RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
Hello Flycast,
The MAS 12 x 8 3 blades on a OS70 spin @ +/- 8500 rpm and on the Saito 82 @ 9700 RPM. The plane flys great with the MAS 12 x 8 3 blade on a Saito 82. As Tim (Krproyton) recomends, the 12 x 8 3 blade MAS is nice and scale but recomend to Maiden the plane on 13 x 6 APC 2 blade. I am also of this opinion since you need all the torque and power you have to lift off the ground when "unfamiliar" with its habits.
The OS 70 reports 1.1 BHP @ 11,00o rpm. You do not have 1.1 hp @ 8500 +/- 500 rpm with MAS 12 x 8 3 blades!!! your power is much less. Saito claims 1.5 HP @ 11000rpm and the power is not all there @ 9700rpm. You should try the MAS 12 x 6 3 blade on the OS70 and see if you are in the neighbourhood of 9500 +/- 300RPM. You will increase the torque on those props when lifting this 22 lbs +/- 1 lbs off the ground on the first flight.
See post 412 on page 17
I would go with 13 x 6 APC with the OS70 for the maiden, will give you speed & torque until you get used to it...which will not take long. It flys great.