Hinges can be a tricky part of some models and trying to minimise the gap between trailing edge and control surface can be the hardest part. On some models even a modest gap can cause no ill effects and some planes (the Junkers Ju52 and Ju87 spring to mind) there is a huge gap. These types however are usually slower flying planes, not required to perform any kind of sharp manoeuvres or aerobatics. On other aircraft types, this gap can be disastrous causing reduced control authority and worse still total lack of control as the air passes through the gap and not over the control surface. This is particularly apparent on high speed aircraft and precision aerobatic types. Top hinging ailerons has one or two advantages over connecting the flying surfaces with the commercially available hinges. Firstly it is far neater to look at when done well, secondly it seals the gap and therefore improves flying characteristics especially at low speeds and thirdly it’s actually faster than normal hinging once you get the hang of it.

To start out you will need a sharp knife or scalpel, a long metal ruler or other straight edge and a heat sealing iron. You will also need your wing and ailerons (or tail and elevator/s), your choice of Pro-Film for the hinges and a clear working space. The first thing you need to do is to cover the ends of the ailerons and the sides of the recess into which they fit using your chosen final colour. The anchors and hinges are shown in red for this article for clarity but can be any colour you choose. Underside Anchors First Using figure 1 as a reference, lay the aileron, inverted on the top surface of the wing. Now using three postage stamp sized pieces of Profilm attach the aileron to the wing. Use one at each end of the aileron and one in the centre. This anchors it in place when the full hinge is applied. Take time here to ensure the edges are flush and the aileron is in the correct position to allow full free movement.

Topside Next Next deflect the aileron to its full down position (Fig 2) and put three more postage stamp sized pieces of profilm on the top.

Full Length Hinge Once attached with the anchors on the top and bottom put the aileron back in its original folded back position and put a full length one inch wide strip of profilm over the top of your anchor points. (Fig 3) This strip needs to cover the entire length aileron. Next deflect the aileron down and put a one inch strip of profilm along the top surface and your hinge is complete. Again make this fit as exact as possible over the whole length to avoid leaving gaps. When you come to finish the wing, simply cover over the hinge on the top surface. On the bottom just cover as far into the recess as you need to so that the coverings overlap. Throughout this article I have been talking about Pro-Film as my covering material as it is the only covering material I trust for this purpose. Other coverings will not stick to themselves well enough to make them safe. I have models that are eight to ten years old that were hinged this way and they are still going strong.

Article by Martin Johnston Of Freestyle Models
for Bumpy Green Model Aerodrome
October 2004