MAAA Wingspan

40 41 WING SPAN NOVEMBER NOVEMBER WING SPAN MAAALogo. The balsa skins were then glued- together ready to glue on. We also made cut-out provisions for the servos in the wing. The skins were taped together at the trailing edge and then opened out to have the resin applied and, at this point, we laid a 30mm-wide strip of light cloth across the trailing edge joint in the balsa. A few carbon toes where also installed as spars, the wing cores were placed into the skins and then placed into a vacuum bag with 4lb of pressure and left to cure. (image 5G wing in vacuum bags). When dry, they were removed, trimmed and sanded to final shape. Image 5 and 5A (foam wings, and wings sheeted) The trailing edges were then trimmed off, faced and the hinges etc for the aileron/flap installed (image 5H aileron detail). Note that the hinges are set back into the aileron and a small cover is glued into place to close the gap between the wing and aileron. We have then moved onto the construction of the tail feathers and, for this, I used some very thin plywood as a centre spine for the outline and sheeted them in balsa. This gave me a strong, rigid, lightweight tailplane. Weight was critical here because, given the short nose moment of the model, we had to keep the tail sections light, but still strong. Hard points where installed for the tail wire rigging using sections of 12mm dowel Image 6 (tail feathers) Next element was to sort out the cowl. A simple pattern was made from foam and parts from an older cowl (a Cap 20L made by Peter Goldsmith many years ago, before he moved over to the USA). This was then filled, sanded and the mould made using fibreglass. Images 7-9 (cowl pattern, cowl mould started, finished cowl) When these were done, we had the opportunity to install the wings and have out first look at the model. Progress has moved on to all the little fiddly bits that need to be fabricated such as the wing struts, wire bracing attachment points hinges, control horns, servos, door hinges and latches. All these little bits just add to the finished model. One of the challenges was the huge windscreen, which is 300mm wide and 350mm long, with some complicated compound curves. Again by asking other modellers, and thanks to Russell Mitchell from Aeroscale , I made a pattern for the windscreen and he is now making the windscreens and side windows. This is just an example of how we all have skills to share to help make these creations of flight. Image 10 (windscreen pattern) Image 10A (interplane struts detail). These were made using 4mm Rivet Nuts inset into dowels in the wing and secured with a bolt from the bottom of the wing. These are held in place with epoxy and, as you can see from the finished shape, (Image 10B) , provisions were also made for the rigging wires to be installed and attached to the bottom and top of the struts. With all the elements built, sanding has commenced, the wings will be covered in epoxy and 20g glass cloth for a smooth, strong finish. The fuselage will be covered in polyester fabric and dope. This is a technique that a lot of people have asked about and I will include photos and details of the process including the painting. There are many techniques involved in covering aircraft and, like all things, this is a combination of many very experienced modellers’ learnings including people such as David Balfore and John Armarengo, and also a number of modellers who are no longer with us. We need to practice these skills so they can be passed on to the next generations of modellers as they have been passed on to us so, if you are interested to know what I have learned from others, and experience, then read the next issue to find out. Image 11 Above (ready for final sand and covering) Article and images from Tim Nolan “Wingspan is our publication and if you would like to see more examples of projects, or how people go about tricky modelling tasks, this is the perfect forum so please drop me a line and we can find modellers who will be more than happy to share with you how they build the various elements of a model. ”