Yep, done that. The string on the canopy surface is about twice as
sensitive to yaw angles as the one on a one inch tall post. In other words,
the string on the canopy surface 'over-indicates' by about 2:1. I think
that's a good thing.

As another poster noted, getting the string placed exactly on the centerline
is the key. I've found that tailors cloth measuring tape is useful for
making those measurements since it won't scratch the canopy.

Despite the aversion expressed to drilling a hole for the yaw string, that
approach has some advantages.
1. It is a very 'clean' attachment with no tape blocking the pilots forward
view.
2. If the measurements are made precisely before the hole is drilled, the
positioning will always be exact.
3. The string is easily removed/replaced for cleaning and polishing the
canopy.
4. There is NO chance of the string blowing off in flight.

Note: If you decide to drill, you MUST use a sharp new drill made
specifically for drilling plastic.

Bill Daniels

"Tony Verhulst" wrote in message
...

I've always felt (but have no evidence) that positioning a yaw string on
the canopy is not optimal, and that you really want it in clean,
undisturbed, air (yeah, like the 2-33). There could be 2 problems with the
canopy mount. One, it is flush with a compound curve surface and who knows
that the air is doing there. Two, it is in the boundary layer between the
canopy surface and the airflow and who knows that the air is doing there.

I wonder if any one has experimented with a "normally" mounted yaw string
and one placed on a post several cm higher.

Tony V.