32bit + red scarlet yaw problem
  • Hi all.
    Im pretty new to the gimbals and just bought one with ipower 8017 and im trying to make it work. Two axis works pretty well but the yaw have some problems. Actually it works but the motors are dropping down the gimbal at some point. So vertically twisting is 100% good so the the upper handle can be twisted around with any speed and its cool but when i turn the gimbal into the vertical side (roll side) it keeps stable for a few degrees, around 35 degrees each side then the gimbal loosing its yaw position and turns to the side. I want to fix that problem and dont know where is the problem. Is the yaw motor Ipower 8017 not strong enough or is there something wrong with the tunning? Im using a 4S 14.8V 4000mAh battery.
    Many thanks,
  • "into the vertical side (roll side) it keeps stable for a few degrees, around 35 degrees each side then the gimbal loosing its yaw position and turns to the side."

    Do you mean position like on this video 0:30 - 0:38?

    Not holding like this could be many things.

    1. gyro calibration or installation is not good enough, did you perform 6 point calibration

    2. offset calibration is not good enough (but should not affect basic mode, except maybe if 'Estimate angles from motors' is used)

    (On what mode do you have this problem? I am assuming on basic mode. )

    3. Yaw axle is not well enough balanced

    4. The gimbal is not solid enough, making the gimbal as compact as possible helps (short tubes). Tilting the handle 90 degrees up causes huge momentum to the Yaw motor axle, especially if the camera is far away from it. This momentum can cause friction on bearings etc.

    5. And it could be combination of all the above mentioned and/or PID /Power tuning.

    More information would be needed, video would help.

    Are you using one or two IMUs? Using second IMU could help, though the best solution IMO would be making it work first with one IMU and then adding second. (Second IMU would provide additional security for the operation of the gimbal)

    Ps. 4S 14.8V 4000mAh is big and heavy. where have you placed it? If above Roll motor at Yaw axis, this could be at least partially causing the problem.
  • Hi. I will make a video and place it. On linked video its the 0,24-0,28. Battery is placed above yaw, next to the handle. I tried to make ad compact as possible but need to leave some place for the red cables. Today evening i will be able to make some video. I calibrated 6 points and using only one imu yet. I have a 2. Not connected yet. Gimbal is on basic. No follow mode yet. Many thanks, Anton
  • What do you have as RC Angle min and max. They could be limiting the travel. I am not sure if they limit in Basic mode, but on Follow and RC mode they do.
  • Angles were set by default: -45 and 45 to each. Tried to change but no effect. Here is the video! Many thanks for the help Garug!
  • At 0:06 why is the Yaw movement causing that kind of noise, it is really weird as is how it looses control.

    at 0:19 and 0:30, what is actually causing the movement, is it the motor? or is it doing similar movement if doing the same without power on?, i.e. is the yaw really balanced. I am asking, because it looks the motor is really giving up, so there should be some force causing that.

    So if you tilt the handle 90 degrees up, power off, can you but the yaw axis to any position so that it remains on that position? It is difficult to see on the video, but for me it looks like the Yaw motor is almost on top of the camera. It should be further back to balance the roll motor and its assembly weight.

    What kind PID and Power values do you have on Yaw? Is this with one IMU?

    You could try to tune it like this http://www.rcgroups.com/forums/showpost.php?p=28045237&postcount=9447 this is working well with my gimbal. How does the realtime display look with your current settings?

    This could be a broken motor, I had one that had one phase missing, it was still working, but not holding well. Can you measure the resistance of each 3 phase of the Yaw motor. it should be about the same.

    Also make sure that the motor inverted status is ok. It should be based on the video. However I ones accidentally connected the motor inverted and the gimbal was still working somehow, clearly not well, but I was surprised that it worked at all.
  • I was looking the video again this morning. To me it looks that also Roll and Pitch are not in balance, as it looks like the optical axis is on Roll and Pitch axis, if this is the case it can not be in balance as RED is bottom heavy and there is the weight of installation too.

    On well balanced gimbal, the camera should NOT return to level position after disturbed power off, but it should stay in what ever positions what ever gimbal part is but in to. Including rotating the handle upside down etc.

    It is difficult to see from the video if this is the case, but I would suggest to check the balance of all axis first.
  • The strange noise is the crappy grip of the handles. Actually i dont really know how to balance the yaw. I made it that way that if i turn it to the right (switched of gimbal) it stays there, if i turn it to the left it stays there aswell. With roll and pitch the same. Any direction i turn the roll, yaw and pitch it will stay there. At 0.19 and 30 i help with balancing. I feel the motors giving up. Its with one IMU yet. I tried many ways but the max power on motor gives the best result. Less power causes yaw giving up earlier. Im setting a very slow speed: 0,01 to all. Roll: P:8 I:0,01 D:20. Pitch: Roll: 10 I:0,03 D: 15. Yaw: P:7 I:0,01 D:12. I tried to paly arround with the setting but always the same result on yaw.
  • Tested few times again. Tried to balance it. It looks it balanced pretty well. Any direction i turn the gimbal it stays there. I also checked now whats happening after the gimbal makes this mistake what we are talking about. Right after the motors giving up it tries to get back to its position but not enough torque or power or something so i need to turn it back to origin position and than it turns back.
  • Now i placed a 5d mark ii on it which is 5 times lighter than the red and gives absolutely the same result.
  • If you turn the hole gimbal upside down (Power off) does everything stay in any position camera upside down etc. If you but the gimbal/handle sideways does Yaw stay in any position.

