108 



PATTERN MAKING 



as illustrated in Fig. 188. The preparation of the wood for this 

 pattern is similar to that described for the pattern of the brass 

 bearing, Fig. 150; the two halves having the necessary dowel pins 

 inserted, and glued together at the extreme ends only. 



When there is not time for the glue to dry, all such parted 

 work may be held together while being turned, by having staples 

 driven into the ends as shown in Fig. 188. Indeed, for all large 



and heavy work this method is to 

 be preferred; two, and even four, 

 staples being used in each end as 

 the size of the work may demand. 

 When the turning is completed. 



[TB5JI . |fl^ 1 {i is onl y necessary to cut a V- 

 =^ ^= ^1 shaped opening into the two 



halves of e, into which the part/" 

 is fitted and glued. When the 

 glue has set and is sufficiently 

 dry, the joint may be further 



Fig. 185. 



strengthened by nailing, or by inserting and screwing a thin metal 

 connecting plate flush with the parting side of each half of the 

 pattern. This, however, will be necessary only when patterns are 

 1,-irge and heavy, or when unusual strength is required. 



The core box for this pattern, as will be seen in Fig. 189, is the 

 usual half box and is made 

 by working out the box in 

 one piece, long enough to 

 make the two parts a and It. 

 The two parts are united by 

 cutting a V-shaped opening 

 In the part a and fitting b 

 into it in the s;ime way as 

 describedv for the pattern. 



The whole is then glued and 



Fie 186. 

 screwed to the board <?, and 



the two triangular blocks d and d are glued in the angles to add 

 strength to the completed box. In case the pattern is for a very 

 small pipe, 1 inches or under, the part 1> may be abutted against 

 the side of , as shown by the dotted line, and the side of a 



