Check the elevator tracking: Take 2 straight edges, I use balsa sticks, about 12" long, something like this and lay one on each elevator half IN THE SAME location. If you have corrected any elevator flatness issues as discussed before, the stick will lay flat on the elevator half. If it does not you should correct this now. I glue 2 nickels on one end of each stick for weight to hold the balsa on the elevator. Start with the elevators level, place the balsa sticks on top of each elevator. (an interesting thing to do is place them on the SAME elevator half – outer end and inner end - to see how level the elevator is from one end to the other - this reveals sanding imperfections when you build your own plane). With your radio on, and the balsa sticks on top of the elevator halves, say in the middle of each one, pointing away from the elevators, stand at 90 degrees to the sticks and view if they are parallel - they won't be if you have not done this before. Screw the clevis in or out on one side to make the stick parallel. Now comes the fun, slowly raise the elevator halves by pulling back on the transmitter stick while watching the sticks from the 90 degree position. Your job is to make them track parallel all the way up – you are mostly concerned about the end point – full up throw. This will be an indication of your control arm placement. If the arms are not exact, and they never are, one elevator will raise more then the other – ie, the sticks will not be parallel when you reach full up throw. To fix this, screw in / out on that arm which will raise or lower that elevator half. You are not turning the clevis here, but the up/down position on the control arm. Note: this is why you don't use the pre-formed plastic arms with predrilled holes, there is no fine adjustment. Recheck the center and adjust if necessary. This is an easy to get in alignment at this time. Once this tracks the real fun starts. Turn the model over and do the same for the down elevator. Note, you can not push down at this time to check the down throw - when the model upright pushing down is not an indication of 'what the air sees' during down elevator, you must turn the model over to check the down elevator. Lay the sticks on the elevator again, and pray they are level to start with. They should be close. If not, lay a thin strip of clear tape at the outer edge of one elevator to make the sticks parallel. This tape will go along the outer edge of the elevator all the way across the back of the elevator. Use 1/4' or so and if the elevator is really off, taper the tape with a few layers.. the 1st layer being 1/2", then 3/8" on top of that, and 1/4" on top of that. You should now have parallel sticks again on the bottom of the elevator. (At this time you know your elevator's are aligned the same at the center, and full up). Now push down elevator and watch the sticks again. If they track you are lucky, if not, BEND ONE the control arm a little to bring the throw into alignment (you are bending the thread portion of the control arm now), this will of course ruin all previous settings, so you start all over from the top of the model and do it all again. 2-3-4 times of this will get the elevators perfect, tracking correct in both the up and down throws. This is worth the time. Your model, assuming your wing is straight, each aileron has been adjusted correctly, the engine offset is correct and there is no heavy wing, will now pull up straight every time.