sctcrash...for what its worth I would recommend a 90 oz in servo for rudder...I would also recommend running 6 volt battery pack..especially if your using digitals ...digitals use tremendous amounts of power over standard...the rudder is a very large control surface, it needs lots of power to drive it properly and without slop..follow great planes suggestions in the manual ..this plane comes out to right around 6 lbs, a 46 engine will not do it justice..power to weight just is'nt there..don't get me wrong it will fly with a 46 but it would be lacking for my liking ..and one other thing ...make sure you check the mechanical advantage of the the servo arms..if you don't get enough throw with standard arms don't move the linkage into the closest hole on the control surface(horn)..I think that some of the rudder troubles have been a high torque servo on the rudder and set in as close as possible to the control surface and the servo is ripping the rudder out ...(MTC) if you don't have enough throw buy longer arms! Dubro makes extra longs for pretty much all servos manuf.

good luck with build! You'll love it ..just like the rest of us !