12.25x3.75
or
12x4

for engines os 46 fx

When selecting props you need to look at the diameter and the pitch. (The pitch is the theoretical distance traveled with each revolution: ex. a 14x4 prop has a 14" diameter, and will traves 4" with each revolution)

Smaller diameter with higher pitch gives you more speed, and Larger diameter with smaller pitch gives you more thrust with less speed (great for 3-d).

For 3-d flying you usually want a prop with a large diameter, and a small pitch. So look at your engine's recommended prop range, and pick the higest diameter, and the lowset pitch. For my SAITO FA-80, I am using an APC 14x4W (wide blade). There are a lot of articles on this subject if you have any more questions.

I hope this helps. --Dan

The 12.25 x 3.75 usually works better.

zonk

depends at what temp you deep fry it?

lol

id go for the 12.25*3.75 APC. cant go wrong with thaty

even batter idea get both and see what you like best

There's something about that 12.25-3.75 prop that works great for 3D. The blades are wide. It hovers my Ultra Stick 40 all day long with the 46FX. I think my RPMs are only about 10,600 to 11,000. With a 10-7 it would turn almost 12,000. Anyway, with a tuned pipe or Tower muffler you might get the peak more near 12,000 with the 12.25-3.75. Higher nitro would help with the transition and peak RPM's. I'm only running 15% Omega.

My OS46fx with tower muffler and a 12x4 apc will turn at 13400 at full throttle, and it will make my fazer disappear vertical from a hover in no time yet stills allows me to fly so slow that it will fly backwards in a light breeze.