ORIGINAL: gooseF22

Use a ball on one end, the servo should center at the middle of the hole, and make the linkage at 1/2 flap from there. In other words zero should be a little more than takeoff position. The rest of the adjustments can easily be done in the radio.

Get an ammeter and use it when setting up flaps, so you will be able to nail the lowest current flow exactly. just plug it into the receiver between the battery and receiver and minimize current. Also if you have them separate channels, you will easily be able to match them. IF on Y cord, it takes more mechanical matching.

I use matchbox's alot on my flap setups. they make it really easy. IF it binds on both ends and you cannot enlongate the hole without having the clevis go inside the skin, then get a longer servo arm (use HD) arm. almost any good metal servo can handle flap loads if you dont put them down at 120mph..