In this “quick tip” we will be discussing why it’s important to seal the hinge gaps on your control surfaces for your RC plane. Most ARF’s these days arrive with pre-slotted hinge locations which makes it quite easy install your control surfaces and get you into the air quickly. One area that is sometimes overlooked is the minor gap that is needed between the control surface and the wing to allow the needed deflection in the control surface. If the gap is too large it can lead to a plane that is quite “mushy” feeling when giving control inputs. Ailerons seem to be quite susceptible to this if the gap is too large.
A quick remedy is to seal those gaps with clear packing tape or seal them with the same color iron on covering if you desire a cleaner more finished look.
Click on the photos below for a larger view.
A sure sign that your hinge gaps need to be sealed: if you find yourself needing to increase the throw with the rudder or aileron to achieve your desired response. Also, if your control inputs feel mushy or delayed around center stick, this also a sign that the air flowing over the control surface is leaking through the gap!
How to Seal Hinge Gaps:
The best way to seal the hinge gap is to cut a strip of covering or tape approximately an inch wide. Then, fold the strip in half along it’s length in order to create a crease in the covering. The even crease will help ensure the covering is installed evenly. Next, deflect the control surface as far as possible and lay covering in the gap – pressing the crease as close to the hinge line as possible. Finally, seal the edges with an iron or if using tape press firmly to make sure it adheres well to the surface.
Once your hinge gaps have been sealed you will notice your plane flies with a much more positive feeling on the sticks when giving control inputs!