At 01:24 PM 12/31/99 -0500, I wrote:
> The linkage was implemented using his kid's construction-toy
>kit, which included a couple of what I'm guessing to be 4:1 gearbox pods,
>for an overall mechanical advantage of 16:1
I shouldn't have called that the "overall" mechanical advantage. The truly
overall mechanical advantage involves a factor of prop diameter over wheel
diameter (maybe 2:1) and most importantly the propeller advance ratio
(maybe 8:1). Based on the observed wind speed, groundspeed, and
performance, I'd say that the true overall mechanical advantage was about
2:1 -- this is the a/c of my previous analysis. That would require quite a
big gear ratio (about 32:1 if my other estimates are correct, somewhat
bigger than my previous estimate of the gear ratio).