KK2,1/Tricopter/PID Tuning - Advice Needed

[BankNYank!]

Hello Everyone,

I'm having a bit of trouble tuning my first tricopter with a KK2.1 FC with stock firmware. I have built and flown multiple aircraft with my most recent being an H-Quad and a 450 size Hex; both of which were scratch builds. I had no issues getting them sorted and flying but I just can't seem to get this tricopter to act right.

I did go through and completely setup the new kk2.1 board before trying to fly and then followed Davids setup video step by step. Well with every step that applied since he was tuning a KK2.1 with Stevies firmware and I am running stock.

***Specs and Settings at bottom of post***

I tried using some of David's (RCExplorer) settings as a base but the thing was really wobbly (low oscillations I think) in self level and sluggish with self level off.

I tried raising P and I gains and limits in various configurations but never could get it locked in. I was able to get close with P set at about 150 and P limit at 100 and I at zero but as soon as I started adding I gain it would start wobbling again. I tried lowering the P setting and limit all the way down to 15 and things just kept getting worse.

I would adjust P and I settings first then go back and try adjusting the limits.

I understand that the P and I settings basically adjust sensitivity with P producing high oscillations and I producing low oscillations when too high and the Limits adjust how much input is given but I still can't seem to get this thing to act right.

Below is Davids recommended settings but everything is really sluggish and self level wobbles with these settings.

Roll and Pitch gains:
P Gain: 20
P Limit: 100
I Gain: 11
I Limit: 20
Rudder gains:
P Gain: 80
P Limit: 20
I Gain: 80
I Limit: 10


I am running The Flite Test Power Pack D and I also auto tuned the ESC's using the KK2.1 Throttle-Up-Press-Buttons-1-and-4-While Powering-On method. Everything is mounted on the ElectroHub with ten inch booms.

Any help would be greatly appreciated!

Thanks!

 

[razor02097]

The self level function requires tuning apart from the normal P and I settings. The recommended settings in David's video are a good starting point for the regular P and I settings but keep in mind that your tricopter is very different from the RCexplorer kit in the video. Depending on the battery, motors, props, and weight the P and I will need to be adjusted.

IMO ditch the stock firmware on the KK2 board. While it will fly a multirotor, it doesn't do well. It seemed like no matter what settings I tried there would be a scenario that the board would seem to freak out and oscillate like crazy. I never had any luck with the stock firmware so I broke down and bought the programmer card from hobbyking. I am running V1.6 aiO by kapteinkuk on my 250 quad and 1.9S1 by Stevies on my tricopter. I'm not saying this is the problem you are having but could potentially be a contributing factor.

If you increase the P gain a lot you should also bump up the I gain. If the P gain is really high and the I gain is still low the multi-rotor will wobble like crazy. A small multi like my 250 actually wobbled back and forth uncontrollably until it flipped over!


I'm sure you know the following but I want to add it anyway... Make sure your props are balanced and track well (aren't wobbling). Make sure the KK2 board is mounted at the center of gravity and mounted firm enough that it won't start to oscillate. Make sure to calibrate the gyro and accelerometer on a completely level surface. Lastly make sure your CG is where all 3 booms meet. Only then will you be ready to tune.

 

[BankNYank!]

The self level function requires tuning apart from the normal P and I settings. The recommended settings in David's video are a good starting point for the regular P and I settings but keep in mind that your tricopter is very different from the RCexplorer kit in the video. Depending on the battery, motors, props, and weight the P and I will need to be adjusted.

I totally get what your saying. I just wanted something to use as a starting place in my tuning.

IMO ditch the stock firmware on the KK2 board. While it will fly a multirotor, it doesn't do well. It seemed like no matter what settings I tried there would be a scenario that the board would seem to freak out and oscillate like crazy. I never had any luck with the stock firmware so I broke down and bought the programmer card from hobbyking. I am running V1.6 aiO by kapteinkuk on my 250 quad and 1.9S1 by Stevies on my tricopter. I'm not saying this is the problem you are having but could potentially be a contributing factor.

I don't have the programming cable but I can order one. Come to think of it I actually have a KK2.1 some where with a version of Stevies on it. I've read where a lot of people (even David) prefer Stevies on tricopters. I think I'll dig it out and give it a try.

I'm sure you know the following but I want to add it anyway... Make sure your props are balanced and track well (aren't wobbling). Make sure the KK2 board is mounted at the center of gravity and mounted firm enough that it won't start to oscillate. Make sure to calibrate the gyro and accelerometer on a completely level surface. Lastly make sure your CG is where all 3 booms meet. Only then will you be ready to tune.

I did all of this except balance the props.

On your advice I think I'll order a programming cable. In the mean time I'll try that other KK board I have with Stevies and see how it goes.

Than\ks for your recommendations and advice!

 

[BankNYank!]

I'm about a week late but just to wrap up this post I wanted to say that I flashed the kk2.1 with steveis firmware and all is once again right with the world.

Big difference and I highly recommend his firmware to anyone using a kk2 board on a tricopter!