A little write up on my blog:
I have just taken receipt of a Fat Shark Attitude V2 kit from Unmannedtech. A review of the kit shall follow in a post later on, but in this I wanted to say about mounting the camera.
One issue I found when recording video on my quad is the problem of pitch movement, when the quad tilts forward or backward when moving. When flying from the ground or not recording footage this isn’t an issue. However if you are in forward motion, with the camera attached directly, you tend to see the ground. The reverse is true going backward, you see the sky. I wanted to prevent this motion for my FPV camera, making it face forward no matter the motion of the craft. Fortunately I had a servo laying around from an old, defunct, project. This combined with the APM’s built it servo stability control gave me a reasonably simple solution. I say reasonably as I still had to attach the camera too it.
I looked about for some ideas on a mounting techniques use for other stabilisation systems. Most offer pan/tilt or roll/tilt (some all 3). All I needed was the tilt portion of any system. My first idea was to mount the servo to the frame and then the camera to the servo’s armature. This ended up with a large, wide and tall system not that suitable for the space available on my quads frame. A quick image search showed a number of system that have the set-up swapped. The armature is attach to the quad and the servo moves. This led to my current design.
Once the tilt was sorted I moved on to the next issue with CMOS based cameras (jello). This is where you end up with the image ‘wobbling’ due to high frequency noise from the motors, props etc. To help resolve that problem I used the 4 vibration grommets that I brought from HobbyKing and never used. To be honest I am not happy with them, they are a little soft making the assembly wobble, but it seems to work for now.
Attaching the servo to its horn, I set the central position to point the camera down slightly, this is so I don’t have too much sky in frame, but enough to give me an idea of roll. Overall I am happy with the result. Video is smooth enough to fly with, given the 5 minutes I fly in the gusty winds we were in! The servo is way more powerful than I needed, this also makes it a little slow to move, but seemed to cope okay. I may end up switching to a smaller, lighter and faster servo if performance is an issue.
YouMagine link to design files