    Based on the video it looks you need to move the Yaw motor about 3" back at least. with 5D it should be in different place again.

    It is no use to try to find good PID values if the gimbal is not well balanced first.

    Your PID values are really low, especially you should get 'I' to much higher and I think P too unless you have selected gyro high sensitivity.

    These are good Gimbal/PID tuning instructions to follow http://www.basecamelectronics.com/company/blog/show/?newsid=69

  • If you can not move the Yaw motor backwards, try moving the camera forward. also it seems that the support under the Yaw motor (the semicircle) is missing supporting bearings at bottom?
  • Thanks for the help!:) finnally understood whats wrong. I thought the yaw was well balanced but it was not! I just sow few vids how is the balanced yaw looks like and when they turn the right or left it still holding its position and mine is loosing. As i understood i need to bring the vertical tube closer to the yaw motor which will be hard becouse there is a battery holder. Tomorrow will try to figure it out.
  • I removed the bearings untill the gimbal is not working 100%.
  • The user manuals really should better define what balanced means (before any gimbal tuning starts), with examples and pictures, it seems to be very common that this term is wrongly understood on gimbals, causing many problems.

    The circular front support is probably important part of the design of that gimbal, and it might be that it will not work well without it. Without it there is a high load to Roll motor/shaft and the gimbal is likely less solid without it. You probably get higher P and 'I' when it is installed (also on other axis than Roll) and better working gimbal.

    I do not know how significant the different is on that gimbal (I have never seen it), but I used a bit similar support on the first version of LeViteZer Gimbal, and that version really functioned better with the front support than without it. On later versions I decided to remove the front support, but needed to strengthen the gimbal, especially Roll axis support other ways.
  • Aggree. Many thanks for the help. Without you i would still playing arround with pid. Tried alot of things. Hogh i, hogh p,.. Should say hundreds of combinations. Finnaly know whats wrong.
  • I am glad I could help, let us know how you get the gimbal working.
  • Ok. Finnaly i balanced it and its working!! I had to skip the semicircle support ring becouse i didnt find the way to attach it and balance the yaw at a time but it works good now on basic mode. I could set the yaw follow mode and its working as well. Only thing is not working yet is the pitch follow. Gimbal goes crazy when im turning it on. Will try to figure out how to set it. Again thanks for the help.
  • Maybe at this point obvious, but I am still making sure: On the Video it looks that the camera is installed too low to be in balance (Pitch and Roll), is it now well balanced, i.e. the camera should stay in any Roll/Pitch position where you set it power off, it should not return to level.

    How solid is the frame without the semicircle support? If you move the gimbal fast up and down when operating, is the camera following solidly the gimbal or are the roll axis tubes flexing up and down. (the tubes are probably not flexing, but the roll motor axis/installation probably is)

    I guess a bit the later, because the designer of the frame has felt there is need for the semicircle support. Flex in here will affect Pitch performance. It would be good if you find a way to attach the semicircle support (can you move the lower installation points, was there a user manual for the gimbal?)

    Note: installing the semicircle will affect the Yaw balance, unless it is directly under the Yaw motor. It does not need to be under the Yaw motor, but if it is not, the Yaw needs to be rebalanced.

    If everything above is good enough then it could be:

    1. too high follow speed, set it to 3 on all axis to start with, you can raise it later on if needed.

    2. Perform IMU ACC calibration, if you did not do so already. You could start with one point calibration, but note that the camera/IMU is well levelled and stationary when performing it.

    3. Perform follow offset auto calibration, if you did not do so already.

    4. set the mouse over Follow PITCH,ROLL selection and follow the instructions to set the values.

    5. Set in RC control Min and Max angles to +/- 180, change later on if you like to limit the travel.

    6. What PID values do you now have for Pitch? They will affect also the Follow performance.
  • here is a video of almost perfectly balanced gimbal. I think the gimbal is solid enough without the semicircle thing. And i also think its kinda impossible now to put it up and keep in balance as long as the battery holder does not let to bring the vertical tube closer so the only way to keep the balance is to push the camera forward and there is a few centimeters then between the bearings and the semicircle. Now the red is without handle and its about 2-2,2 kg. maybe increasing the weight of the uploaded camera will let to pull it back a little bit right under the yaw so i will be able to connect the semicircle. I use the same PID as i did before. P10, I0,03, D: 15. But surprisingly the low PID values are working good. Im sure it can be better so i will play around with PID. And here is the video:
  • Looks much better now, but the handgrips keep terrible sound still ;-)

    What kind of deviation angles you get if you look the GUI when moving the gimbal?

    +- 2 degrees is ok, but I think it should be possible to get that gimbal below +- 1 degree.

    Your P and especially 'I' look still low. but you start seeing how this affect when you start shooting. If low values work, that is ok.
  • Oooook. Follow mode workin as well:) many many thanks for the help again! I have more than 2 degrees but will play around with settings later. Im allready pretty happy with thos results. Tomorrow will make some very first test shoot.