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D-WAV II refinements
The last D-WAV I contributed to some modifications in construction and to improving
the glide flight path. With this static model, the new discoveries made from the
last models where implemented. Improvements where made to the exhaust, the winglets,
and foil profile to share the same angle of attack.
More care was taken in setting up the correct height of each component with support
posts. This ensured the foils where at the shared angle of attack.
The steps to improve the exhaust was first by making a plug of the “Duct-Vane“ exhaust
and use it to assist in the molding paper into shape. I discovered by wetting the
paper at the folding point it was much more malleable at taking the shape. I let
the paper dry before I started to use one part water to one part carpenter glue mixture.
Placing the new piece of paper into the mixture and wiping off the excess, I then
apply several layers with a smaller version of the fist, about four layers for this
scale. As I place each layer I squeeze out excess glue by rubbing it with a smooth
surfaced tool like a metal tube. This ensures that there is no air gap between each
layers and makes for a better bond. When dried the glue acts as a reinforcement
agent, thereby a rigid structure is created.
The Duct-Vane is constructed of three parts the inlet the top exhaust shroud and
the bottom shroud joining piece. Using the plug as the guide for assembly the process
is much easier and accurate.
These methods will be used as a guide line to construct the next test plane. I am
looking forward to making this work.
The model
A note to my readers, this model design in progress, it is not an accurate process. A design on the Fly, pardon the pun. But the task here is to build a flying model with the ability to have a steady glide path, and to prove under power it would be forgiving, a gentle handler. As demonstrated some results are, at best useless, and the next step is improving on the intended result. Some cases the design process serve at getting the general shape without considering the structural integrity; of course, this would constitute a rebuild, to improve the structural integrity. So goes the theory…
I had an idea to build with Styrofoam block for the body and a buildup for the wings, the Duct-Vanes with my paper technique (paper marshier). I built the outline of the contributing profile for the body halves out of Fence wire strand, they soldered well. After assembling the wire profile, I pinned them to a Styrofoam block with the appropriate dimensions to the desired shape. I cut the pieces with a hot wire cutter, and glued them together. Then I built the Duct-Vanes and the wing struts. When assembled, I decided to check the weight. This proves the construction method was too heavy. An alternate wrought has to take place.
Foam block gave way to Wood
I decide, to a build up from scratch with balsa and the Duct-Vanes with my paper technique (paper marshier). As the construction went on I began to get dissatisfied with the way the wing where turning out. Not to mentioned the frame work could improve some to reduce weight.
Wood gave way to DEPRON
The frame was rebuilt with improvements also for the Duct-Vanes. In this version the DEPRON served as the skin, a good candidate, adding to the structural strength and easy to apply.
I decide to add a landing system, which doubles as a keel when retracted. This proved to me challenging first and a clever outcome is to come from this. The main landing strut will encompass all structural bearing loads, along with main bulkhead. The rear landing gear will eventually serve as rudders in water, and on land steering.
Surface controls
My next step is to finish my control surfaces, linking up all the surfaces to their appropriate servos. Because of the awkward position of each control surfaces and the combination of their use choice of mechanical vs. Electronic mixing was determined. I decide to go with mechanical as it was more affordable, also proved to be challenging. The canard system is to be linked to the elevons in the opposite direction to work properly, this is to assist in the flight maneuvering. Also connected to the elevons are the Duct-Vane’s control surfaces as an extension of the elevons. My only worry at this point is the surfaces may not be sufficient in size. This will be determine in the test flights.
Power train
Next the Duct-Vanes are fitted with the fan units. The construction method has room for improvement. Remember this need to be waterproof and with the paper construction a different material will need to be used, most likely a plastic or composite type material will be the choice in future development. As for the choice of motors and fan combination is restricted by my funds and this will be a real challenge to get the optimum power assembly for the Duct-vane. I hope the 55 mm fan units will be sufficient for this project.
