RotorPixel Gimbal Technical Discussion

[cavaleiro01]

I'm convinced DJI will launch their 3 axis gimbal for the P2V before Rotorpixel is able to do it...

 

[MikeySoft]

I'm wondering if the forward position of the camera on the gimbal affects the CG of the Photon requiring more power on the front props to keep it level? Looks like the gimbal control board is mounted in the back but I'm not sure it will help keep the CG near the center.

 

[Flighttime]

I'll be interested to see Rotorpixel's 3rd axis upgrade. I'm assuming it will use a different style of motor at the top to keep the height of the unit down, but looking at how the gimbal arm attaches to the mounting bracket it has potential to be a straightforward bolt on, plug in job...

Yes the mounting arm looks easy enough to stick a 3rd axis motor. Ive been looking at gimbal motors in the market and found that the optimum size and weight is still the same size as the ones used in the pitch and roll axis....unless of course, Rotopixel comes up with their own motor sizing for the third axis otherwise it'll be catch landings and takeoffs all the way.

As for the controller, its nice that RP has prepared a connection socket for the 3-axis expansion board (hence no soldering required) but that'll also mean theres going to be additional weight from the new controller expansion board, power cable, controller housing...etc. Basically it'll look and feel bulkier than the H3-3D or even the CNet P2V+ gimbal that been going around.

It won't matter so much though if you plan on moving it to a bigger frame multirotor.

 

[Flighttime]

This video may be useful for those struggling with shakiness and thumbscrew tightness:

http://vimeo.com/91132582

 

[gpauk]

Shame there's no image of his RP installation. You can't tell if he's installed the damper screws correctly or not (like the HPI guy vid had not done it correctly...)

 

[Xcopter]

Considering how low the RP 2-axis already is I would imagine that the skids would need to be upgraded to taller ones to accommodate the 3-axis upgrade. The P2V+ looks like it has taller skids as well.

 

[Pull_Up]

I'm hoping Rotorpixel will engineer a light removable/swivelling extender set so you can still use existing landing skids and therefore flight cases, etc.

 

[cavaleiro01]

I already ordered higher landing skids, just in case...

 

[gfredrone]

Does the RP gimbal work with v3.0?

If not will it be possible to trick the software into thinking the RP gimbal is a H3-2D and have the FPV roll mode available with the 7th channel active.

 

[cavaleiro01]

I went for these, instead: http://www.ebay.com/itm/121295635931?ss ... 1497.l2649

and these, also: http://www.ebay.com/itm/181289975412?ss ... 1497.l2649

Now I have more room to attach longer range antennae and boosters...

 

[mr_3_0_5]

I though you could use the regular landing skids

 

[cavaleiro01]

I though you could use the regular landing skids

mr_3_0_5, I'm still waiting for my rotorpixel gimbal and I already feel the need for taller landing skids, after adding the dji lens filter kit. When I set my camera to look down, it is already hitting the ground, so, imagine after I add the gimbal.

 

[Pull_Up]

I have the Rotorpixel and stock landing skids with lens filter kit. I take off from my case and hand catch. The lens kit does touch the flight case lid but Rotorpixel have confirmed that the bounce you get from the gimbal trying to level itself does not cause any harm to the gimbal. When a third axis kit is available then we will need extra height. However I'm hoping Rotorpixel comes up with a simple skid modification that can be easily removed or moved so that we can use our existing flight cases.

 

[FlyingFox]

Have any of you adjusted your gains, with the slight extra weight the gimble has, I was thinging the vertical may need to be increased to maintain a good hover with no loss of height ?
Or would all need to be increased to balance it ?
Or no need at all ?

 

[Pull_Up]

I haven't messed with gains yet, and for standard photographic flying I don't think you'll need to - the response is fine. I would like to do some excitements with gains to see if I can't lower the yaw correction response if the aircraft but not sure if that will work. One in my to do list for after my holiday.

 

[gfredrone]

I think mine is defective. It's making a loud buzzing noise at rest and is dropping on the pitch axis. I'll post a video in a few. All this time waiting and it's a no go.

 

[gpauk]

Check -- vis a vis Pull_up's videos -- that you have the damper screws correctly fitted. If not, you can get the pitch cable trapped between the PV body and the gimbal plate, and it will be unhappy. Also double check that the cam is not touching anything at all, and that the PV is level and stable when you power up and wait 5 secs. The gimbal imu calibrates then, and it needs to be clean. I have to put each leg on a small prop (like the dvd cases in one of Pull_ups vids) else the cam will rattle on the table and not calibrate correctly at power up.

 

[gfredrone]

Ok, fixed the dropping pitch axis by rebalancing the camera for the lens filter kit and lens filter. My new pitch balance setting is near the middle. I also had to move the roll balance over a tiny bit.

I think I'm still having some strange noises. It's a very loud buzzing/humming noise and vibrations coming from the gimbal motors. No wires are catching and damper screws are inserted correctly. Gimbal seems to be functioning properly.

 

[gfredrone]

Humming and buzzing noise coming from RP gimbal motors. The noise starts at about 26 seconds in the video and really gets going at 42 seconds. It also makes the noise at power up sometimes while just sitting there. Is this normal?

[youtube]http://www.youtube.com/watch?v=aZmQNT-hZ5Y[/youtube]

Update: I think I've narrowed it down to the pitch motor. I'm already in contact with Keri and he his diagnosing the video files on his end.

[youtube]http://www.youtube.com/watch?v=aFXSQhubIbM[/youtube]

Update: Whatever is causing the noise is getting worse. The pitch motor makes the buzzing and vibrates like a mad dildo all of the time now.

 

[gfredrone]

I found some software tuning instructions.

http://aerialpixels.com/support/alexmos ... ing-guide/

I wonder if this can be noise issue can be fixed in the GUI program.