Hi all
I'm biulding a train air 40. Built up construction motor is a OS .46 FX. The motor mount is mounted on the fire wall. How can I tell if the motor is mounted straight or if it is mounted on some angle, LEFT OR RIGHT.
Thanks.

Catually it should point just enough to the right that you can see it when the prop is on. Trainers typically have 3 to 7 deg right thrust, to counter torque and what is called "P Factor." (P factor is only a big deal when the nose is pointed up a fair amount compared to the line the airlpane if following, as in a tialdragger starting its take-off run.)

A good way to check the angle is to put a 12 inch section of yardstick on as if it were a prop. You can then compare the angle made between the stick and the fuselage sides. Most trainers, in the forward part of the fuselage the sides are parallel, so a grade schooler's 30/60/90 triangle will easily tell you if it is straight when trying for 0 right-left thrust angle. With the prop parallel to the ground, when the triangle is on the left side of the airplane, the 90 deg corner shold meet the yardstick and if the base is appx 3 inches.. ther should be appx 1/4 inch gap from the 60 deg angle corner to the yardstick. (this does assume the fuselage sides are parallel... and its a common trainer looking for appx 4 to 5 deg right thrust)

The thrust line can be off and the plane sill fly... you'll just need different rudder trim at different throttle settings.

Great thank you. I wish we had this much help 15 years ago when I was just starting to fly 4ch. Starting again and this time I think its going to be fun.