WRIGHT BROTHERS Aeroplane Company

o help you gather the materials for your Wright glider and Flyer replicas, here are the sources we have found. If you find different or better sources, let us know and we'll post them.

Engine Castings
That's right! ENGINE CASTINGS! For the first time ever, you can purchase a complete set of castings for the 1903 Wright Flyer horizontal four-cylinder engine. You can use these castings either to make a dummy engine for your '03 Flyer, or you can do the machine work and make a working engine. About a year ago, some very good folks at Sand Castings of Maine agreed to make the castings for us for our Centennial Flyer -- the 1903 Flyer replica that we are building with the help of children. In the process, they decided to make precision matchplates so they could make additional sets of castings on demand. For the last year, they have been perfecting the tooling. They shipped us our Centennial Flyer castings and, according to our machinists, they are everything we hoped they'd be -- and more.

Here's what you get -- engine block, journals, cylinders, combustion chambers, valve guides, and flywheel.

Those parts that get the hottest are made from silica-bronze, an alloy that is as strong as some steels but is much more stable under extreme heat.

A close-up of a silica-bronze cylinder, combustion chamber, and valve guide.

The engine parts are sand-cast. The tooling for the sand molds was machined from epoxy resin for durability, stability, and precision.

The casting set consists of an engine block, bearing journals, cylinders, combustion chambers, valve guides, and flywheel. It doesn't include the pistons, connecting rods, or valves -- all of these parts can be purchased off the shelf from any automotive supplier. The engine block and journals are made from an aluminum alloy, of course. Those of you who know your aviation history also know that the Wright engine was the first aluminum block engine. The cylinders, combustion chambers, and valve guides are made from silica-bronze. The originals were cast from iron and steel, but the Sand Castings of Maine folks convinced used that bronze was a better choice. This engine is a thermal nightmare -- it overheats in a heartbeat; parts glow dull red. Bronze is more stable and dissipates the heat more quickly than iron or steel. The silica-bronze alloy used is stronger than many steels -- the bronze cylinders will wear as well as or better than the originals. If you're making a working engine and want harder cylinders, you can always have the bronze chromed. If you want to remain true to history, Sand Castings of Maine will cast the parts from the original materials the Wright brothers used. But we figure that once our engine has been run a few times and the bronze gets good and greasy, you won't be able to tell it from iron.

The flywheel is aluminum rather than cast iron to save weight. With a balanced crankshaft, we shouldn't need all that mass to keep the engine turning at a reasonably consistent speed. However, like the cylinders and combustion chambers, the flywheel can be cast out of the original materials if you so desire.

The cost of the casting set is $7500 -- a bargain when you consider that Sand Castings of Maine estimates they have over $35,000 in the tooling needed to make the castings. We would have had to make the same investment if we hadn't stumbled across some good folks who own a foundry and are as nuts about the Wright brothers as we are. Contact Frank Mikkelson at:

Sand Castings of Maine
60 Dogwood Drive
Shapligh, ME  04076
mailto:[email protected]

Working Engines
Using Sand Castings of Maine's casting, master machinist Terry Hesler has begun to build three working Wright engines for us -- one for each of our Flyers and a third that can be run on a demonstration stand. Terry has told us that he would be willing to build more engine while he is set up to build ours. The time-consuming part of machining these engines is the set-up, so he could build ten engines more economically than he could build one.

Terry will build these engines either carbureted or non-carbureted,  The non-carbureted engines will be precise replicas, just as they are shown in the Smithsonian drawings. These engines run, but you should know they were never meant to be run for long periods of time. They overheat easily, and when they do the wear on them can be substantial. Furthermore, they are hit-or-miss engines with just two speeds -- on and off. Consequently, when replica engines such as these are demonstrated, the demonstrators usually run them on propane to keep them cool and prevent wear. If you'd rather run them on gasoline, Terry will also make a carbureted version with a throttle-body carburetor, as well as some improvements in the oiling and cooling system. This will keep the temperature from building and the parts from wearing during demonstrations.

