Unless someone has run a tiny trainer through a wind tunnel with an instrumented balance, I doubt that you are going to be able to find that data. Good luck with the project though! One alternative to derive the curve through flight testing. You would have to have an AOA sensor and an airspeed sensor, with some type of onboard data recording. Then, fly at a constant altitude, slowing until stall occurs. Then you can use the data to correlate a lift curve. The components to do this are rather expensive though, but definitely costs less than the alternative! Sorry, wish I could be more help, but it is difficult data to get..
I initially played with a cardboard/FB wind tunnel but the design I used was on a site that was closed.
The wind tunnel provided a lot of quick relative data at the time and as I was not building rocket ships or high performance aircraft I did not need accurate scientific data, though it could be obtained if required.
if the info you require is not available on this site you could build your own Wind Tunnel out of scraps and take your own measurements.
Very interesting Hai Lee! A foamboard wind tunnel would be an interesting project for sure! I built a small one from plywood/plexiglass awhile back, but it would have to be pretty big to fit a tiny trainer in the test section! The balance would also be interesting to figure out.. Maybe a drawer slide attached to a fishing scale to measure lift? AOA could be set manually with a protractor..
My testing was relative and dedicated to airfoils, (I did not trust the effect of the bends in the FB for profile shaping as used in the FT FB designs at the time). I used wing sections with end caps/plates or winglets.
I used kitchen scales and a rod to the hold down platform. To reduce the binding effects of the induced drag upon the vertical tower within which my measurement rod to the scales was housed I simply added a fishing line to hold the wing from trying to move rearwards in the airflow.
My tests showed some lift degradation but actually very slight. For drag measurements I connected the scales and a weight to the fishing line and got some quite usable data.
As a side point the Plenum chamber on mine was just a pile of FB strips all fitted to give a lot of square tube like structures. I used 3mm FB at the time for the tunnel. Sadly all that Fb not being used was too tempting and most of the wind tunnel FB has since flown many hours.