It is not advisable to use small metal or plastic clevises with a plastic pin on either of the primary controls i.e. "elevator or ailerons".   They are fine for use on rudders and throttles unless you do a lot of 3D stuff then you might not want to use them on the rudder.

The DuBro 4-40 clevises work fine but they tend to break after you take them off and on a few times.   If you use a clevis that has a bolt for a pin be sure to use a lock nut. 

PUSHRODS

fiberglass arrow shafts or wooden dowels make great pushrods.  Be sure to brace the pushrod in a couple of the fuselage bulkheads so they don't bow under load.

ELEVATORS

If you fly hard and put a lot of stress on your model and want precise adjustments to your control surfaces you might consider the split elevator configuration dividing the stress between 2 pushrods and control horns. It also allows you to adjust each side separately.

You can use 2 4-40 rods on the end of your arrow shaft or dowel. They are bent outward, looking like a sort of "Y" and exit the fuselage through a slot on either side. You use a control horn on each elevator half and these elevator halves are not connected together.

Another method would be to use two separate pushrods and 2 servos. Each one has a pushrod that is connected to each side of the elevator. It is important to have servos that are the same speed and movement. The bigger the plane the more noticeable mismatched servos will be. 

RUDDER

For the rudder it is really a good idea to use the pull-pull system as the rudder needs plenty of travel.  Any slack in the servo gears or in the pushrod connection will result in a large amount of slop in the rudder. The pull-pull system allows you to tighten up and remove any slop in the control system.

AILERONS

The ailerons are a different setup.  Use a servo in each wing with a metal 4-40 rod going straight to the control horn.  This system gives the least amount of slop and any kind of slop will lead to flutter 

THROTTLE

Golden Rod or cable can be used on the throttle and is great for routing around and through the gas tank and so forth.

ONE SERVO COMMENTS

TWO SERVOS COMMENTS

1 Pushrod on each servo (Split Elevator)