DJI 450 Yaw "Recoil"

[Witterings]

Whenever I use right yaw and let go of the stick it jerks back to the left the second I let go so it's hard to fly straight and I'm constantly having to correct / overcompensate, anyone any idea what it may be??

I was going to try doing an IMU Calibration to see if it makes any difference, do I have to do that outside where it can pick up satellites or doesn't that make any difference and I can do it inside?

 

[Pfuschendennarr]

I don't know the solution except to guess that your center of gravity might be off.
I am having trouble with this on a a big quad using a reptile frame, if I yaw hard left to hard right the thing nearly drops itself.

Lower yaw gains will help, but of course you lose at turn speed.

 

[Witterings]

I'll double check CoG and see of that makes any difference, you can only change the yaw gain in basic though which will only affect how the quad responds /corrects to wind etc and not your stick unless I'm wrong ???

 

[Pfuschendennarr]

You could change your exponential values, I don't know why it turns though, i have the same problem. :| I'll letcha know if I find anything out.
But yeah for now to be safe, you can try keeping your gains super low (mines at 60 for a big quad) but even then, jamming hard left to right can cause it some issues. It doesnt crash itself like that though. Throttle + yaw works good.
Hope we figure it out the kicks soon.

 

[Benjamin Kenobi]

Whenever I use right yaw and let go of the stick it jerks back to the left the second I let go so it's hard to fly straight and I'm constantly having to correct / overcompensate, anyone any idea what it may be??

I was going to try doing an IMU Calibration to see if it makes any difference, do I have to do that outside where it can pick up satellites or doesn't that make any difference and I can do it inside?

Hey mate. That problem is in the manual. It's a gains thing. It says to increase the gains until it does what you've described, I think anyway. What gains have you got on YAW?

 

[Witterings]

What gains have you got on YAW?

I've tried the original default which I think believe was 100 and is the same as the suggested in the manual although the pitch and roll gains suggested in the manual are higher that the default, I did try increasing it to 140 which someone else had recommended and it was the same.

 

[TheUFGadget]

Hi there!

Get you a small bubble level and put it on the motor stem. I had this EXACT same problem with one of my craft and it turned out that a motor was angled ever so slightly. This can happen if the screws are not tightened the same amount, etc. Also use the level on your arms...If they have flexed due to a crash that will cause you some back yaw as well. Hope this helps!

 

[FixedWing172]

It's a DJI Naza thing. Believe me I've been there, first with my 450 and the same results with my 550. Ended up pushing my Yaw gain up to 200+ which helped. Because of the yaw oscillations I've invested in a 3rd axis for my gimbal. Now I'm battling jitter in the yaw which I will hopefully tame but it looks like post production stabilization may be necessary.
Here is a vid of my 550 before I bumped up the yaw gain http://youtu.be/YEdGE0T-zu4
Here's a vid of my 550 after I increased the yaw gain http://youtu.be/LzZzUw9xOXY

 

[Witterings]

Hi there!

Get you a small bubble level and put it on the motor stem. I had this EXACT same problem with one of my craft and it turned out that a motor was angled ever so slightly. This can happen if the screws are not tightened the same amount, etc. Also use the level on your arms...If they have flexed due to a crash that will cause you some back yaw as well. Hope this helps!

Totally get what you're saying, someone on another forum (I'm desperate to find a cure) suggested swapping the front 2 arms and test and then the rear to arms and test to see if switching either had the reverse effect, that would pretty much identify the same potential problems as you've suggested but just using a different method to diagnose them ????

It's a DJI Naza thing. Believe me I've been there, first with my 450 and the same results with my 550. Ended up pushing my Yaw gain up to 200+ which helped. Because of the yaw oscillations I've invested in a 3rd axis for my gimbal. Now I'm battling jitter in the yaw which I will hopefully tame but it looks like post production stabilization may be necessary.
Here is a vid of my 550 before I bumped up the yaw gain http://youtu.be/YEdGE0T-zu4
Here's a vid of my 550 after I increased the yaw gain http://youtu.be/LzZzUw9xOXY

Certainly the 1st video you show at 33/34 seconds and more noticeably at 50/51 seconds that's EXACTLY the same as I'm getting ......... mine may be a bit worse.
I've been going the wrong way with the yaw gain in that case, I thought it may have been because it was too much, I dropped it down to 80 today to see how it responded and was just the same.
Do you remember what you had it set at on the 450, is it the 200+ you refer to or is that the 550 ??????

Also just interested what gimbal (hardware) you're using on the 550 as that's the exact same set up I've been wondering how to achieve ..... 550 / Nex 5, the Alexmos you mention in the video, that's just the controller / software rather than the gimbal itself????

If that's you're place you're filming at, nice place as well

 

[FixedWing172]

Totally get what you're saying, someone on another forum (I'm desperate to find a cure) suggested swapping the front 2 arms and test and then the rear to arms and test to see if switching either had the reverse effect, that would pretty much identify the same potential problems as you've suggested but just using a different method to diagnose them ????



