UStik

Thanks again cygnet, that cleared it up entirely! As Evan said, it has to do with weight, and a powerful engine even adds to the snap-ability (nice word). But crucial ist c/g position. Following your specifications, I took the virtual Top Flite Taurus and set the c/g 1" back. The static margin is only 3.5% now, what I get as well when I balance a later pattern model, e.g. Kwik-Fli, for neutral behavior. Taurus would require negative wing incidence in addition to become neutral. Anyway, the standard static margin is even 15%, just to show why it's crucial. Engine power was left unchanged.

Now I can copy the (even very) good spinning and snapping in the simulator. By contrast, the stock Top Flite Taurus at 5.5 lb weight barely spins, and the 1" longer "contest" Taurus at 5.25 lb weight barely spins as well. And yes, the model is now balanced for slow flight and will grease in for landing. You can control the approach with power, without elevator.


Duane, I have to apologize, I was wrong about the Japan T2 (should have waited till I had it simulated). It flies noticeably better than the stock TF Taurus. Maybe it was intended to show a simple means how everybody could be up to the mark in early 1964 (dawning proportional times): Take a stock TF kit, build the wing with straight trailing edge and 3.25" dihedral instead of 2.25" (5.0/3.3 degrees), and set the c/g back by 2" to 6.75". As it turns out in the simulator, that gives a nicely balanced model, still quite stable but spinning and snapping even easily (due to "only" 10% static margin).

Top views of the 1" longer "contest" Taurus 1 (auction 1) and the "contest" Taurus 2 (auction 2) for comparison. Size your browser window to show 4 (thumbnail) pictures in a row.