CineStar 360 vibration issues

[bfrogner]

Having some 'hard-to-get-rid-off' issues relating to shake/vibrations on my CS 360 gimbal, here's a bit of background:

I have both a 2-axis and a 3-axis CS8 (btw, love both of them), but I have run into a vibration issue on the 360, I use exactly the same set up in MK config on both platforms, exactly the same set up on vibration dampers etc. There are only 2 major differences, the 3-axis gimbal and that I use a PicLoc on the 3-axis. Now, testing with both light and heavy payloads (NEX-5 and D800) I get basically the same result, vibrations on the 3-axis, none (well almost) on the 2-axis, although more accentuated on heavy payload which in a way makes sense.

I have not had a chance to compare with another CS 360 but it feels very 'sloppy' when you lift it up and shake it around a bit, and my guess is that this is where the shake/vibration originates, allthough I also have concerns that the PicLoc may introduce/accentuate vibrations as well (next trial will be to bypass PicLoc). I have tested with 'stiffening' the dampers by sliding in styrofoam? rods in between the damper rings and also using vibration gel pads between the dampers and the gimbal fixation plate, helps a bit but far from ok.

Any thoughts, suggestions, advise are more than welcome.

-Berndt

 

[osiris]

I was going to start similar thread just now. I had vibrations as well but have removed 2 rubber bands from anti vibration plates so now I have 4 on each. That got rid of vibrations. However I am still having quite an issue with shakiness. Here is the video I shot yesterday in the park. Now I just need to know from you guys if this can be improved somehow by playing with just the MK Camera settings or is it now purely down to my dodgy piloting skills. I only used 2D gimball so far connected directly to the MK flight controller.

http://www.youtube.com/watch?v=DGhmY_nGj1E

Cinestar 8 frame,
cinestar 2D gimbal,
MK stack with latest software,
MK fligt controller is controlling the gimbal,
ZIPPY 8000mAh,
APC 14x4,7 props,
shot with panasonic DMC-TZ5,
no post stabilisation.​

 

[Bartman]

If you'd like to try an experiment, wrap a couple of zip ties tightly around each vibration isolator and see what kind of video footage you get. Also, balance your prop blades and hubs as if your life depends on it..,...i think you'll be surprised by the results.
bart

 

[bfrogner]

@Bart: I did try the zip tie already, very unscientific field test but didn't get the result I hoped for, maybe I tightened them too much but somehow the whole point with isolators would'nt it be to absorb the potential vibrations from the rig and by locking them together you take away the functionality ? Will absolutely go down the prop balancing excerise, but the frustrating thing is that I get so very different results from my 2-axis vs my 3-axis rig, and the 2-axis has many more hours on the props and they've never been balanced.

Anyone know if there are different flex options available for the 'rings' (my theory is that even if I have all 4 in place they are too soft) ?

Thx for the feedback. //Berndt

 

[RTRyder]

I was going to start similar thread just now. I had vibrations as well but have removed 2 rubber bands from anti vibration plates so now I have 4 on each. That got rid of vibrations. However I am still having quite an issue with shakiness. Here is the video I shot yesterday in the park. Now I just need to know from you guys if this can be improved somehow by playing with just the MK Camera settings or is it now purely down to my dodgy piloting skills. I only used 2D gimball so far connected directly to the MK flight controller.

http://www.youtube.com/watch?v=DGhmY_nGj1E

Cinestar 8 frame,
cinestar 2D gimbal,
MK stack with latest software,
MK fligt controller is controlling the gimbal,
ZIPPY 8000mAh,
APC 14x4,7 props,
shot with panasonic DMC-TZ5,
no post stabilisation.​

A couple things to do, try increasing the P and I settings in the gyro tab and setup different flight modes in your TX with varying degrees of expo. I use three flight modes that vary from 40% down to 10% expo and no more than 75 to 80% travel with the highest expo setting with 100% travel ay 10% expo, makes the video a lot smoother. When I use MK electronics on my Cinestar 6 I usually have the P set to 140 to 160 and the I set about 20 point higher than what the P is set to, makes it much steadier overall.


With the gimbal servos controlled by the MK flight controller you need to have a only the signal wire connected and the servo power provided by a separate BEC, the MK does not have enough current capability to supply two servos with all the power they need especially if you have a heavy camera on the gimbal.

Ken

 

[osiris]

A couple things to do, try increasing the P and I settings in the gyro tab and setup different flight modes in your TX with varying degrees of expo. I use three flight modes that vary from 40% down to 10% expo and no more than 75 to 80% travel with the highest expo setting with 100% travel ay 10% expo, makes the video a lot smoother. When I use MK electronics on my Cinestar 6 I usually have the P set to 140 to 160 and the I set about 20 point higher than what the P is set to, makes it much steadier overall.

I have filmed these with the travel at 60% and EXPO on 50% on both Aileron and Elevation channels (on Graupner MX-20). Would you mind sharing also the Camera compensation values for Nick and Roll?

With the gimbal servos controlled by the MK flight controller you need to have a only the signal wire connected and the servo power provided by a separate BEC, the MK does not have enough current capability to supply two servos with all the power they need especially if you have a heavy camera on the gimbal.

I am only using a lightweight camera so far, however I will try that. I was not aware of this at all!

