Shanksow,

Think of the "thrill of victory" when you get your Sabre to fly well knowing that it was your hard work that made it happen. Sure, it is possible to just buy a BVM Sabre or some other well established ducted fan aircraft and be virtually assured of success because all of the design tweaking has already been done but, there is nothing like the thrill of pioneering your own tweaks to produce a better flying craft. Of course there is always that "agony of defeat" thing but, as they say "nothing ventured, nothing gained".

I think what t33jetman means by "half moon" thrust tube is "partial" ducting of the lower half only. Don't try to duct around the complicated stuff up top. Looking at t33jetman's pictures of his ducting, it looks like his ducting is actually more than a half moon. Going clockwise from a rear view, I'd say it looks like his ducting starts at 3 o'clock and ends at 11 o'clock. This avoids all the complications of the control rods and such. From my test stand experience, I can say that the 3 to 11 o'clock area is the area of the fastest efflux from the fan because there are no obstructions there (head and pipe), and would therefore benefit the most from ducting.