112 



PATTERN MAKING 



will be seen, has no Sltpporl except that afforded by tin- extra length 

 of the core at tin; opposite end. Tho pattern for this chuck is 

 shown in Fig. 199, and the core print must have a length at least 



twice as great as the depth 

 of the hole in the chuck. The 

 core box is shown in Fig. 200. 

 When pipes or cylinders 

 are of moderate size with deep 

 flanges for bolting together 

 (Fig. 201), the flanges for the 

 pattern are turned out of a 

 separate disc as shown in 

 Fig. 202, and firmly glued and 

 nailed on over the core prints 

 and against the ends of the 

 main body of the pattern; 

 the core print being made of 

 Fig. 197. sufficient length to receive 



the flange. A recess is sometimes turned in the inside end 

 of the core print to receive the inner edge of the flange as 

 shown in Fig. 203, and into which it is fitted, thus adding greatly 

 to the strength of the joint. 



Fig. 198. 



Fig. 199. 



The flanges should be made by gluing up three pieces and 

 crossing the grain of the pieces so that the grain of each will run 

 at right angles to that of the other. In gluing pieces together for 

 thin discs, three pieces should always be used. Two thin pieces 

 glued together will always warp. 