 

[Kari]

I also had some issues with CS vibration isolations. In my case silicone O-rings were too soft and they bend too much and couldn't keep the weight up. Result was that one or two corners of the camera mount plate were "hard mounted" to frame when O-rings bended through their slots. I replaced soft original silicone rings with a slightly harder rubber rings and so far at least it stays up in it's place better. Too soft isolation seems to be sensitive for jitters too.

 

[Tabb Firchau]

Berndt,

Can you do a flight with picloc turned off and report back? The 360 gimbal with the payloads you describe should be OK with the stock O-rings. I am still flying the same O-rings with a red Epic and they are working well. I have a hunch that the picloc is introducing vibration into the image. I have seen a similar thing in the past with stabilization systems when the gain is tuned a bit too high. Best way to rule that out is do a quick flight with camera gimbal completely powered off.

Let me know what you find,

Best

Tabb

 

[bfrogner]

@Kari - sounds very similar to my issue although I have not been able to confirm that the O-rings 'bottoms out', btw is this on a 3-axis gimbal and out of curiosity are your harder O-rings 'stock' or did you make them yourself ?

@Tabb - thx for reaching out, I will for sure try with gimbal powered off and report back, I am not confident that the Picloc is not involved, for sure I have noticed vibrations when gain and acceleration is set too high, current settings for roll and nick gain is in the 400s, minimal acceleration to the point where it's not fast enough. The reason I haven't tried it already is that I have been leaning more towards a mechanical shaking behavior rather than servo introduced vibrations, but I will do a field test, then we know.

Thx //Berndt

 

[siim227]

I was going to start similar thread just now. I had vibrations as well but have removed 2 rubber bands from anti vibration plates so now I have 4 on each. That got rid of vibrations. However I am still having quite an issue with shakiness ...

And i have similar problem to. Props. (and hubs) are correctly balanced. With turned off servos, the vibration will remain. The only one I have not tried yet, is to fix the camera rigidly to the frame and watch then ..

Best!
Siim

 

[Bartman]

@Bart: I did try the zip tie already, very unscientific field test but didn't get the result I hoped for, maybe I tightened them too much but somehow the whole point with isolators would'nt it be to absorb the potential vibrations from the rig and by locking them together you take away the functionality ? Will absolutely go down the prop balancing excerise, but the frustrating thing is that I get so very different results from my 2-axis vs my 3-axis rig, and the 2-axis has many more hours on the props and they've never been balanced.

Anyone know if there are different flex options available for the 'rings' (my theory is that even if I have all 4 in place they are too soft) ?

Thx for the feedback. //Berndt

ok. chasing down these problems is made easier sometimes by isolating each component to see if problems stop or get worse or stay the same. like Tabb said to turn the PIcloc off it's all part of isolating the problem.

 

[Kari]

@Kari - sounds very similar to my issue although I have not been able to confirm that the O-rings 'bottoms out', btw is this on a 3-axis gimbal and out of curiosity are your harder O-rings 'stock' or did you make them yourself ?

@Tabb - thx for reaching out, I will for sure try with gimbal powered off and report back, I am not confident that the Picloc is not involved, for sure I have noticed vibrations when gain and acceleration is set too high, current settings for roll and nick gain is in the 400s, minimal acceleration to the point where it's not fast enough. The reason I haven't tried it already is that I have been leaning more towards a mechanical shaking behavior rather than servo introduced vibrations, but I will do a field test, then we know.

Thx //Berndt

I bought exact same size but harder O-rings from local company which is specialist to all kind of sealing, rubber and silicone parts. But, i just heard from Tabb my plates holding O-rings might be from batch where slots were cutted slightly too big and letting O-rings to slip through. So i prefer to use original O-rings if that's the problem. Thanks Tabb for great support and listening users and solving problems here.

Kari

 

[bfrogner]

Feedback after a quick field trial today, did 2 flights, one with picloc enabled doing all stab, one with picloc (and complete gimbal) powered off. Indeed there is a difference, the way I have my picloc set up it causes vibrations during certain flight modes, not necessarily only when you stress it. The way I set gain on the picloc was by increasing gain until a servo started to oscillate and then pull back a bit, I'm going to do a bit more playing around with the settings since it feels like I have settings to aggressive, although too low gain and acceleration settings on picloc gets you into other issues around stabilization behavior, need to find the right compromise.

@Tabb - thx for eliminating the O-rings as the root cause, although I can see the value of having a couple of flex options for the O-rings, maybe something to consider for the future.

//Berndt

 

[JohnGore]

Feedback after a quick field trial today, did 2 flights, one with picloc enabled doing all stab, one with picloc (and complete gimbal) powered off. Indeed there is a difference, the way I have my picloc set up it causes vibrations during certain flight modes, not necessarily only when you stress it. The way I set gain on the picloc was by increasing gain until a servo started to oscillate and then pull back a bit, I'm going to do a bit more playing around with the settings since it feels like I have settings to aggressive, although too low gain and acceleration settings on picloc gets you into other issues around stabilization behavior, need to find the right compromise.

@Tabb - thx for eliminating the O-rings as the root cause, although I can see the value of having a couple of flex options for the O-rings, maybe something to consider for the future.

//Berndt

Have you managed to solve this issue yet? Pls keep us updated.

I am planning on buying a CineStar 2D to mount on my MK Octa XL, and if I have similar issues it would be nice to know where to start looking to solve it.