CANNOT get this brushless gimbal to work correctly.

[MKMaverick]

Let me first say that out of the box it WAS working pretty well....but I've since managed to mess it up completely and now cannot get it back.
It's a cheap brushless gimbal from HK, the Quanum mid-size if anyone wants to look it up....however it doesn't have the same controller pictured, or talked about in the discussions on the product page. It's a long skinny board that fits right down the back of the gimbal bracket, no real identifying marks.
I tried everything and couldn't get any version of simple BGC GUI to work (would just say "connecting to commxx" but never connect)...so after further investigation I came to the conclusion that it was likely a martinez controller (or at least a clone) due to the atmega328 and silabs chips. (yes, that's really all I went on) Well...that and the fact that I was able to update firmware using the instructions on the BruGi project page.

So I went ahead and updated firmware to the latest version and was able to connect to the BruGi GUI...and now the thing just flips out regardless of settings.

The camera is balanced in the mount, but no matter the combination of PWM, P, I, and/or D I dial in...it still just jumps around. I've tried different FW versions and have sat there playing with PID settings for hours....nothing.

So apart from completely regretting trying to tune it perfectly...I would like to at least get it back to where it was. Anyone have any ideas? or maybe have one of these with the new controller and managed to update/tune it?

 

[Motopreserve]

Have you contacted HK to see if they can point you in the right direction for the type of co roller it is? Also, they may be able to tell you the firmware that is flashed at the factory.

I know hey are notorious for bad CS, but it's worth a shot?

Before you messed with the PIDs, did you adjust the motor gains? The motors could possibly need to be polarity reversed. This makes gimbals act crazy like you describe.

 

[MKMaverick]

I don't think I did...this is my first brushless and my first attempt at tuning so I'll admit I haven't done a whole lot of research into the settings at this point. All I changed were the PWM, P, I and D settings. I did try changing settings with the "reverse" box both checked and unchecked for each motor (pitch and roll axis) and there was a definite attitude change. It was pretty clear that the roll motor needed the reverse box checked, and the pitch did not.
In the tuning instructions it says to zero out all those parameters, then set P, I and D to 5....then start increasing PWM until the motor starts to vibrate....but mine doesn't ever vibrate, it just starts to gently "rock" back and forth at about 2% PWM and then slowly increases the rocking motion as I increase PWM, but even at 100% it doesn't vibrate, just keeps rocking back and forth.
Then it says to increase P until motor vibrates....but With PWM anywhere above 10%, as soon as I start to increase the P value it just spazzes out for lack of a better description, and gets worse as I increase P....again, it never "vibrates".
Upping the D value doesn't seem to have any effect, regardless of the P value
I'll try sending a note through the Quanum site and to HK, but I'm not expecting much in the way of help...I'm assuming if there was documentation it would have been included with the product.

 

[Motopreserve]

I think the best thing to do at this point is to strip it back and proceed as simple as possible.

First, make sure you have the most recent firmware version.

Second, remove all motor connections except the Pitch motor. Power up the gimbal with the battery, and then connect to the computer.

I would start with the PIDs set a little higher to see if we can get them to act "normal." Set PID for pitch to P=10, I=.1 and D=5. Raise the power of the pitch motor slowly and see if you get it to shake. If you do not get shaking, try lowering the power back down, raising the P up to something like 30, and then slowly raise the power again. See if you can get it to shake at high frequency (less rocking and more shaking). Try this with both normal and reverse motor box checked.

Less us know if you can get this to happen.

 

[MKMaverick]

The problem there is that the motors are hard wired to the board...I could probably do small bullet connectors to avoid desoldering/soldering to the board multiple times...but before I do that, would just zeroing out the roll motor settings (power and PID) be adequate? With no signal to the motor I don't see how it would be any different than disconnecting it completely. I'll try that first anyway and see if I can get it to work.
thanks for the tips.

 

[Motopreserve]

Definitely try that first. Should act the same (or close enough).

And you can do that same procedure for all the motors - just mark your settings for each motor before putting them to zero.

Let us know how you make out.

 

[MKMaverick]

ugh...so I figured out my problem...and it's actually quite embarrassing.
I followed your procedure, and I was able to get it vibrating...and then it seemed like I was getting somewhere with tuning, upping P until vibrates, then upping D until it settles, but as soon as I moved the mount, or made too much of a change it would go crazy again!

Turns out when I moved the IMU I mounted it under the camera tray sideways...

 

[Motopreserve]

Ah. Always a sure path to frustration! . Don't sweat it - happens to everyone at some point.

Just glad you're on the right track now. Tuning these things to be "perfect" can be tough, but it definitely helps to have the IMU working correctly!