The cost of these engines will depend on just how many Terry can make at once. The cost of the castings is $7500, with several hundred more for materials and a magneto. The cost of the machining will be spread over the entire run. We're expecting each engine to cost between $25,000 and $35,000, depending on how many engines Terry makes. If you'd like to have Terry build an engine for you, ping us at mailto:[email protected].

Spruce
You need aircraft-grade spruce for Wright gliders and Flyers This wood must be straight-grained, knot free, and should have a minimum of 14 annual rings per inch. (The tighter the spacing of the annual rings, the stronger and more stable the wood.) The best source we�ve found for this material is:

Ash
You also need 4/4 (four quarter) straight, clear ash for the bentwood parts of the Wright aircraft (about 80 board feet for a 1902 glider). Additionally, you should use this material for parts where extra strength is needed, such as the skid tie bars and the bottom elevator control arms. You can buy ash from almost any dealer in hardwood lumber, but there�s a hitch. When bending wood, air-dried lumber is superior to kiln-dried, and most dealers stock kiln-dried only.

Boxwood
The Wright brothers used boxwood roller skate wheels to serve as the pulleys in their early aircraft. These are no longer available, but you can still buy boxwood from dealers in exotic woods and turn your own. We purchased our boxwood from:

Waxed Twine
The Wrights lashed the frame of the aircraft together with a material they called "lacing cord" - waxed twine. Lacing cord is still available today, but no one will know what you�re talking about. Order "12-cord waxed linen twine" or, if that gets you a blank look, "#12/3-ply right waxed linen holdfast." Buy 3 600-yard rolls of the "natural" color from an industrial supplier such as:

McMaster-Carr Supply Corp.
P.O. Box 440
New Brunswick, NJ 08903-0440
(732) 329-3200

Mild Steel
To make the wire hardware, you need about 1/4"-diameter steel rod and 1/8"-diameter steel rod (20 linear feet and 30 linear feet respectively for the 1902 glider). For the strap hardware, purchase 24-gauge sheet steel and 16-gauge sheet steel (2 square feet and four square feet respectively for the 1902 glider). Buy mild, low-carbon steel such as AISI 1018 or its equivalent. Specify hot-rolled rod and sheet stock - cold-rolled stock is too brittle.

Aircraft Cable
Small-diameter aircraft cable is available through any hardware store. After swagging, we wrap the swage with 1/2"-wide copper foil (available from anyone who sells stained glass window supplies) and coat the copper with solder. This disguises the swages and gives the cable fittings much the same look as the wire joints on original Wright aircraft. an For the 1902 glider, purchase two 500-foot reels of 7x7 1/16" stranded cable and about 300 1/16" swages. You�ll also need a swagging tool - we recommend the Nicopress because it crimps the swages and cuts the cable.

Wing Covering
You need a very tightly-woven fabric to cover the wings. The current wisdom among aviation historians is that the Wright brothers did not dope their wings.* They simply put up with the loss in lift caused by the air bleeding through the fabric and kept this to a minimum by using a tightly-woven cloth. Their choice was a 100% cotton muslin called Pride of the West commonly used for women�s underwear. It had warp of 107 threads per inch and a weft of 102 from a total thread count of 209.

If you look around, you can find some tightly woven cotton cloth, but you must be careful. Spring of South Carolina manufactures a 100% cotton with a thread count of 197 sometimes called Made-Sew-Fine, but more often simply referred to as  Springs 200 Muslin. When we decided to recover our 1902 Wright glider after two flying seasons, we purchased this material and we're extremely sorry we did. When you stretch the muslin, there is more "give" in the warp than the weft. Additionally, when the cloth gets wet, the weft shrinks more than the warp. These two characteristics combined to pull the wings of our glider into parallelograms! We're now faced with the chore of recovering them again.

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