Beware of online tutorials that make an "ornithopter" from household materials.

Welcome to the exciting world of flapping-wing flight! Seeing them fly is amazing, but it is not easy to build an ornithopter. You can improve your chances of success if you start off with a proven design before beginning your own experiments. The best way to get started is with an introductory model kit. The special parts in the kit, such as the pre-bent crank wire and interlocking wood parts, will save you a lot of headaches.You will also save money because the kit costs less than buying all of the materials separately.

Building the Gryphon

The Gryphon is a new model kit I designed to help students and hobbyists get started with flapping-wing flight. It is available from BirdKit.com. Unlike earlier kits, the Gryphon features interlocking wood parts that make it easier to build. It is made in the USA from natural materials, and it can climb high in the air. The Gryphon flying bird model kit can be assembled entirely with non-toxic white glue.

The first step in building the Gryhpon is to assemble the wooden strut that holds the crank wire. The parts have been laser-cut from lightweight birch plywood only 1/32" thick. They fit together with special notches to aid in correct alignment. The crank bearing is held securely by the wood parts, without any need for messy layers of tissue to hold it in place.

The tail of this ornithopter is set at a fixed angle. Earlier kits had adjustable tails, and I observed that students were failing to adjust them correctly. The Gryphon tail is not adjustable. If you interlock the parts correctly, the tail will always have the correct angle for a stable flight.

The wing lever wires, like the crank, are secured in place by interlocking plywood parts. The wing lever wires slide into sockets on the ornithopter body. The wing material is a colorful, high-grade tissue paper. It's easier to attach than a plastic film would be.

The Gryphon kit comes with a high-performance elastic. It's the same stuff they use in model airplane competitions. You cannot use office rubber bands in these models. It's important to lubricate the rubber band, and BirdKit.com sells a castor oil lubricant that is safe and non-toxic.

The Gryphon should fly alright on the first attempt. If it nose-dives, you probably didn't put the tail on correctly! (Use water to soften the glue so you can realign the parts.) Just by a few simple adjustments, which are explained in the kit instructions, you should end up with a great-flying bird. Next, you can do some simple experiments with your Gryphon to start learning more about how these models operate.

Gryphon Experiments

One Wing Flapping: Slide the rear connecting rod all the way back against the crank bearing so the left wing doesn't move when the crank rotates. With only one wing flapping, your ornithopter should turn sharply to the left. Now add weight to the right wingtip until the ornithopter turns right! Is it really flapping just one wing?

Mess Up the Flapping Mechanism: Get some 1/32" music wire at a local hobby shop. Make a new crank with a smaller radius than the original. How does this affect the flapping rate, and the flight of your ornithopter? You can also change the length of the connecting rods by adding new holes with a 1/32" drill bit. Make small changes and observe the results.

Bigger Wings: Tear the wings off your model. Moisten the tissue along the top of the fuselage, and after a few minutes scrape it off with your fingernail. Make new wings with a wingspan of 24 inches. Larger wings will cause the rubber band to unwind more slowly. This could give you longer flights, but it also means your ornithopter won't be getting as much power. Gradually decrease the wingspan, and make a series of timed flights to find out the optimal wingspan.