446 



Popular Science Monthly 



ment. The first cost for installing the 

 machinery is the greatest expense. The 

 up-keep amounts to very little, especially if 

 the owner is fortunate enough to secure the 

 services of an intelligent man-of-all-work, 

 one who is handy with tools and can make 

 ordinary repairs when necessary. On this 

 particular farm the handy-man was the 

 inventor of the tank heater for the engine- 

 house and watering trough. He also 

 fitted up the family surrey with electric 

 lights, fitting the tiny bulbs into the lamp- 

 wick sockets, and connecting them with 

 dry cells placed under the front seat. A 

 home-made switch turns on both lights at 

 once. 



Foot-Power Jig-Saw Made from a 

 Sewing Machine 



AN old sewing machine that had out- 

 jLjL lived its usefulness in that capacity 

 and was to be discarded made the ground- 

 work for the jig-saw as shown in the illus- 

 tration. The shuttle, the mechanism 

 driving the needle-holder and the step v/ere 

 removed. Only the hand-wheel together 

 with its shaft and cam-disk at the end were 

 used. 



The frame of the jig-saw consists of two 

 arms 21 in. long, ^ in. wide and 3^ in. thick. 

 Each piece is drilled through the width, 

 making three holes, one 3/16 in. in diameter 

 }/2 in. from the rear end, one 15 in. from the 

 same end, and one 3<C in. hole 3^ in. from the 

 opposite end or front end of the frame. A 

 i/i6-in. hole is made in the side of the 

 upper piece 4}/^ in. back from the front end. 

 The two pieces are held together at the rear 

 end and 6 in. from the front end with 

 bolts having long threads on each end and a 



■^BA5E PLATE 



The frame of the jig-saw for attaching to the 

 sewing-machine table and head for small jobs 



nut on both sides of the stick. The rear 

 end bolt is made up of two pieces, each 

 2}4: in. long and 3/16 in. in diameter with 

 threads on both ends, i}^ in. in length on 

 one end and 34 in. on the other. The 

 shorter threaded end is turned into a hole 

 tapped into the side of a round piece of 



iron that is ^ in. long and ^ in. in diam- 

 eter. The piece is also drilled centrally 

 with its length for a 34-in. bolt. This bolt 

 runs through a standard io3^ in. long, ^ 

 in. wide and 3/16 in. thick that is fastened 



The frame on the sewing machine where it is 

 driven by a crank attached to the head shaft 



to the base plate of metal running beneath 

 the sewing-machine top. This latter plate 

 is 21 in. long, i3^ in. wide and 34 in. thick. 

 This is fastened to the top with a thumb- 

 screw turned into a tapped hole in the 

 metal sewing-machine base. 



In the outer ends of the saw-arms are 

 placed screws which are centrally drilled 

 for the saw-blade end and a set screw 

 affixed to clamp the saw in place. The 

 sawing table is made up like a three-legged 

 stool, the top being a round disk 6 in. in 

 diameter and 34 in- thick. To prevent the 

 saw blade from lifting the board up at each 

 stroke a guide is used above it. The guide 

 consists of a 3/16-in. rod bent L-shaped, one 

 end being flattened and the other having a 

 long thread cut in it. A bar fastened to the 

 lower part of the square frame on the 

 sewing-machine head makes a support for 

 this guide. 



A short pitman is used on the cam-disk 

 to drive the frame. The shaft and cam- 

 disk are, of course, driven by the usual 

 treadle, wheel and belt drive that was 

 originally used on the sewing machine. 



While this arrangement does not give 

 any great swing in the opening under the 

 sewing-machine head it can be used on a 

 great many pieces for building up small 

 work. — E. M. Davis. 



