Here's just a shape I like.... will it fly?

OBJECTIVE: A bird like shape with a "high tech" spin.

COMMENTS: Here is another FOAMIE prototype I'm working on. It is a shape I have been thinking about for some time now. I have admired the general shape of Hawks, Petrels, Falcons etc. and I thought it might be fun to emulate that shape. The more complete it gets the more I think it looks like a Frigate, what do you think? BUT... will it fly and if so, what will the performance and flight characteristics be like? I am after more of a floater/thermal ship and the airfoil is pretty thick so I don't see it as being a speed machine. It should be interesting to see it fly though!

This is completely from scratch (the design... I modified some wing cores I already had) and so it may be slow going as I figure out the best "backyard" engineering as I can...

Click on the thumbnails to ENLARGE.

After modifying the wing panels for the different root angels the first step was to glue them together. I made the main spar hollow 2 piece so I could make them "plug in" types for any future fuselages. After determining the spar length I wrapped them in kevlar thread to resist side splitting with minimal weight penalty.
Here is the incidence pin layout. I went overboard and used the same size as the main spar for simplicity. Had to make sure both rods were parallel! I also added a flat 3.8" CF "spar" 1.25" behind the leading edge and extended it to the tip for rigidity.
Here is the finished spar system. Lightweight and fairly strong. This will be a light weight ship so I kept things minimal. After the epoxy cured I filled the spar grooves. After I've decided where the servos will go I cut out the parameter with a sharp x-acto.
I use my dremel and the bit shown to make nice cut-outs for my servo bays. There's a nice tight flush fit. This setup with internal blind nuts makes for EZ and secure attachment of the winglets.
I just layed out a nice aero tear drop fuse' shape. I'm without hot wire at present, so it was the ol' hack saw blade trick... I inserted and glued in some CF tubes in the fuse to plug the wings into. I layed out the radio eqt. and servo to mark out the area in the nose to cut out.
After I determine what I want cut, I do the top cut first. Next I make one cut across the bottom. This allows the "plug" to be popped out. Here is the plug popped out. The area for the battery and Tx will be routed out to make a perfect snug fit.
I used the dremel to route out spots for the battery, Rx and elevator servo. Here's how to "pot" a servo: 1) Wrap the servo in cellophane. 2) Pour epoxy into the servo cavity and jam the wrapped servo in place.
After the epoxy sets, cut away the excess cellophane and epoxy. There you are... a servo that will stay put, yet can be removed when needed! I'm getting ready to make a hinge plate for the tail. I'm using a CF tube to be wrapped in fiber lass. Here is the hinge plate installed onto the back end of the fuse'.
I opted for a bird like hinged flat tail for elevator only, here is the first layer. I may try a V tail later... Here I am laminating CF and glass between two layers of balsa in a unidirectional arrangement for stiffness. Here is the finished tail... its BIG and I probably will only have to make it move a LITTLE for elevator control!
Backing up a bit, I made a cavity in the fuse for the servo wire plugs and routed the servo wires. To install the servo wires in the wing, just cut a slot and imbed the wire, tape over it when you are done. Setting up to cut the ailerons and flaps to length.
To trim a bevel I clamp two metal straight edges together, one lower than the other and it makes a perfect cut! I then tape over the servos (I use this heavy duty bi-directional strapping tape, works GREAT). For the leading and trailing edges I use the bi-dir'l tape, for the rest I use 1/2" or 3/4" strapping tape,
Now for the fun part... adding some color! For this proto, I will use packing tape. Here is the completed covering on the top. Now I mount the ailerons and flaps using hinge tape.
Next I mount the control rods and horns. Ready for the maiden flight... I may change the tail so I didn't cover the fuse & tail Yet. Top view... wonder how it's gonna fly!??

Flight Report 11/12/03:

OK, in short the big bird tail did not work, it had WAY too much pitch authority, so I made a quickie conventional coroplast tail.

Top view - I didn't even bother to taper the trailing edge for the next maiden flight. The tail was slotted in several places and strapping tape used to hold it on through the slots. EZ and secure. Here we go again... test flight when weather permits!

Test Flight 11/16/03

Well the new tail did OK but is still SUPER sensitive to pitch... but manageable. Man does this thing FLOAT?! Every time I gave it some up to flare the landing it would just pop up and keep going! This should be a nice slow stable platform to anchor my wireless video stuff to! Probably the one thing I need to work on is yaw control. I think the winglets are too close to the yaw axis and do very little. A large V tail will probably be needed to overcome the yaw issues of this lumbering wing! Now that I have the CG pegged I may just try the flying wing configuration and add a vertical fin... the experiment continues!

Hummmmm.... Well, I tried a V tail and that worked a bit better, but pitch is still a problem, so after many flights with a V tail I went with a single rear fin/rudder set-up. Then i switched to elevon control/flying wing configuration. I use only the inner "flaps" for pitch control and couple the ailerons and flaps for turning. I mix in a little rudder with the ailerons and it turns beautifully... I also have it set up for crow mixing which works well much to my amazement!

I've added a new V tail and eliminated the bird like horizontal tail. I had to keep chopping the "ruddervators" smaller and smaller as pitch was still too sensitive. Ah... the key: A simple vertical fin with rudder. Ummmm.... nice: Crow mixing!

Oh, I do eventually plan to motorize this thing.When I do, it will be a rather spunky brushless set-up!

Below are some flight photos... what a mellow flying plane!