Hey guys, I bought a twist .40 and it has a brand new saito .72 on it. The pro that set the plane up has an APC 13x4 wide blade on it. Is this prop going to be okay? Is it going to turn to many rpms and shorten the life of the motor. I am running 15% in it. Thanks for the help. Matt

that prop is good

You'll be fine with that prop.

Ken

G'day Mate,
Check out this Saito site, http://saito-engines.info/prop_sizes.html

the prop is made for pure pulling power. It will pull that plane out of a hover with authority though it will not have a high end speed but this plane is not built for speed anyways

As I read in the prop charts I read these are the right sizes for your 4 stroke .72CI engine.


0.63-0.72 12x7, 12x7~9, 13x6~7, 4-Stroke Glow, 10000~11000rpm

Mody

The above prop numbers are the factory recomendations for sport and scale flying. How do YOU want to fly your Twist? The 13x4 will be good for 3D flying but based on the factory numbers I would even look for a 14x4 as a possible prop for even better 3D performance. I experiment with props but the down side to that is I end up with props I don't use

What is 3-D flying? What are some good characteristics of a good prop such as 11-4,11-7?

Take a minute and watch the video I have linked below. This is 3D flying. You use the engine and prop to fly the plane more than the wing for most of the manouvers. Control surfaces on planes designed for 3D flight tend to be larger as well as they rely hevely on the prop wash for control as aposed to airspeed flowing over them.

http://www.ohiomodelplanes.com/62kat...t70aerofun.wmv

An prop 11x4 would have more pulling power and spin up faster where an 11x7 would have a higher top speed but might take a little longer to get to it while the prop spins up depending on what engine you have it on. I have used an 11x7.5 on an OS .46 FX and an OS .50 SX and the diference is amazing. The 46 flys with it fine but the 50 uses it more efficiently. So for speed with my 50 I use an 11x7.5 and for 3D I use a 13x4.