Yesterday I did a short flight to evaluate the mount I made for the Garmin Aera 510 GPS/Satellite Weather system I bought. The mount isn't perfect, but it is good enough for now. The Aera comes with a mount designed to attach to a control yoke, which is useless for me as my aircraft has a control stick, not a yoke.

I disassembled the yoke mount and kept the part that the Aera clips into. I attached this piece to a small piece of aluminum, and bolted a mount for a 1" RAM Mount ball to it.

I have an unused 2 1/4" instrument hole over on the right side of the instrument panel (long story). I made a blanking plate with a 1/4" hole in the middle in the centre, and bolted another RAM Mount ball there. A long mounting arm goes between the two balls. I forgot to take a picture of the whole thing assembled.

The weakness of this design is that the loads on the ball mounted to the instrument panel tend to unscrew it. I put an internal locking star washer under it, and torqued it down very tight, but I doubt that will work forever. I've got an idea of a better way to secure it, but it will take some time to fabricate the next version.