Tricopter/KK2.0 Motor Issue

[RotateB4TheEnd]

Hey all,

I'm having an issue with my newly assembled batbone tri. I'm using a KK2.0 board.

When doing some throttle ups with the entire system powered up, I'm having an odd issue.

Whichever motor is plugged into the M1 slot (This is normally the front left motor) will continue to rev up to a higher and higher rpm if the throttle is held at a low setting. In addition, whichever motor is plugged into the tail motor slot (M3) will require the throttle to be pegged to get it started and then it proceeds to slow down and eventually stop even though the throttle is set at the same setting.

Any thoughts on this?

Thanks,
Jake

 

[xuzme720]

Sounds like the accelerometers think the tri is not level and is correcting for that...
Try recalibrating making sure the tri is level and keep it level while doing the throttle up tests...

 

[RotateB4TheEnd]

I've recalibrated it a couple of times and still have the problem when the craft is sitting level.

Maybe i've got a bad solder joint or something.

 

[cranialrectosis]

Did you calibrate/synch the ESCs?

 

[RotateB4TheEnd]

I calibrated them through the KK2, i don't have a USB programmer.

Again the puzzling thing is that I can swap the motor 1 and 2 connectors on the KK2 board, but the motor that acts up is always the one plugged into the M1 slot.

 

[Craftydan]

Is this happening with Self level on or off?

 

[RotateB4TheEnd]

I had it on at first and then turned it off and still had the same issue.

 

[Craftydan]

double checked motor/prop directions? left and rear CW, right CCW?

shock isolated your KK2?

Have you been able to pop it up into a hover?

This really does sound like the control loops are fighting to maintain attitude but getting confused, but if it's still on the ground it might just be getting lost. . .

If all that's still good, try clearing your "I" gains. It'll have a hard time maintaining attitude (drifts back to level) with them at 0, but at least all your gyro corrections will be instantaneous (without any cumulative effects). If that fixes the problems, bring down the I limit to 1/2 and slowly creep the I gain back up.

 

[Tritium]

How is the balance on that prop?

Thurmond

 

[xuzme720]

With the issue following the board (staying on M1), I'd say Dan and Thurmond are on the right track. Make sure that your props are well balanced and you don't have vibe messing the acc/gyro's up and then try Dan's gain adjustments.

 

[RotateB4TheEnd]

I'll see if I can get it up into a short hover in the morning.

In terms of props and vibrations, I was running the motor with the prop very loosely attached. I just wanted to see if I could throttle them up without taking flight inside my house, so the props were pretty much freewheeling. My KK2 is mounted inside it's foam shipping case and then that is mounted to the frame with double sided sticky foam, so I feel like that should isolate the vibrations pretty well.

I'll try turning down the I gains when I do the hover test. However, with the left front motor spooling up excessively and the tail motor not always spinning I'm not sure I'll make it off the ground correctly.

 

[Craftydan]

No!

Crank down the props, check directions, and get her in the air!

leave everything default till you've done that. Tri's are *Notorious* for acing weird on the ground, but flying fine once the craft is in the air. It's just too easy for the control loops to get confused when they make corrections, but the gyros/accelerometers don't change. Pop her up into a hover, and once she's free of the earth, you'll have a better view of how tuned she is. Leave the SL on for now if this is your first multi -- turn it off when you start to tune.

. . . but do it outside from some distance

 

[Tritium]

Props off or props tightly attached. Anything in between should NEVER be!

Thurmond

 

[kah00na]

Also double check that you have the tricopter layout on your flight board and that you are connecting your ESC's to the proper connections on your flight board... I had some switched around last time and it took a while for me to figure it out.

 

[Hionimi]

When you 'Arm' the controller, is it on a level surface? Because I believe the gyros are set to 0 when arming.

 

[cranialrectosis]

Dan is right.

So is Thurmond.

The only thing I want to add to those posts is this. Shoot video of your maiden flight. If you have a build problem that makes your copter un-flyable and you crash it, you can post the video here and we can try to help you solve problems to get you in the air. If you shoot video and you crash, the crash is less likely to be wasted.

 

[Craftydan]

When you 'Arm' the controller, is it on a level surface? Because I believe the gyros are set to 0 when arming.

Gyros don't care which way is up, so yes, arm while stationary so they get a good calibration, but it doesn't have to be level.

The accelerometers, however, do need a level surface to cal properly, but on the KK2, it's a manual calibration run from a menu option. Self-level will always seek the calibrated level so make sure the props are level to gravity if you plan to make use of SL. The Accelerometer cal needs to be done once before maiden, but it's personal taste when it needs to be done again, if ever.

 

[RotateB4TheEnd]

Sorry for the lack of responses. I headed back down to college and didn't bring the tri with me. I'll be back home for a quick visit at the beginning of February, so hopefully the weather will cooperate then.

 

[RotateB4TheEnd]

After flashing my KK2 to 1.6, I am getting a "not ok" reading on my x gyro. From what i've researched, there isn't really a way to fix this. Does anyone have any thoughts or experience with correcting this problem? I've tried a board reset already

 

[Craftydan]

on the test screen when you rotate the frame around X, does the gyro X number change? The sensor might be dead