XAircraft SuperX on heavy lifter

[Jjjkkklll]

Here's the log from today. I was testing out a bunch of new gains, trying to play with everything to see if I could get a reaction. Nothing affected the roll drift left.

I glanced at my OSD monitor for a second and could have sworn I saw the artificial horizon tilted right slightly while it was drifting left. It was a split second, but I'm pretty sure that's what I saw. The IMU is mounted level and secured with 3M tape that I use for all our multis.

Any ideas?

http://log.xaircraft.com/#2015_01_08_175129.000_48.1.06.11

 

[X650Mouse]

M5 and M2 seem to be a bit off to me the other thing, are all your motors level? I don't mean balanced but level to the FC?

X

 

[Jjjkkklll]

M5 and M2 seem to be a bit off to me the other thing, are all your motors level? I don't mean balanced but level to the FC?

X

It's an x8 mounted on 30mm carbon tube with 5degrees of dihedral, so it's incredibly difficult to be precise to a few degrees with the motor leveling. That said, it's very very close. As close as is possible given the setup. I used bubble levels and lasers to get it as level as possible. Even after that, though, I still think one or two may be off by a couple degrees. It's almost impossible to get perfect though.

 

[X650Mouse]

Just trying to help, I have no further ideas

X

 

[Jjjkkklll]

Just trying to help, I have no further ideas

X

I appreciate you trying. I wish it was just that the motors were out of line.

I don't even know where to look though.

It's been a few weeks of not being able to get rid of it now. Considering putting an A2 into it to see what happens. I don't have a spare though so that's another $1600 or whatever with the osd. Really want to work with what we have here so far. Any other ideas would be really appreciated.

 

[Motopreserve]

If you are going for off-angles, you might try a digital angle finder. They can be had for about $30 or less at various machinist retailers.

 

[X650Mouse]

I appreciate you trying. I wish it was just that the motors were out of line.

I don't even know where to look though.

It's been a few weeks of not being able to get rid of it now. Considering putting an A2 into it to see what happens. I don't have a spare though so that's another $1600 or whatever with the osd. Really want to work with what we have here so far. Any other ideas would be really appreciated.

A Segway thought! move the motors around to see if the direction changes and then consider the esc's, a lot of work I know but if you get a directional change you will have accomplished something.

X

 

[Jjjkkklll]

Good idea!

Like you said, though, a ton of work. Plus, I'm pretty suspect of the controller after that glance seeing the artificial horizon tilted right as it drifter left. I'm going to setup my dvr to record so I can see for certain on the next flight.

I'm ordering a digital angle finder now to double check everything.

 

[fltundra]

Motor alignment issues. need to be within 5% in hover.

 

[Jjjkkklll]

Motor alignment issues. need to be within 5% in hover.

Even outside in the wind??

 

[fltundra]

Even outside in the wind??

Then you need to fly it when there's absolutely no wind to get a baseline.

 

[jfro]

SuperX on Flat Hex. KDE 3520. Flights with weights to emulate cam/gimbal.

Why do 1,3,5 (counterclock wise) motors run so much faster...
1st chart is superX with 15" cf props.
2nd chart is miniX with 16 cf props. Everything else is the same.

All ESC's were programed at once with 6 into 1 harness.

Have quad with 3520 KDE and ESC's with SuperX /14" CF props and motor output was pretty much the same.

Any thoughts or is this how Hex's run.View attachment 22676 View attachment 22677

 

[X650Mouse]

In attitude mode the vehicle will try to maintain height when the throttle is at 50% (zero) if there was a wind it would be pushing the vehicle, the only other thing I can suggest is to check that ALL your motors are LEVEL to the FC, not balanced but level.

X

 

[jfro]

In attitude mode the vehicle will try to maintain height when the throttle is at 50% (zero) if there was a wind it would be pushing the vehicle, the only other thing I can suggest is to check that ALL your motors are LEVEL to the FC, not balanced but level.

X

The motors are level to within 1 degree. But since the arms tilt up a bit, level is perpendicular to the arm. It's strange that the the odd motors are all using about the same power and evens are all similar, but use so much less power. I can't logically figure this out. I put the 16 in props on to make sure I had the same pitch on props. I was stretching for an answer. I've used 3 brands of 15", 2 of which are a oem match but the 3rd was bit different, even it said it was 5.5degree pitch. Thought maybe even though they looked the same, maybe the pitch was a bit different.

 

[X650Mouse]

Sorry out of ideas, I don't fly a hexa, but I do know motor levelling is important and if your arms are lifting in flight that is the base line where you should be levelling them, visualise a line through the shaft of the motors all moving vertical upwards, those motors that are not straight up require the FC to adjust to provide a uniform direction for all motors, in your case it may only be two that are out but the whole side is being compensated.

If you suspect the motors or even the esc you can always swap one around and see if it moves the graph..... I doubt it, but fault finding is never easy

X

 

[jfro]

6 motors. It's every other arm that is high and the inbetween that is low. Makes no sense. I measured on the table and will check again. Don't have a clue how I'd check in the air.

 

[jfro]

I took props off and just ran the motors with MR sitting on ground. It appears it's something related to ATT mode. In manual , they all stay relatively the same. Not sure what to think or do at this point.

 

[fltundra]

I took props off and just ran the motors with MR sitting on ground. It appears it's something related to ATT mode. In manual , they all stay relatively the same. Not sure what to think or do at this point.

That's normal.

Most likely your issue is with the frame, motors have to all line up perfectly level. Not even a 1/2 degree in any direction.

 

[jfro]

I just checked again. Perpendicular to the arm, I'm at .2 to .5 on the level .
On the angle with the arm, (tarot pitches em up a bit, they are all right around 6.8 to 7.2)

Cold here today, but low winds so this afternoon I'm going to try some more tests. Work on the gains... If not, then maybe it is the frame. What's a bit non-nonsensical, is how with no props on and it just sitting there, is why when I flip to atti mode, the motor charts change so much....

Todays 1st try. Gains .8 across the board.

 

[fltundra]

I just checked again. Perpendicular to the arm, I'm at .2 to .5 on the level .
On the angle with the arm, (tarot pitches em up a bit, they are all right around 6.8 to 7.2)

Cold here today, but low winds so this afternoon I'm going to try some more tests. Work on the gains... If not, then maybe it is the frame. What's a bit non-nonsensical, is how with no props on and it just sitting there, is why when I flip to atti mode, the motor charts change so much....

Todays 1st try. Gains .8 across the board.

What does the motor log look like when your hovering in gps mode?