amc72,

There is more than one way to install CA hinges and what has been stated is great. Here is the way I do it. I first lay out the hinge with a center line, I then use two "T" pins and run them half way through the hinge on the line close to the edge on both side. Next I install the control surface until it buts up to the "T" pins. Now the "T" pins can be pulled out. Deflect the control surface to get the max throw and then carefully add the CA drops to the hinges.