Dragonfly Multi-rotor issues

[fragdrum]

I have built a dragonfly multi rotor from the electrohub kit. Im using the emax motors from the powerpack in the store, 30A fire red series Simon K ESC from readytoflyquads.com, emax 3154 servo, and for my FC a flip 32+. I am currently using 10x4.5 props. I have calibrated the ESC's together already. My FC has been set to tricopter mode and my PID programming is at 0.
When I try and fly, I have to put the throttle past 50% in order for the tail motor to turn. It has only flown twice and that was with the default preflashed PID settings from readytofly but it was very unstable due to being set for an X quad. I set my PID settings down to 0 so I could start fresh, and now it wont even take off the ground. It will flip over backwards or flip forwards if I give it a little forward pitch. All of my sensors have been calibrated.
Please shed some light for me.

 

[RichB]

Why did you set your PIDs to 0?

What flight mode are you using?

How is your transmitter setup?

 

[fragdrum]

I thought it would be quicker to tune if I start at 0 since they set it from the factory for a quad. Im using auto level and manual modes.
Not sure what your wanting to know with transmitter setup.

 

[jaysteel]

I started tweaking with my P at 1 on Pitch, Roll and Yaw. So far I'm up to 8 for Pitch and roll and .050 for the I on Pitch and Roll. The pitch and roll seem really stable.

The only problem I'm having now is my Yaw. I have the P at 3.5 and the I at .075. It seems to fly well but when i yaw right, it wobbles back a little. This is while in a hover. Yaw left doesn't seem to have the issue. I know it's being caused by the swingback of the tail to stop the movement, but I don't know how to correct it. I have my Expos set at -40% on the transmitter

I'm using a Naze32 with Cleanflight. The same emax motors in the FT kit and 25A EMax BLHeli ESCs (They were cheaper than the 20A) and the electro hub. I've gone through many 1/2" booms since the original ones that came in the kit. HomeDepot is making some good money from me buying 1/2" square rods. At least now I have some landing gear that keeps me about 6" off the ground. The plastic ones from the kit are too short, especially if you have to take off and land in grass.

 

[CrashRecovery]

That swing you talk about is a known issue in cleanflight and is being looked into as we speak. Eric has been ranting about it.

 

[fragdrum]

Alright so I went back to my default PID settings and now the multirotor will lift off nice and smooth.
I now have a new issue with it... As soon as it breaks free of the ground, it will start to spin clockwise. If I try and correct it, it will start to tip and start spinning counter clockwise. Thinking that I had a stripped servo horn, I switched them out and I still have the same issue.

 

[BanditJacksRC]

make sure your rudder gyro is set to the right direction. When the batt is plugged in hold the copter in you hand and swing the tail to the left, and the motor should move to the right. Swing the tail to the left and the motor should move to the right. If you're finding the motor is swaying in the same direction that you are moving the tail, go to the sero tab and reverse it (not in your radio)

 

[BanditJacksRC]

also which way are your props spinning. On my tri i have the tail and right props spinning clockwise, and the right arm spinning counterclockwise. With this setup I have to have my tail motor installed slightly slanted to the left (when looking at it from the top).

This will help offset any spinning you are experiencing right away.

 

[fragdrum]

My left arms are spinning clockwise, right arms counter, and tail counter. It has flown fine before until I set my PID settings to zero from what came set from the factory. When I did that, it wouldnt even take off the ground. Now I have set it back to what they had it as and now it just spins when leaving the ground.

 

[BanditJacksRC]

Yeah I messed my post up, my props are left and tail cw, right ccw, so just our tails are spinning opposite or each other. so I have a slight left tilt, maybe yours needs a bit right.

the fact that it was flying okay before you played with the pids, and now its not is pretty strange.

You might be on the right track with a stripped horn.
You could pull apart the tilt, take the horn out and see if there is any slop/play. If if came with extras make a new one. see if that helps.

 

[fragdrum]

I have replaced the horn already but there is a slight crack in the servo case.

 

[BanditJacksRC]

it still spins with the new horn?

With the new horn, when you manually move the motor back and forth, it should be nice and smooth without any play. A tiny bit should be okay, but anthing more than a few degrees might be a bad servo and causing this issue.

IDK tho man its pretty strange to me. hopefully someone else can help troubleshoot, because im no expert in all this!

 

[fragdrum]

Ill try posting a video this evening

 

[fragdrum]

Here is a video of what is happening...

https://www.youtube.com/watch?v=TXn1u0jKJqc

 

[RichB]

It looks like your tail servo direction needs to be reversed.

To check it, wiggle the tail with your hand. If the motor tilts into the wiggle, you have a problem. If the motor tilts away from the wiggle, you are good.

 

[fragdrum]

The servo is going the right direction. In the video, I am only giving throttle import and not touching yaw.

 

[BanditJacksRC]

its not about which way the servo is moving when you move the rud stick, but about which way the gyro is correcting any movment.

Althought I can't see the video from my office. so... maybe it is right!

edit: i also just noticed you said you didn't touch the sticks in the video

 

[BanditJacksRC]

just got it to work. yeah pick it up and wiggle it and see how the servo moves.. if it is moving with the movments, then go to your servo tab in cleanflight and reverse it (not in transmitter)

 

[fragdrum]

I never thought about that. Thanks for that suggestion!

 

[RichB]

The servo is going the right direction.

It might be responding in the correct direction to your stick inputs, but the flight controller is confused about which direction it should move the servo in order to stabilize yaw.

This is a configurable option for your flight controller, so go find it and reverse it.

Then, reverse the channel on your transmitter if needed