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The Bird Man

Artwork By     P2

 

D-III VeeBee

The D-III VeeBee is the third generation of the Ductling a Blended Wing Body (BWB) with the Duct Tail now dubbed the "Duct Vane" mainly because it is a directional duct with control surfaces.  In a "V Tail" configuration provides complete directional control under power achieving vector trusting and without thrust through the "Duct Vane" the control surfaces are still operational for a controlled glide.

A prototype of the Ductling D-II static model was built to play with the idea and see if it was feasible.  This provide a new form of construction with a foam plastic call DEPRON, commonly used for fast food for take out also foam trays are made from it, and the trays I collected over time provided me the base material from which I built the Ductling D-II. After building the model it looked good enough for me to actually install the components to make it fly, fans units, receivers and servos. I decide to take it out for a test spin.  I quickly discovered that the model was not properly fitted for the fan units. the "Duct Vanes" where not to specification for the fan units, thereby rendering the thrust ratio inadequate for the Ductling D-II.

So I decide to work out design details to simplify the building process. First was going to be the materials used.  The goal build lighter and stronger.  I began to search the web  for foam. Not yet familiar with the product DEPRON, my search was fruitless,  but stumbling on sites focusing in foam plane construction I quickly discover the foam associated with building model planes.  My first discovery was a site FoamFly.com where the product was Fan-fold.  Fan-fold is a lightweight sheets of Extruded PolyStyrene foam. Most of them are used for insulation under side paneling some have a laminated film that added strength to the sheet.  This looked like the product I needed for my project, but it is not available in Canada.  This added to my frustration in obtaining this material. Now the trick is to find a supplier of this foam.

I came across an other site Yann's Model Airplanes. This side shows how fun foam plane can be. simple and fast to build, any shape is possible. Here is where I found the magic word DEPRON, it did not register yet. It is funny how thing turn out.

I went to Toronto's annual Hobby show in search for new toys and discoveries. There the focus on indoor flight stuck with me. It appears that everyone is taking up or buying in the new thing with foam planes.  They are much more forgiving when hitting the ground. So maybe here in the show I will find this marvelous material. Only one of all the booths had this product, and it came in 3mm and 6mm. I made the mistake of not buying any or asking what the product was. A month and a half later I went to my favorite hobby store to purchase a heat gun. I asked if they had foam sheets. Well.... The reply was ... You must mean DEPRON  So... that's what it's called. At $8.50 for 15"x39" was not attractive for me.  I went home and search the NET.  Now armed with the KEY WORD I searched for DEPRON.  A sight of content was in my breath as I searched. I quickly found sources and dimensions favorable for my project.

I decide to go back to FoamFly and purchase a new product 1mm foam rolls  @ $1.00 a foot x 47" this was a start. My guess this is 1mm DEPRON, Be careful to ask Dan to pack the material with extra protection if it is traveling a long distance, because when I receive the package it was damage. Shipping through the post office I did not consider their recklessness by pilling other items onto mine and crushing it. Dan from FoamFly quickly responded to my distress and provided me with a replacement.  With this thickness of 1mm would require a layering technique for larger project.

 

Project Details

 

Building the fuselage

After working out the CAD drawings the parts where cut and built for assembly. The basic parts are laid out for fit. Two boards where placed underneath each side of the fan unit allowing the fan sit properly in the bulkhead, ready for assembly of frame work. Construction of the frame work was done with 5/8"x3/32" and 3/16"x1/4" strapping. In order to build light the skeleton is kept simple. Using plastic pop bottle material for the intake manifold, helped with improvising the proper shape needed and keeping the weight down. Looking at the fan shroud bulkhead is a build up of several layers like plywood to strengthen the joining wings.  A view of the boards underneath is shown more clearly to allow the shroud to fit.

The Duct-Tail

Making the mold for the Duct-Tail, I used the general shape caved out of foam and covered it with balsa to protect it from the fiber glass resin. The frame work was completed with capping the frames using 1/2 x 1/16 " ribbon strips.  This would reinforce the frame and provide a surface for the covering.  The Duct-Tail is fitted for assessing mounting detail at the tail end exhaust, and a simple solution is determined in fixing the mount for the Duct-Tail.  A clever seat was devised to catch the shroud and mounting it in position. This will also provide as a guide for the rudder assembly. The configuration is taking shape. The wiring is fitted through the shroud crisscrossing inside and aligned with the fins to minimize turbulence.  A rib is added top and bottom of the shroud to strengthen it and give shape for the outer skin of the Duct-Tail.  The rib provides a locking mechanism for the fan shroud to hold it in place at the bulkhead.  The rudder is assembled and fitted for detail assessment on control access.  A wire frame is added to help maintain the shape of the exhaust in the tail.  A rear view of the Duct-Tail shows the details of the clever set-up.   A servo is mounted on the bottom for the rudder control. It was determine that a servo would be places underneath the inlet spoon and on either side of the rib the control rods are attached to the rudder by means of a push/pull horn system.  With receiver, battery and servos in placed. 18 oz.  Painted and covered, ready to go.

A preview of the next revolution, a twin fan V configuration.


 

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