Hi guys, Duran here. We're going to be doing a precious gimbal video. We've had a couple of requests for a video just about the gimbal in terms of how to balance it, how to calibrate the gimbal, how to get it working optimally.
So first thing people need to realize is this is not a plug-and-play gimbal like the Zenmuse. We've made it for different cameras, the GoPro 3, the 3 Plus, different cases, even the older GoPro's.
So it's not a plug-and-play gimbal like the Zenmuse where you'll take one specific size camera and it just works. We obviously do set it up and balance it and calibrate it.
And we do test every gimbal before it leaves, but obviously depending on what camera and housing and FEV setup you're going to be using or want to be using, you may need to get into the gimbal software and just tweak things and fine tune a couple of things.
OK, so starting from the first part is balancing the gimbal. As with any precious gimbal, the most important thing is to make sure your gimbal is balanced. If it's quite far out of balance, it's not going to work properly.
That's when you'll start getting vibrations and funny movements and things.
So what's important is to balance both your roll axis. At the moment, ideally with a precious gimbal, if you move it, it's going to stay there.
At the moment, this one is a bit bottom heavy because it always comes back to level.
Keep in mind that ideally it's nice to have it perfectly balanced, but depending on how much power you're putting to the motors, it's not necessary to get that spot on.
I prefer personally mine with a little bit of a bottom heavy so it naturally weighs the camera down and it kind of helps the stability of the gimbal.
So in terms of left or right, this roll axis is pretty well balanced. It's not pulling to the one side or the other.
The next thing you want to obviously balance is your pitch. So if you move it, you don't necessarily want the camera dropping in any specific direction.
So you kind of want to make sure the camera is more or less balanced. So in terms of balancing it, you can use a little 1.5mm Allen key.
And to shift the roll, you'll see we have the four roll screws at the back. These you can simply loosen and you'll see the groove.
So you can shift the entire gimbal to the left or to the right. And the same with the pitch.
You can simply loosen the four little pitch screws and you can shift the entire gimbal forward or back.
And then also on the back gimbal parts, we have grooves in both ends so you can actually adjust the gimbal higher or lower.
So with a GoPro 3 Plus, the new case, it is lighter than the other one so you do need to adjust it slightly higher.
With the normal GoPro 3 case, it tends to work a bit more balanced.
So the first thing you want to do is make sure your gimbal is balanced as well as you can.
You also know the GoPro screw we have on the right hand side. We just find it works much better on this side in terms of balancing things up.
Another important tip that guys, you might not realize is you'll see we do have a black single sided foam on the back of the gimbal.
The GoPro must be pressed securely to that foam. If it's quite loose or not even touching, you are going to have vibration issues, especially if you're tilting down.
So that's a very important part of the gimbal.
So once you have your gimbal nicely set up, we can start tearing things up and getting settings by in tune.
One of the other things some people have mentioned is they find that the wires are getting caught quite a lot.
Personally, I haven't had that problem. Sometimes if you're pitched all the way down your roll or your pitch cable can get stuck to the GoPro nut if you're flying like that quite a lot.
If that happens, you can simply take a cable tie and cable tie your pitch motor to the arm of your roll arm.
Other than that, we have the IMU cable coming out the side and in all our flying and our testing, we haven't had it hook on anything.
Even if you pitch down, it doesn't hook and it's quite loose there so it doesn't create any issues.
So we're going to go ahead and switch the gimbal on. Our radio is obviously on.
Just another tip, you'll notice we've taken the props off. Whenever you're powering your drone and you're working on the bench and you're doing some testing, make sure you take the props off.
So this is safety precaution.
Okay, so we have the gimbal on and we have it working really nice. These are stock standard settings that I've loaded.
You'll see the cables that don't hook. If you have them in the right place, they're not a hooking and it performs really well.
So I think one of the main things guys have been asking is when they're tilting down, they have some vibration at about 40 or 45 degree.
I've obviously tried to replicate those problems. So let's just have a look at the main reasons for having vibration issues when tilting down.
Number one issue would be your GoPro is not pressing hot enough against the foam pad.
So it is quite, when it can be, if you have small hands, you might want to take a pies and just tighten this GoPro screw as much as you can and hold the gimbal by the aluminium part and press the GoPro against it just to make sure that it is indeed pressing really well against that back foam pad.
