Update on this issue.

Problem was improved by adjusting the ailerons so their neutral position was
1/4 up (rather than perfectly flush) but the problem was totally solved when
Bud Clarke (who has built a number of aircraft with his company AirRyder in
Helena Montana) came home to Canada and visit family and friends last week.
He spent some time with us and now our controls are great, on the ground, at
low altitudes, and at high altitudes.

The good news is that it was all adjustements inside the cabin, so hopefully
what we learned will help others.

What the real issue was that as we pressurized the cabin, the bulging out of
the cabin causing a signficant tightening on the two ends of  the control
rod as the hinge points turned inward slightly thus causing the binding.
This caused the force on the aileron control to become excessive (caused A/P
problems too as forces would change when pressurized compared to
unpressurized) and the fix was to take out some of the spacing washers to
increase the amount play in the control rod movement on the ground.

Boy is it ever smooth now, even at altitude.

Conclusion.  Subjective measurements have limitations, and I suspect a
number of other IV-P's flying could reduce their stick forces signficantly
by learning from our experience.  Ideally, I still hope to have a small
pressure guage developed which would allow the mearsurement of stick forces
as this would allow a much safer testing prior to first flight, both
pressurized and unpressurized.

Gerry Leinweber C-GLFP