RE: World Models Ultimate 40S
I've been flying mine a lot the last week or so. It's excellent. Yesterday we had enough wind that a number of the regulars at the field sat out most of the day. I was trying to get 'em to fly by showing them how the little baby would do "hover landings". Must have done 5 or 10. Mine has no tendency to snap out of anything. Look up the aileron rigging posts.
I'm flying an OS46AX on mine. It will go straight up for a long way with either an 11x6TF or my favorite, an 11.25x5. That favorite, I make by trimming a 12x5 TF wood. I put the raked tips on it. Measuring the diameter to the middle of that tip. I worked out the diameter measurement through experimentation. Got nothing but gut feel for it's suitability. But I have found that a number of my other 46size airplanes with the OS46AX like prop fans of 11.25" to 11.5" diameter.
I use 10% fuel that has some castor in the oil mix.
Mine is a sweetheart.