looking for unwanted wobble

Recently I watched the flight test video “Laser balancing props” and loved the idea how you could visualize hidden vibrations.

So I copied the idea and built a rig to look for hidden vibrations caused by turbulence on different shaped quad arms

I built a rig out of bits of old greenhouse,( which as it happens make good quad frames) and rubber bands to try and simulate a quad arm as it self corrects.

I then hung it over a table to try and cancel out as much ground affect as possible and used the laser trick at a different angle to try and catch any up and down movement . 

After looking at images of aerodynamic shapes I was surprised to see exactly how much drag and turbulence there is even on round tubing, so I went for the teardrop shaped arm which seemed to be the most practical to copy and compare it to a square shaped arm.( the most streamlined shape is called the symmetrical aerofoil… I think).

I used nylon kite string round a plastic strip held in place with hot glue to get the shape. Then finished it off with ca glue and tape.(by the way that nylon kite string and ca glue combo sets like steel  I`m Sure there`s a chemical reaction going on) .

Anyway I made the square shape out of card held in place with rubber bands. All I had to do was cut away the rubber bands to compare the two. On the first video you can hardly see any difference.

But add the laser and you can clearly see turbulence and bouncing in-between the different rates of throttle. I wonder if this would be useful in FPV getting rid of unwanted wobble.

I can’t help notice, but even in the most expensive multicopter frames there is little or no consideration for aerodynamics directly under the props. The only place where it`s really needed.

I’d love to do a before and after using FPV to see if there is an improvement. That`s a little beyond my reach at moment. But I will get there. Please let me know if I`m way of the mark here or if there`s anything in it.