We tested lighting configurations using the wind tunnel model. Almost all of our lighting will be LED, so we used LED lights of appropriate size to simulate the effects on the model and environment at that scale. We found that the side lights were useful and helped present the size of the vehicle to oncoming traffic, but they produced a blind area at the nose. Using just a nose light, light levels to the side were marginal. With both side lights and nose light, the optimum lighting was achieved. We are now working with a LED manufacturer to produce the exact lights required for our use, starting with the headlights.
Meanwhile, the look was fairly cool, so we spent a few hours in the evenings just to see what could be produced. I hope you enjoy some of our renderings based on our testing of the lights, shown below.
The wing hinge metal parts were still at the machinist, so we shifted from the left wing to the right wing to continue building the prototype. Ron Burch prepared the two spars, main and auxiliary, to be bonded. Shown below, these two spars are to be bonded together using Hysol two-part adhesive. We had used one technique for bonding them on the left spar, and we tried a different technique on the right spar to gauge time spent and Hysol used.
It ended up that the technique of bonding the spars while horizontal rather than vertical (the final orientation of the spar in the wing) was the most beneficial- not so much in time spent, but in that we used less Hysol. Bonding the two spars ‘flat’ with tape on the side edges kept the Hysol in the bond area and produced less wasted Hysol. This was a good experiment to make, and we can use this to keep costs down while maintaining appropriate bond strength. Hysol is an extremely strong but hideously expensive aircraft adhesive. The finished spars are shown below.
The body shape has been finalized, and the side door and clam shell doors (in the belly that protect the wings when folded) were carved into the shape for reference. This will now go to the engineer for side check, and then to the machinist/mold makers for quotes to carve the ‘plug’. A plug is a solid form in the shape that you want to make the parts of. You then can produce molds by placing composite (fiberglass or carbon) material to it, letting it harden, and then taking the hardened material off for use as your mold. Your parts go into the mold, and come out the shape of the plug. The plug is important, as you will use it many times to produce many molds as the molds wear out from use. This will be our first look at the full sized fuselage (body), and we are eagerly anticipating this moment!
Usually, large crane-like computer guided milling machines are used to make this type of plug. We may use an alternate method of making smaller parts and gluing them together to make the whole, similarly to how we did the wind tunnel model. When we have pictures of this, we will post them as an update. In the meantime, below are images of the final shape showing the outline of the doors. We are using a similar technique to the automobile industry with the doors and sound insulation. Automobile doors have large overlaps where gaskets are used to keep the inside quiet. We are using this same technique on our doors, but using Carbon Fiber instead of sheet metal.