Should You Run Servo Horns Or Direct Couplings In Your RC Planes?

When purchasing a servo motor, it often comes with a selection of plastic horns for use in various projects. Many hobbyists pick a favorite horn to use, while others might modify these horns or even skip them altogether, opting for a direct drive setup instead. In a new video, Dynamix Systems discusses when using direct drive can be a more advantageous choice, particularly in the context of aero modeling.

The video highlights some of the downsides of using standard servo horns in aero modeling. While stock servo horns are convenient and easy to use, they can be bulky and awkward. The horns and their associated control linkages often protrude into the airstream, causing increased drag and making the setup less aerodynamic. Additionally, these protruding parts can easily snag on objects, potentially damaging the servos or the control surfaces they are attached to.

To address these issues, Dynamix Systems suggests using direct shaft couplers as a neater solution. By coupling the servo directly to the axis of motion, it allows for a more streamlined design where the servo can be hidden within the wing or tail surface of an aircraft. This approach requires a bit more precision in both installation and design, but it greatly reduces the chances of parts snagging or getting damaged. It also minimizes drag, which can improve the aerodynamics of the model if executed properly.

For those considering this approach, Dynamix Systems notes that shaft couplers are key to a successful direct drive setup. These couplers can either be fabricated manually or purchased online, making the modification relatively accessible for hobbyists looking to refine their aero modeling projects.

Read more: Should You Run Servo Horns Or Direct Couplings In Your RC Planes?