A Boomerang Flyer 



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A LITTLE gyroscopic flyer which can 

 be adjusted so it will return like a 

 boomerang can be made by any 

 intelligent boy. Excepting the shaft, every 

 part can be made with such simple tools as 

 a jack-knife, a pair of pliers and a hammer. 

 The only outside work required is the boring 

 of two small holes in the shaft. This a 

 watchmaker or jeweler will do. 



The flyer may be made any size t but as 

 the power which is available must be con- 

 sidered, the following dimensions are sug- 

 gested: The disk A should be 10 in. in 

 diameter made of a thin tar board, for this 

 material is absolutely flat and does not 

 warp or twist out of shape. Aluminum is 

 also serviceable. Unlike the common glid- 

 ers, lightness is not the first consideration. 

 On the other hand, weight is of con- 

 siderable importance, as the ability of the 

 device to soar depends on the momentum of 

 the disk itself. In using aluminum, No. 28 

 gage is the best thickness. 



Centrally in the disk is a hole to receive a 

 3/16-in. steel rod B, 4 in. long. Exactly in 

 the center the rod is bent at right angles so 

 that each part, B and C, is 2 in. long. The 

 part C is bent laterally, at a point midway, 

 as shown at D, so that it will lie flat on the 

 disk, and an end E is turned up so it will 

 serve as a crank handle. The object of 

 this arrangement is to provide a means 

 whereby the disk can be rigidly fixed to the 

 stem so the plane of its surface will be 

 maintained perpendicular to the stem B. 



After the stem B is placed in the central 



hole of the disk, wire staples F may be 

 used to fasten it firmly, as shown. Through 

 the stem portion B two small holes G are 

 drilled Y2 in. apart, to receive a bent pin 

 or wire H, which provides a means for 

 attaching a rubber band. 



The body of the flyer is made of a strip of 

 pine /, 9J/2 m - long. I in. wide and % in. 

 thick. The interior portion of this strip is 

 cut away to form an upper and a lower bar. 

 The forward end is tapered off to form an 

 A-shaped edge, while the rear end has a 

 blade /, made of thin aluminum 2 in. long 

 by 1 Y2 in. wide, to serve as a rudder. The 

 metal should be thick enough to remain set 

 after bending in either direction. 



A hole is bored vertically through the 

 upper and lower bars of the frame to 

 receive the stem B. A short tube K, y% in. 

 long, is placed on the stem between the 

 disk A and the upper edge of the strip /, 

 and a thin washer L is placed between the 

 pin H and the lower side of the upper bar. 

 By this means the stem B is held rotatably 

 fixed to the frame. 



The rubber band M which serves as the 

 motive power, should be 4 in. long by x /i in. 

 wide, a size easily obtained. The rear end 

 of this elastic is secured to the side of the 

 strip / by means of a wire staple N. 



If the elastic band is wound up and the 

 flyer thrown into space it will sail along 

 with remarkable evenness of flight, due to 

 the gyroscopic action of the rotating disk. 

 The propelling device consists of a pair of 

 triangular-shaped blades, 0, secured to the 

 opposite ends of a light wire rod P. This 

 rod has at each end a projecting right- 

 angled bend Q, to which the blades are 

 attached. 



Each blade has at its rear margin a 

 downwardly-projecting and rearwardly- 

 extending finger R, which passes through a 

 slit in the disk A . These fingers have two 

 functions; first, to hold the propelling 

 mechanism in place, and second, to rock 

 the wire rod P back ^nd forth. The 



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