Popular Science Monthly 



"^91 



The piston-heads may be cast in the 

 eccentric ring. Sim()iy lay the ring 

 on a piece of paper on a flat surface and 

 pour it full of hahhiu. Two of these 

 are required. -After casting, tlie center 

 is carefuli\' 

 located with a 

 pair of di\id- 

 ers, after which 

 a 5 i6-in. hole 

 is drilled 

 through it. To 

 cut the groo\e 

 in the pistoii- 

 heads the 

 arrangement 

 shown on this 

 page is used. 

 .\ block of 

 wood has a 

 5 i6-in. hole 

 iiored through 

 it. A piece of 

 5 i6 in. iron is 

 threaded on 

 one end and a 

 piston held in 

 place on it by 

 meansof locked 

 nuts. The other 

 end of the iron 

 is run through 

 the block anti 

 bent into the 

 form of a crank. 



was the eccentric mold, except that no 

 ring is used and the hole for the shaft 

 is in the center. .\ hole must be pro- 

 \ided for pouring. When pouring, be 

 certain to have the shaft set square with 



, t h e m o 1 d . 



D ^ ''"1 ^Ttr ^[luare up by 



the method 

 suggested in 

 the drawing. 



The tl\- wheel 

 is made of lead 

 or babbitt. In 

 this case the 

 mold is about 

 3'4 in. deep and 

 3 ins. in diame- 

 ter. The shaft 

 should be in 

 the mold when 

 the casting is 

 made. 



The bearing 

 support is 

 easily made of 

 cither iron or 

 brass. Bend to 

 shape first and 

 then lay off and 

 drill the holes 

 for the bear- 

 ings. These 

 are short pieces 

 of pipe used 

 for the steam- 

 Drive a nail into the block for the K^-in. chest, ports, etc. Place the shaft 

 chisel and the groove is cut by turning through the bearings, and place the 



fiCARI^KJ 5U«>CWT - 



CYLINOCR SUPPORT 



5MeCT METAL 



TWO R£<^UIReD 



Plate 3. Diagrams showing dimensions of the vari- 

 ous parts of the opposed cylinder steam engine 



the piston and holding the chisel against 

 it. The grooves are cut >4 in. deep. 



The piston-rods are worked out from 

 cold rolled steel or brass. Only the one 

 needs the ^s-'ui. notch cut into it as that 

 is for the connecting rod to fit into. 

 The two inner ends of the piston-rods 

 are lapped together and bolted with two 

 } s in. by Jo 'i- stove bolts. A Jg'*'^- 

 hole must also be drilled in the center of 

 the space allowed for fastening the con- 

 necting rod. The pistons are held on 

 the ends of the connecting rods 1)\- 

 means of locked nuts. Note Plate 2. 



The connecting rod is .sliown in Plates 

 2 and 3. I'se 'g in. by i^o in. material, 

 either brass or iron. The curves may be 

 worked out with a file. 



The crank wheel is },■> in. thick by 2 

 ins. in diameter. The mold is made as 



)earmgs in place in the support, when 

 the\- may be soldered in position. 



The shaft is shown in Plate 3. It is 

 best made from cold rolled steel although 

 brass will do. 



Ha\ing brought all of the details to 

 this jjoint the most interesting part is 

 now to be done. 



In a.sscmbling, fasten the connecting 

 rod in position on the piston-rod. I'se 

 a Js-in. rivet for this, but do not make it 

 too tight. Pack the pistons with cotton 

 waste, asbestos packing or soft yarn. 

 Assemble them in position in the 

 cylinders, bolt them together and see 

 that they work smoothly. Next place 

 the shaft in position in the bearings with 

 the eccentric and eccentric ring in place. 

 Fasten the eccentric to the shaft by 

 drilling a small iiole down through both 



