This post is to give you folks an idea of what it takes to make foam wing from the drawings to the template to the actual cutting of the foam. I'm going to cut a Blue Angel wing and stab for 8178's project. Please feel free to ask any questions or input any ideas you may have with the purpose that everyone can simply see how this is done.

8178 provided me with a set of plans for the Blue Angel as well as drawing of the actual kit root and tip ribs for both the wing and stab. The first issue here is how much distortion was there in the copy. To find this out, you have to measure the tracings and compare them against the plan. The wing tip rib makes an excellent measurement here as it shows the complete rib and is the exact shape of the foam wing template in that area (after filling in the spar slots). The Tracing measures 17.85mm while the plan measures 17.7mm so we have a very small error here but one that will be dealt with. Here you must keep in mind that the builder (8178) is building from the plans... so I am going to adjust the template to fit the plans exactly. 1.5mm isn't much, which makes it just as easy to add that to the circumferance of the tip template. The wing root template is a totally different animal. MK makes wonderful kits that fit together beautifully but they have a tendancy to use 4 parts where one would do. Look at the picture of the plan, wing center section. Here you will see that the center of the wing is made up of two center rib pieces (W1 and W2) plus other parts such as spars/facings and braces. Our foam wing will have none of these so I must take the tracings I have, add 1.5 mm circumferance, and then draw in the lines to make the MK center assembly one big rib. Turns out here I have to add 3 mm to the front of W1, 2.8mm to the back and 9mm to the rear of W2. The center rib will be 31 mm when completed.

I also am posting a picture here of how the raw foam block dimensions are made. When you vew this drawing you will note that: C is the total root rib length, D is the length of the entire wing half, E is the length of the wing tip, A is the distance of forward sweep from a line drawn 90 degrees from the end of C, and B which is the distance from the end of C at the back of the wing. Please note that the drawing is of a double tapered wing while the Blue Angel is a swept wing design. It doesn't really matter if the drawing shape is the same, just that the dimensions are correct. Any extra time spent here makes everything else so much easier to do.... so do all that double and triple measuring before you break out the foam cutter. ... more to come....

Dan
Carolina Custom Aircraft