Aircraft Type: Innov8tive designs 800mm hex Gimbal Type: Cinestar Radian Type ( 1, 2 , 3 axis): 2-axis Gimbal Power source: 6V from CC 10amp BEC, powered fro 3S750mah Gimbal Radio Type: Tilt control from Spektrum AR9010 Radian Communication Protocol (S.Bus, PPM, PWM, Spektrum): PWM Symptoms: 2-3min into flight the roll axis would dip to the right. Steps taken to resolve: To clear the drift i would have to land and power down the gimbal and then power it back up. Also I noticed if i would yaw clockwise it would clear the drift for about 30sec and then start to drift again. I noticed it a lot today with the shooting with my GoPro, don't have a bigger video camera yet, but i notice it when i shoot with my Canon Rebel XSi, just takes a bit longer for it to appear.
Paul please send over photos of how you have the Radians mounted and screen shots of the roll configuration setup.
Also, how are you powering the gimbal? Please be specific as in "battery type" -> BEC -> which ports on the Radian. Ive also had a random roll issue in the past due to what I believe was interference. Photos will help!
Thank you for the quick reply, ill get the photos and I for to you first thing in the morning. With another shoot next weekend for a local TV show I need to get this fixed quick.
Paul: Does this rapid roll to the right only happen in flight -- if you power up the gimbal but do not power up the motors, does it also happen? i'm heading down the same thought chain as Brad -- could there be interference from the motors that is somehow causing a problem? The next thing I'd try is swapping over the Roll and Tilt Radian sensors, but before you do that let's wait to see the Radians are mounted and the configuration as Gary suggests. Andy.
Gary - Here are the photos of how the gimbal is mounted and the radians. I have them mounted with the double side tape supplied with the radians. Brad - the power comes from a Thunder Power 3S730Mah 25C Pro Lite - Castle Creations 10AMP BEC (at 6V output) - into channel 2 on the Roll radian. I only need tilt control with this bird so there is no cable from my receiver into the roll radian for slew or mode select. Andy - Had it hooked up for 10min on my landing base and no drift. I then grabbed 2 arms and "flew" it around my room for another 5 min and no drift at all.
One issue could be the 6v going to the Radians. That voltage is passed through to the servos which are 5v. There has been discussion on the 6v disrupting or possibly killing servos. Your roll settings look normal to me. Is the power supply that you have running up next to the roll servo? I can't quite tell in the photo. That could also cause interference. Ill let the other guys comment as they may have better advice.
Ill try dropping the voltage down to 5V and see how it works. As for the power supply its sandwiched between the center plates of the bird and I run the wire through the vertical tube of the gimbal.
Paul you also don't have the mode set to control the radians. I don't Remeber the default but it mat be that without the mode being switched it may not be fully active. Also is the rx you have really a 1024 model?
I had enough wires running around and didn't need roll control so that's why I never ran one. If it could fix the problem ill run one and set it for just mode control and also drop the voltage to 5V an do some test flying. Also the spektrum 9010 has a resolution of 2048. So should I then uncheck that box, I though it auto recognized it and selected it for me. Just as another bit of information about the setup is its for a signal operator, so my receiver controlling the bird is the same I'm taping into a channel for gimbal control. Not sure if that makes a difference or not, just trying to give an much info as I can
I would rewire it so that the receiver is on the roll and then tilt is powered by roll. Also I would set it up for the mode switch that way you can eliminate something funky that may be going on there. I'm not aware of anyone running it like you have. The mode switch will also help you in that if it did happen again you wouldn't have to land to reset, just mode switch off then back on and continue. If the problem still persists this will at least get you through the shoot should it happen.
I though if running a regular receiver you had to run a separate wire for each radian? Do a new firmware allow to signal to be passed from the radians?
If you are using the Spektrum Satellite Rx, then that emits S.bus so you don't need separate wires to each Radian -- they talk S.bus amongst themselves. If you're using the Spektrum main receiver, then you will need separate wires as that emits PWM to each of the servo ports. You really do need to have Mode control on all of the Radian sensors or servos. There will be times when you really want to power down the entire gimbal mechanism. (Anyone else thinking, "oh gawd, Andy's landed it in a tree?" ) Andy.
SO i dropped the voltage to 5V, and now have a mode select for the roll axis. Ill do some flight testing tomorrow and let you guys know how it goes. Hopefully that fixed the problem.
Well that did it, not sure if putting a mode switch or dropping to 5V did it but now the roll holds true. Now and interesting issue has appeared. When I rotate the tilt will rock up and down. I'm guessing its just a gain issue but its still weird that now its showing up.
Hi Paul: Glad that you got it fixed. When you say "rock up and down" -- do you mean oscillating or just does it once? If it is oscillating, then yes, that is more than likely the gain settings for tilt. Andy
I guess you could say oscillating but only when i yaw the bird, once i stop yawing the tilt goes back to normal.
Oh. That's novel. (Sorry. British Understatement.) Could you connect up to each of the Radians in turn and take and post screen shots of the Diagnostic and Configuration windows please? I'd like to just provide a second pair of eyes to look over how you have it set up. Thanks Andy.
Thanks, Paul. The tilt gain might indeed be a little high (see this Google Doc spreadsheet that Gary has set up) https://docs.google.com/spreadsheet/ccc?key=0AvZl8S9wZihWdHBhV3F2ZXZLQm5zM2hfci1tN1pPdlE#gid=1 That said, I see some folks running at higher gains for the tilt. What puzzles me is why the interaction between the tilt and the roll. I notice that you have not Mode control, nor Slew control for the tilt. Are you running with both axes on "automatic?" Andy.