I'm new to this R/C fun and love it. i purchased a almost built old 172 at a garage sale. .25 size, finished and tried it out. on take off the plane rolled to the right and smacked the ground. fixed it. to make things short it did this everytime, untill the last fix, i mounted the engine straight up with no angle to the right. it only had about 2 degrees to begin with. but with the engine straight, it took off straight. whats up with that. everything i have read says you have to have some angle for for torch. any thoughts. rick near elderton

the plane probably wasnt balanced and by changing the angle of the engine that fixed it

Does the firewall already have the angle in it or not?

Check the lateral balence.

I can't imagine changing the engine mounting position would cause that big of a change. Did you check trims, reversed servos, etc. or as mentioned above, lateral balance.

Sounds like you changed the thrust angle. The prop (an airfoil in its self) thrust will cause one side to pull (lift) greater than the other, that is why the engine is offset to equal out the pull. The vert. stab or ailerons or wing may be warped causing too much deflection in the airfoil. This deflection, plus the thrust, would cause the plane to go right and changing the thrust angle to 0 or - (left) balanced out the difference. You should check to see if the vertical stab and rudder are strait, that there is no difference between the airlerons when at neutral, and that there isn't any warp in the wing. If any one of these problems correct themselves, and they could due to temperature or flying conditions, then you will have a plane that is very hard, if not impossible, to control.
Scott

I'm going to suggest the plane didn't "roll to the right". I suggest you pulled it off the ground too steeply, and it stalled, which made it snaproll to the right.

I suggest that coincidentally, after you changed the mounting, you were more cautious in taking off, and let the plane gather some more speed before it lifted off. I'll bet you could take it off now, cautiously, with lots of right thrust. These things will take off and fly quite well, with or without a lot of right thrust.

Just my 2ΒΆ worth, good luck!
Dave Olson