That's the number one cause that we've seen in our tests in terms of vibration, why guys are getting vibrations at about 40 or 45 degree angles.
The other reason would be settings. Obviously if your camera is not balanced, if it's quite front heavy or back heavy, top heavy or bottom heavy,
you are going to have, because at a specific angle, the weight is going to be off balance and the gimbal is going to struggle to keep the gimbal balanced.
That's why it'll kind of hook out of its position and then start oscillating. That's when the vibrations come in.
So those three things, make sure your GoPro is securely pressed against the foam pad, make sure your camera is balanced well and then we'll look at settings.
Settings are obviously the most important. We do run a AlexMoss gimbal controller.
So for those who have worked with AlexMoss gimbal controllers and brushes gimbals in the past, it is the best available in terms of brushes gimbals that you can use with a bunch of different gimbals.
But it can be pretty technical to get to know and get to set up, especially in the settings and the PIDs. So we'll just have a quick brief look at that.
So I have the gimbal on. We have the gimbal balanced.
And right now, I mean, we aren't getting any vibration issues, but I'll go through the settings and just change a couple of things and show you when we do start seeing vibration issues.
Also, just to keep in mind, when you have the quad on the table and you are doing setups, the drone is quite springy because of the cold fiber legs.
It can be quite jumpy or springy just in terms of the material.
So if you do have settings in your arm moving the table around, you might want to put the drone on a sponge pad or foam pad just to get the drone all four isolated from the table.
That might help. Keep in mind, we do want to have the settings ideal for when we're in the air, not when we're landed on a solid table.
So these fine vibrations do have an impact on the gimbal, as you can see.
Once you're in the air, that's what we're looking for.
So the gimbal is on. I'm going to plug in the USB. The software you can obviously download from our website. I have it open here.
So first thing you want to do, once you plug it in, it'll assign a COM port and you simply click your COM port and click connect.
So once you've done that, the gimbal will go connect.
So in the program, on the right hand side, you'll see the roll, the pitch indicators that show us what's actually happening with the gimbal.
So another issue some guys have had is when they're pitching down on your radio, so when you take the radio and you actually pitch the gimbal down, they say that they're getting in the roll, they're having a bit of a roll influence when pitching down.
This happens for a couple of reasons, but two reasons mainly is if your IMU, which is obviously on the back of your gimbal, if that's not squared up in terms of 90 degrees with your drone and you calibrate when that's moving down,
you're obviously moving the IMU down off axis. It's not 90 degrees square with the drone.
It's important to make sure that when you have the gimbal set up that everything is lined up and balanced and 90 degrees.
So if you're pitching down, the IMU is not doing that or that, it's actually perfectly on a 90 degree axis tilting and pitching.
That's the main reason. Another reason is just, again, settings if your calibration of the accelerometer and the gyros aren't done correctly.
So I'll quickly just show you how we prefer doing the calibrations is, okay, I'm connected to the software.
So all I'm going to do is on the software is disarm the motor so you'll see the gimbal has gone limp.
So what I'm going to do now is perfectly align the gimbal in terms of getting the IMU as vertical and horizontal as possible, not the camera, not the gimbal, the actual IMU sensor.
So I normally put my finger there and keep this horizontal with the airframe.
It's quite an easy way to see. You can see the top of the roll plate and then the obviously airframe.
It's easy to see that horizontal there in parallel.
And then obviously, as I said, you want to have the IMU as flat as possible, not the gimbal.
So that's more or less horizontal. And then in the software, you want to click calibrate accelerometer.
So now at this point, you want to keep it dead steady. You don't want to move it or have vibration.
Once it's done, the motors will click back on. So what you want to do then is click right.
After you've done that, you want to disable the motors again with the motors on or switch and then do the exact same thing and in the exact same position.
So you want to keep your roll 100% horizontal and then you'll pitch exactly the same.
And then click gyro and calibrate gyro. And again, keep it still as you can.
Once it's done that, the motors will come back on and you press right for the second time.
So that's how we do the calibration for both the accelerometer and the gyro.
It's important to do them at the same time.
And when you do go and change settings, you want to obviously redo the calibration after you've made those settings.
So now, again, we have really good stabilization, pitch and roll.
