114 



PATTERN MAKING 



tion find doing away with the otherwise temporary center block. 



The method of constructing the core box for this or similar 

 patterns, is shown at 6, Fig. 204. 



Tees, elbows, and other bends and connections, when large, are 

 built up in a similar way, thus making a lighter, and also more 

 durable pattern. 



Fig. 205. 



Fig. 206. 



For large cylinders, a much lighter and simpler method of 

 constructing the pattern is shown in Fig. 206. For each half of 

 the pattern the two end discs, and the middle semicircular disc are 

 connected together by a strong center bar, which is fitted, glued 



Fig. 208. 



Fig. 207. 



and screwed into each, serving not only to strengthen the pattern, 

 but also to hold the connecting dowel pins. When the two hah'es 

 of the pattern are clamped together (with staples) it serves also as 

 a secure means of centering in the lathe. 



The staves forming the body of the cylinder are fitted and 

 glued to each other and screwed, or nailed to the discs After the 



