Now, let’s talk about proper linkage setup. Many advanced airplanes take advantage of ball-links to attach given pushrods to a servo arm, control horn, etc. Using ball-links in these areas guarantees to improve linkage geometry and allows a given surface to move freely. While using a clevis works if servo and linkage geometry are correct, if there is any misalignment whatsoever, using ball-links may be needed!
Next, let’s talk about my personal setup. On my 35% and 40% aerobatic models, I always use Hangar 9 4-40 Titanium Pro-Links and Du-bro 4-40 Heavy Duty Ball-Links. With that being said, I am often weary that a given ball-link can become undone over time and “pop off” the ball that it snaps onto. Resulting, I use a washer between the 4-40 socket head bolt, the ball-link, the ball-link spacer, and the given lever (either a servo arm, throttle arm that is secured to the carburetor, etc). Doing this will always leave me with the “peace of mind” I need to focus on one thing, flying!