Tuesday, 21 May 2013

Stabilising camera mount design.

After my rather disappointing results trying to get aerial footage from my kite I've designed a mount for the camera. I know I could have Googled a design but for me half the fun is in the design and prototype stages of the project.

I decided against gyroscopic stabilisation, the cost of the three powered precision gyroscopes alone killed that idea pretty quick.
I then remembered an episode of scrapheap challenge from years ago where they had to carry open barrels of paint on a vehicle trying to spill as little as possible and that inspired my design. My idea is for a mass damped stabiliser that should be as simple and quick to construct as possible, no gimbals to make and make use of existing materials.

My design for a sprung mass damped stabiliser.

MD80 mount
Click to embiggen.
The Idea is the camera is attached to the top of a rod with a heavy weight providing the damping mass attached to the other end, which is then mounted by springs to a supporting ring with two connecting lines to attach to the kite's main bridle to prevent spinning.
The physics behind my design relies on Newton's laws of motion mostly, the 1st and 2nd laws.

  • First law: An object at rest remains at rest unless acted upon by a force. An object in motion remains in motion, and at a constant velocity, unless acted upon by a force
  • Second law: The acceleration of a body is directly proportional to, and in the same direction as, the net force acting on the body, and inversely proportional to its mass.

Basically what it means in simple terms for my design is.
1st Law: An object will not move unless pushed and a moving object will travel in the same direction unless pushed.
2nd Law: An objects acceleration is the same direction  as which it is being pushed and the heavier the object the harder you need to push.
So by transposing Newton's formula, Force=Mass x Acceleration - F=ma to a=F/m the more mass I put in the more force it'll take to move it.

The sprung mount should isolate most of the movement from the kite to the camera as long as I avoid the resonant frequency of the springs it should take some of the shake away. I may have to experiment with different sets of springs to find which combination of strengths avoids resonance. 

The counter weight will be several times heavier than the camera to make sure the camera remains upright and also the heavier the weight the more it'll take to make it move.
By having a heavy weight isolated from as much movement as possible I should get a stable platform to mount the camera on and hopefully some watchable video.

At this stage it is still very much at the initial design stage so any suggestions or comments are welcome.

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