And if you're yawing, it's an easy way to tell if you're pitch, if you're going to pitch down and you get roll,
if you yaw, you should also have some roll influence, which you obviously don't want.
So now we don't have any real roll influence on yaw, so everything's looking good.
So just in terms of vibration at a 45 degree angle, two main reasons,
apart from the other reasons that I said if your gimbal is not balanced and your GoPro is not hard against the phone,
your motor or your settings can be, you know, if you've changed things or if you've messed with settings,
or if you've got a camera different to what we calibrated the gimbal, you might have some problems.
In the program, you'll see we have PID.
Now, PIDs can get very complicated in terms of what they stand for.
But basically, in layman's terms, your P is the amount of power that is applied to stabilize the gimbal.
Your I term is the speed at which that power or that stabilization is applied.
And then your D, your derivative or your dampening term basically just adds a dampener to those two values or terms.
So your roll in your pitch, you'll see we have default settings.
You can email us at support and John will be able to send you the settings that we use.
And you can simply load them and start from a benchmark.
The thing with Alex Moss is there aren't any, you know, standard PID terms because of the nature of the brushes, gimbals.
And they are so different.
So there's no, you know, set benchmark in terms of these are the settings to use.
And this is what they mean.
They very much just random parameters.
So it does take a bit of getting used to and fiddling with the parameters to get what you want.
But basically, on the roll, for example, right now, our P is 20, which gives us a nice solid and smooth stabilization.
The I term you'll see right now is zero comma zero one.
If I make that zero and I press right, that means the speed at which it's going to correct is now zero.
So if I move the gimbal, it's actually not going to come back because I've made that zero.
So the item, remember, is the speed at which we are coming back or stabilizing the gimbals.
If I make that back to zero comma zero one, you'll see there's a speed at which it comes back.
If I make that speed too high, let's make it one, for example, the speed is going to be, actually, sorry, it doesn't go to one.
Let's make it zero comma one.
And I write that, you'll see the speed at which the gimbal now comes back is a lot faster.
But now what that does is because it's that fast, it overshoots and it starts oscillating like this.
So there's a specific, you know, kind of key area where you want those settings.
So zero comma zero one, you know, does the job quite nicely.
Zero comma one up until maybe zero comma four works quite well.
You'll see once you start changing settings, your calibration and things start going out.
So remember to always do the calibration again after you've changed and mess with settings.
So now let's just tilt the gimbal down to about 45 or 40 degrees.
Right now we don't have any vibration, no matter what I try and do to the gimbal.
It's nice and smooth.
So if I take the D term on the roll and I make that 20, for example,
you'll immediately start seeing vibration.
So there's a very fine vibration happening there.
And that's simply because the D term is too high.
So if I take that down, the vibration disappears once again.
Also, if you make your power too high, let's make that maybe 150,
you immediately get vibration again.
So if you are seeing vibration in your gimbal,
first thing you want to do is just dial down your gains a little.
So that's back to 100 and smooth.
We don't have any problems with vibration.
Another tip, a lot of guys, when they're pitching the gimbal down
and start getting vibrations, they automatically think it's the pitch motor that has the problem.
And then they start messing with the pitch settings in the software
when it's actually not the pitch motor, it's the roll motor.
It's a bit deceiving because you're all pitching down and then you start having issues.
It's actually the roll motor because the IMU sensor is moving which changes these settings on the roll stability
and that's where you start getting the vibration.
So most of the time it's your roll settings you have to play with, not your pitch settings.
And a way to do this is you can actually, on the pitch power, stick that to zero and press right.
So now our pitch literally doesn't have any stabilization,
but if you manually move it down to 45 degrees,
you should be able to pick up that vibration in the roll
and then you can go ahead and either dial down your roll power
or your D term in your roll just make it slightly less until the vibration disappears.
And it's as simple as that.
And then you can simply put your power back on your pitch
and we have everything working again.
So those are kind of the main talking points that have been online and on Facebook and the emails to us.
Once you understand how these things work and how brushless gimbals work,
they do a really good job in terms of getting really smooth and stabilized footage.
So please just let us know if there's any other questions or any other requests for videos you guys would like to know.
And obviously just email us at support and John will do his best to get back to you.
And obviously the Facebook group is a good place to chat about things and just let us know.
So I hope that helps and again just be in touch and happy flying.
