I think i have two type of hinges on my plane. On the ailerons I just have the flat plastic ones (as seen in the pic below). But on the elevator and rudder it is a flat plastic on with what looks like a door hinge.(with the pin that locks the two together in the middle. (it's hard to make out in the last two pics. You can see in the last pic how the bottom hinge pull right out if i pull on it but no other hinges on the plane pull out. I could do the pin idea on all of the hinges since i know the ends are plastic. But minnflyer's example only shows putting the pin on one side of the hinge. don't i put it on both sides?