Dragonfly Quadcopter Drone

Well, I recently sold the Heavy Lift Quadcopter from a previous build log and was left feeling a little Heavy Lift Quadcopter-less. I have some spare motors and a bunch of wood lying around the shop and figured I’d put it to some use designing something for pure fun. Wood is a natural vibration dampener and so I’ve always wanted to try a 100% wooden build to see how well it does in isolating the vibes. My work tabletop is a nice piece of hardwood ply, so I figured I’d use my technical drawing skills to lay out the design right on the table. The specs so far: symmetrical design with the motors laid out on a 22″x22″ square giving a diagonal motor to motor distance of 31.11″. Arms are 1/2″ x 1/2″ basswood. They may be a little thin, but wood is easy to replace and aluminum may be substituted in the future. Rear arms are 18 7/8″ and front arms are 13 7/8″. The wood is finished in a navy blue water based acrylic – fast drying, low odor, and easy to work with. Here are a few shots of how this monster is beginning to shape up:

The frame has been designed for mounting Tarot 12mm carbon fiber rails. The plan is to hang the camera gimbal out front, no further forward than the #1 and #2 motor shafts, but far out enough to have no props in the image with a wide angle lens. I also wanted the frame to extend aft enough to allow balancing with a nice fat 4S LiPo battery. She’ll swing 14″-15″ props. After completing the drawing of the arms on my work tabletop (I know, some will consider this low tech and even barbaric), I transferred the drawing by hand to 1/8″ plywood so that I can cut out the frame. Before cutting I also wanted to plan and layout all the holes that will need to be drilled to secure the top/bottom of the frame and the arms together. It’s going to be a little funky looking for sure. I like it so far though, and this is what has transpired for now:

The next step is to cut out the top and bottom frame plates. Before doing so I was sure to accurately diagram all the dimensions so that the drawing can later be transferred to CAD should I wish to CNC a G10 fiberglass or carbon fiber version of this frame. Before cutting the frame plates, I thought it would be best to drill all the necessary holes. All holes in the frame are 3 mm diameter except for those used for the Tarot camera rail mounts, those 8 holes were 2.5 mm. The holes will be used to attach the top and bottom plates with 1/2″ spacers, and to attach the arms to the frame. I also drilled holes for an OpenPilot CC3D control board, however I will be placing a NAZA-M V2 in this build to start out with. I chose to cut both plates at the same time. To do so I clamped the plywood together and used my trusty Bosch jig saw to free the frame’s shape from the plywood. A few 3/4″ holes were added to allow for strapping things down and/or running wires. Once the frame was cut, I just sanded it down and applied a layer of navy blue acrylic paint. Here are the photos:

This was the moment of truth for me when it came to this build. If I bolt everything together, will this thing look like a flying machine? Well, I was sure it would resemble a dragonfly, but my wife kindly pointed out that it looks more like an electric guitar. I think she’s right. Now for some build details, which is what you’re probably reading this for.

The top and bottom frame plates were bolted together using a combination of M3x23 screws with 1/2″ nylon spacers and 4-40×3/8″ screws with 1/2″ aluminum spacers. I don’t discriminate between metric and standard, I like them both. The motors I’m using are Exceed RC Rocket 3015-840kv beasts which were left over after I upgraded my last heavy build to Tiger motors. They are mounted with M3 screws and six 000 sized rubber plumbing washers(3 per screw).

Bolted to the top deck is the Tarot T810 PTZ Mount Kit TL96014, a nice beefy setup. It consists of 12mm X 440mm carbon fiber rods and aluminum/silicone shock absorber mounts. The tray up front is a pretty heavy duty carbon fiber battery tray, also from Tarot – part #TL96018. Lastly, I attached a set of the Lemon landing gear I designed. They will need to be replaced with some taller gear once I assemble a new brushless gimbal for my Sony NEX5R. Next comes the wiring and installation of the DJI Naza-M V2.

Details will be posted shortly, but for now – here are the photos:

Arggh! She crashed on her maiden flight. Will post my findings soon, but I believe it was either an ESC or Motor failure. Will be a quick fix though as the only damage was 2 broken arms. Wooden quadcopters are easy to repair!