The Jello Wars
When using an HD camera to record on-board footage, you may find that the video is of bad quality, due to an effect unofficially called "jello" or rolling shutter. This problem exists especially in multirotors, and is usually cause by bad quality motor bearings, bent shafts, unbalanced props, motor bells etc.
Careful balancing (static and dynamic) of all those parts should fix the problem. But sometimes jello just doesn't seem to go away. After trying many different solutions (more than 10), Chris is presenting the 3 most effective here.
Fuel Tube Method (Recommended)
The method that has permanently solved my jello problems is made of two wooden "plates", bbq skewers and fuel tubing. The skewers are glued with CA to the plates, and the tubes are just pressed onto the skewers (it is very tight).
A few notes:
1. This mount is known to work if both a mobius and a board cam are on it. If only a light camera is used, the length of the tubes may have to be adjusted.
2. Since making it, I have shortened the tubes to make it more tight. It still performs perfectly!
3. The tube is not actually fuel tube but some rubbery tube that I found at an art shop. It's probably used for some parts of a pressure-spray painting, but RC fuel tubing should do, too.
Stranded Wire Method
Here's a solution for the Mobius camera:
I made this twice, once with 1.6mm rope wire and once with 1.1mm. The thick one is too stiff for the little (and light) Mobius camera.
I settled for 1.1mm thick, 8cm long strips. Longer and it's too wobbly. Shorter and I still get jello. So 8cm is ideal for a mobius on top.
This solution is very light and cheap. List of materials:
- 4 x 8cm rope wire. It's used for bicycles' gear change mechanism. Cheap. 2 eur for 2 meters! See pic
- 8 x small zipties
- 2 x plywood plates. dimensions to fit your purpose
- 8 x small pieces of double sided tape. The 3M indoor/outdoor is the best due to its moldability.
The zipties hold the wires in place. The tape is used to increase friction, so that the zipties can grip on the wire better.
Works well for me!
WARNING: If you try performing extreme manoeuvres (acrobatic flight) or Autotune in Ardupilot, you will run into trouble! The Mobius camera acts as an extra pendulum and confuses the flight controller. I had 3 major crashes due to this, although I had previously flown the same setup for hours, and didn't have a problem as long as I was flying easy. I'm also afraid this can happen even if you fly normally but there's a lot of wind.
Gigantic Zip-tie Method
A different solution, with big zipties, is shown here. In my tests I found out that while this makes jello disappear, it introduces a lot of movement to the camera, so it's degrading image quality.