had already been out for a couple hours on the bench at the club and it's doing it again and again.

I'll try to do some bench testing tomorrow, I can totally picture the virtual horizon flipping upside down within half an hour so hitting the rescue-button would make it flip 270° and give pitch downward.

Anyone else have a similar problem? I attached a picture of how it looks after about a minute of plugging in the battery and activating self-level.

[Crowbar]

deleted

[panzlflyer]

You are not supposed to activate self level right after turning it on as far as I read, wait for it to do the head pump.
Mine has crept on the bench but is fine in the air.
Mine tilts right as it is trimmed that way as per the manual, moving it will make it somewhat level but sit it on the bench and it slowly tilts right, flies absolutely fine once in the air.

[Crowbar]

Originally Posted by panzlflyer

Mine tilts right as it is trimmed that way as per the manual

You trimmed it to tilt right? Manual doesn't say anything about trimming. I always let the FBL initialize first (in the normal flying mode) before quickly checking rescue mode.

As I rotate the heli, the tilt moves according to where the noise points (like when you test for piro comp during setup). So it can't be fixed via trim.

I noticed it in flight that the heli would level out nicely at the beginning of the flight but get diagonal as time moves on. Which is why I did some more bench tests to figure out what's going on.

[panzlflyer]

In self level mode you can trim it ( the manual calls for 5 degrees of right trim to counter helis natural lean).

In self level mode the swash tries to counter the helis lean in any direction and stays leaning that way.
In normal mode it will lean and then go back to level after a bit .

Parameter A with self level on, use stick to adjust swash for level flight.
Parameter A with self level OFF trims the swash.

You may be better off resetting and doing the setup again as it sometimes fixes issues.

[Crowbar]

Interesting. Didn't see anything about self-level trim in the manuals, gotta take another look. Doesn't appear to be a trim issue though and the heli flipped mostly backwards (tail pointing down, disc towards me) with added left roll. The left roll and back aileron keep getting more and more severe as time goes by.

Here's the video, you can see it moving a lot by skipping through the video:

MicroBeast Plus Pro Edition Self-Level problem (10 min 14 sec)

[panzlflyer]

I would wait for the red/orange light to go out after it does the pitch pump, mine takes a little while.
So I turn on in non self level, it pitch pumps, Blue light then Red will come on and go off. Blue light comes on again, ready to fly.
If you turn on self level, it then goes to Red with Param A flashing, then back to Blue.
It does a sequence that is different to the non plus version and at sometime it must zero the gyros before it is ready, manual is not that clear.

[Crowbar]

Interesting, lemme try that real quick to see if it fixes the problem. I assume I switch it to self level mode and enter parameter A to trim it and move the rudder to reset the trim.

[Crowbar]

Originally Posted by panzlflyer

If you turn on self level, it then goes to Red with Param A flashing, then back to Blue.

Odd, mine is different, it's blue on normal mode, then goes red with the "i" LED lit for 7 seconds before going back to blue with no parameter LEDs lit.

When I switch the flight mode back to normal I get the Red with blinking "a" for 7 seconds, then it goes blue.
My gyro gains are +29% for flying and -95% for rescue (Spektrum values so the range is from -100 to +100, negative values are for rescue mode activation and rescue mode gain).

I can't even get half the back-tilt of the swash corrected by trimming the attitude control horizon. Trimming it backwards from center (blue flashing LED) does nothing as it's already at the cyclic limit. When I point the nose about 50° upwards the swash is level relative to the main shaft but I've had that battery connected for over 10 minutes now.

Edit: 5 minutes later the horizon is about 80° up. I'll leave it connected for a while, just to see if it goes to 90° and still keeps going.

[Crowbar]

After 25 minutes swashplate jumped down suddenly (I got self-level with pitch activated). Swash keeps slowly creeping backwards. So the virtual horizon has flipped 90 degrees and then some. Activating self-level in a upright hover would flip the heli inverted and pitch towards the ground, verified by just holding the heli by the skids and looking at what the swash does. Scary stuff.

Edit:
Virtual horizon seems to be flipping backwards at a constant rate even after a 180° rotation.

[panzlflyer]

Sound like you need to get it swapped out.

[Crowbar]

Yup, I sent it in today, hoping to get it fixed or replaced rather quickly. I'll let you guys know how things turn out.

