Symptoms: Flamewheel 450 twitches down on one arm, not the same every time, and sometimes, instantly flips over as if one prop suddenly lost power.

The cause is a quality control issue with the bullet connectors on the motor and the sockets on the Opto speed controller.

The bullet connectors have a cage with a split. The problem is that when inserted, the split closes but the inside diameter of the now-closed cage is larger than the pin on the male bullet connector. This leads to weak or intermittent contact, and is evidenced by a little slop in the connector when inserted--it can easily be rotated or pulled in and out a fraction of a millimeter as if loo

se.

The fix is twofold. First, one must use a small wire cutter to snip one section of the cage so as to widen the split. The second is to make a narrow strip of thin (0.002" thick) copper. Fold the strip, insert the modified connector into the strip in the socket, and no more problems. The photo shows the strip and modified connector. Every one of the 12 connectors on the Flamewheel 450 kit I bought in December of 2012 has this problem.

Here's a simple servo-controlled very light GoPro mount for any UAV. I have machine tools to make this, but you might be able to do it with simple home tools. The real trick is a direct connection between the servo and the camera rotator, and to use a control link ball (left side in photo) so you don't need to hit any dimensions perfectly.

Remember, if you bend aircraft aluminum, you must heat it to 530C for 15 min, instantly dunk it in water, and then do the bends within a day or so, otherwise it will crack. If you warm it up to 150C for an hour later, then it will return to full hardness.