Guys,
I finally got around to doing some work with the pusher props and long story short I like them. I have been flying my Excitation (600 sq in, 60 oz, AXI 2826/10, 4S1P 3850 mah, 9000 rpm, 65ft C to C, 5.0 lap) ship for about 8 months with a normal APCE 12x5 (repitched from 6)tractor props and have tried different blade widths (cut down 13") and some of the old standard wood "46" size props. In the end I always came back to the 12x5. I have been curious about the pushers and decided that electric is the easyest to try it on (just switch any two motor leads and it reverses the rotation direction). The one challenge was getting the pitch gauge set up to read the reverse pitch. What I do with my pitch gauge is to clamp the swing arm at the pitch I want then check both blades, this eliminates errors for repitching. For me I just set station 9 on the 12" props (around the 70% length) and pitch the whole blade from there by heating the root and tweeking (you get a feel for how much pretty quick). Since the reading are all relative you get a starting point then adjust the swing arm for more or less as needed.
For the pusher what I did was with the swing arm clamped for the pitch that I have been flying, mark a line the full length of the plate on the back side of the gauge indicator plate (the part with the numbers). This sets the pitch point. Then I disassembled the swing arm and gauge plate and installed it flipped backward so that the swing arm and gauge plate are reversed from the normal position (the bolts holes all line up perfect just that the heads will not be flush). Now you can pitch the prop as normal to the same angle as the tractor prop. This worked and I hit the same lap time at the same rpm as with the tractor prop.
I flew the ship back to back with the tractor then switched to the pusher. The first thing I noticed was that the ship liked to hug the ground a little more on the take off roll. Some of the flap tweak was off a little because the torque reaction is opposite. The inside maneuvers were just fine the big gain was on the outside corners. It just feels very, very solid. For me, I liked the solid fell on the outsides and the top of the vertical and hourglass. This is worth trying but you do need to check the pitch as it may not hit the same mare from the factory as the tractor prop.
Best, Dennis