[vincentwow1450]

Interesting problem. I am also planning to try out the rescue function. One question remaining unclear, maybe you guys can help.

Question: some heli's main shaft leans forward a little, and so as the gyro mounting plate. Do I need to level the heli perfectly horizontal during the auto level setups?

[Frenchdress]

Hi,

no it's not necessary to place it exact level (this would be very hard to do anyway). The device uses accelerometers to determine position in space, so to a certain extent it does "know" in which location it is placed. Only restriction is during power up sequence the heli should be placed level on the ground as usual (not lying sideways or inverted - this issue will be fixed with the next firmware update).

In general it is important to make sure that the device is aligned perfectly to the rotation axis of the helicopter. Otherwise this will mix the 3 axis togehter which particularly will cause bad positioning for the rescue function.

[vincentwow1450]

Originally Posted by Frenchdress

Only restriction is during power up sequence the heli should be placed level on the ground as usual (not lying sideways or inverted - this issue will be fixed with the next firmware update).

Thanks for the reply.
Do you mean that during power up the unit should be parallel to ground/horizontal level, if i want a stable auto leveling?

To make it clear, I draw an ugly drawing to show my concern.

Take goblin 380 for example. The main plate is about 5 degree leaning forward during power up, and so as the BeastX unit. If I power up at that condition, I won't get a very good auto leveling, is that right?

[Frenchdress]

Originally Posted by vincentwow1450

Thanks for the reply.
Do you mean that during power up the unit should be parallel to ground/horizontal level, if i want a stable auto leveling?

To make it clear, I draw an ugly drawing to show my concern.

Take goblin 380 for example. The main plate is about 5 degree leaning forward during power up, and so as the BeastX unit. If I power up at that condition, I won't get a very good auto leveling, is that right?

No sorry, that's not right. As said the system does not have to be perfectly level or parallel. Only it must stand "upright" as usual. If it's tilted forwards or backwards slightly that's not an issue. But some people lay the heli to the side when it's windy, so the heli will not be moved by wind gusts. If you connect your batteries/power up the system when the helis is lying on the side the unit will not initialize the artificial horizon correctly. Hope this makes it clear.

[vincentwow1450]

Originally Posted by Frenchdress

If it's tilted forwards or backwards slightly that's not an issue.

Yes, very clear. Thank you very much.

[Gyropilot]

Originally Posted by Crowbar

Yup, I sent it in today, hoping to get it fixed or replaced rather quickly. I'll let you guys know how things turn out.

Yo Crowbar,

Any update yet?

Thanks,

John

[Sirolf]

I would also like to know what type of finetuning is required to get a good selflevel

[Crowbar]

Ah, just found the latest reply to this in my email inbox.

I only started rebuilding the Logo 550 a couple days ago. Shrink tube malfunction on the Spektrum telemetry y-cable (the one that does main pack voltage) caused most of the wiring to burn up and I was so fed up that I did not touch that heli for half a year and just flew the 700.

Back in the summer I had sent in the Microbeast along with links to my videos and the BeastX checked it out and sent it back, stating there's nothing wrong with it. I was setup very differently so I assume they flew it in a real heli (or HIL test apparatus) to make sure it was all good.

Anyway I installed it a few days ago and the creeping motion was much less. I let it sit around for 10 minutes on self-level mode and the swashplate wasn't nearly as tilted as it used to be. Maybe because I didn't turn up the gain knobs as I used to (I did note all the settings in the setup and parameter menus, not the knobs though ) or maybe they did a software update that fixed that issue.

In general it is important to make sure that the device is aligned perfectly to the rotation axis of the helicopter. Otherwise this will mix the 3 axis togehter which particularly will cause bad positioning for the rescue function

The logo has a wide tray on the back, enough to put an FBL and another small thing right next to it (I guess it's designed to take a VBar with the external sensor) so I put the FBL offset to the right and the TM1100 telemetry module offset to the left. I guess this could confuse the accelerometers a bit since the unit would be accelerated a bit during a (perfect 0 G) roll as the FBL is not exactly on the rotation axis. Then again it's way behind the rotation axis on the elevator axis. I've seen people sticking the Microbeast Plus to the side of the frame (i.e. very off-center) and the rescue function works great for them.

Is there any way to calibrate the self-leveling when powering on? I always turn on the electronics with throttle hold and self-level off, wait for the pitch pump, blue, red, blue light before touching the transmitter again.