Certainly the 1st video you show at 33/34 seconds and more noticeably at 50/51 seconds that's EXACTLY the same as I'm getting ......... mine may be a bit worse.
I've been going the wrong way with the yaw gain in that case, I thought it may have been because it was too much, I dropped it down to 80 today to see how it responded and was just the same.
Do you remember what you had it set at on the 450, is it the 200+ you refer to or is that the 550 ??????

Also just interested what gimbal (hardware) you're using on the 550 as that's the exact same set up I've been wondering how to achieve ..... 550 / Nex 5, the Alexmos you mention in the video, that's just the controller / software rather than the gimbal itself????

If that's you're place you're filming at, nice place as well

Go at least 200 on the 450 yaw gain. The gimbal is a GotHeliRC two axis gimbal. I've upgraded it since these vids to the 3rd axis but it's far from perfect so far

 

[TheUFGadget]

Totally get what you're saying, someone on another forum (I'm desperate to find a cure) suggested swapping the front 2 arms and test and then the rear to arms and test to see if switching either had the reverse effect, that would pretty much identify the same potential problems as you've suggested but just using a different method to diagnose them ????

I beleive that it would be however I do not have enought knowledge to tell you if it SHOULD twitch the other way. I do know that was my issue and once I fixed it the quad was VERY locked in. I have NEVER used a yaw gain above 120 for my 450 when filming (I don't fly acro though).

 

[Witterings]

Go at least 200 on the 450 yaw gain. The gimbal is a GotHeliRC two axis gimbal. I've upgraded it since these vids to the 3rd axis but it's far from perfect so far

I haven't managed to try this yet simply because it's been raining since I saw the answer and back to work today but I was thinking about this and can't help but wonder if it's treating the symptom rather than the cause if that makes sense. I'm sure your gains aren't meant to be so high otherwise there would have been lots of people that instantly posted the same answer as they'd all have the same issue.
When you upgraded from the 450 to the 550 did you use the same parts or did you buy a whole new 550, I#m just wondering if you transferred the issue from one to the other ?? .................. Just a thought!

 

[Witterings]

It's a DJI Naza thing. Believe me I've been there, first with my 450 and the same results with my 550. Ended up pushing my Yaw gain up to 200+ which helped. Because of the yaw oscillations I've invested in a 3rd axis for my gimbal. Now I'm battling jitter in the yaw which I will hopefully tame but it looks like post production stabilization may be necessary.
Here is a vid of my 550 before I bumped up the yaw gain http://youtu.be/YEdGE0T-zu4
Here's a vid of my 550 after I increased the yaw gain http://youtu.be/LzZzUw9xOXY

I have now tried this and does has made a difference, I've only tried on 200 so far but will use that as a starting point and raise / lower from there to find the best level.
I still can't help but think there's an underlying problem though, someone suggested it may be that the ESC's aren't quite calibrated and one is responding slower / quicker that the other so again really would be interested if you transferred the parts from your 450 to the 550.

Also you mention yaw oscillation, is this made worse by raising the yaw gain ie will it just start to produce more jello ???

 

[FixedWing172]

I have now tried this and does has made a difference, I've only tried on 200 so far but will use that as a starting point and raise / lower from there to find the best level.
I still can't help but think there's an underlying problem though, someone suggested it may be that the ESC's aren't quite calibrated and one is responding slower / quicker that the other so again really would be interested if you transferred the parts from your 450 to the 550.

Also you mention yaw oscillation, is this made worse by raising the yaw gain ie will it just start to produce more jello ???

I didn't swap parts. I had two totally separate machines and experienced the same thing with both of them. I believe it's likely caused by the inexpensive DJI Motors and ESCs which is to be expected at the price point in which they are offered.

Raising gains will not cause jello. But then again there hasn't been any mention in this entire thread about jello. If you've got it that's a different issue all together.

 

[TheUFGadget]

I have now tried this and does has made a difference, I've only tried on 200 so far but will use that as a starting point and raise / lower from there to find the best level.
I still can't help but think there's an underlying problem though, someone suggested it may be that the ESC's aren't quite calibrated and one is responding slower / quicker that the other so again really would be interested if you transferred the parts from your 450 to the 550.

Also you mention yaw oscillation, is this made worse by raising the yaw gain ie will it just start to produce more jello ???

I doubt that is your issue. If you have to throw your gains that high I am going to guess you have an underlying issue. did you try the leveling idea?

 

[Witterings]

FixedWing,
Interesting hat you've had the same issue on 2 different quads that's for sure, I only mentioned jello in response to your comment on yaw oscillation and wondered if it may cause vibrations through the frame. You say raising the gains won't make any difference, someone suggested raising all the basic gains to 140 which I did, the video it produced was like a crack addict suffering serious withdrawal !!!!! and when I say bad I mean seriously bad footage!!!

UFGadget,
I've certainly had a thorough look over and had a spirit level on it, I can't seem to find anything that looks warped / out of line at all.

I actually bought the gain down to 150 yesterday and I wonder if that's just about enough, it's probably the most straight line / smoothest flight I've had since I bought the quad.
I also have 1 spare motor and 1 spare esc so I swapped them on the front right arm yesterday and no difference, I'm just going to go round the corners and change each one, wind the gain back and test it and just increase the gain if there's no change until I've done them all and see if any of them make a difference or not.