On Dec 29, 5:19*pm, brian whatcott wrote:
T8 wrote:

He then mentioned that way back in the early days of flying they would
simply tape a string hanging from the ceiling to act as an artificial
horizon.
It's not April 1 already is it?

Just put a mark on your canopy and spit at it. *If spit flies left of
target, you are turning right and vice versa.

-T8

NOW you're talking.
There was a D-I_Y autopilot design which used a blower tube streaming
air onto four thermistors arranged pairwise-differentially. This gave
pitch rate and yaw rate, or if mounted skew, inputs on all three axes.
These days, a three axis acceleraometer goes for $25 and rate sensors
for a little more... * One well known Arduino project ["ArduPilot"]
offers the guts of an autopilot suitable for driving R/C servoes, which
will easily fit in a medium size model plane. I expect this could easliy
fit in a homebuilt...

Brian W

One thing I think would work is pitot tubes on each wing tip connected
to a Winter type variometer with the vario rotated so the needle
pointed up. Air would flow from the faster wing tip to the slower one
through the vario which would show rate of turn. It's the only "non-
gyro" rate of turn instrument I can think of.