70 



PATTERN MAKING 



ings will be shown. These dimensions will, in .ill cases, be arbi- 

 trary. ;ind can be changed at will, if for any reason alteration is 

 necessary. The successive steps in the construction of the pattern 

 are given in detail so that the student may fully understand tin- 

 principles involved. 



The first article for consideration is the IH-HKX ////*/////// flanged 

 at one end, illustrated in Fig. 139. This bushing is to be finished all 

 over, and as the casting is small, iV inch will be sufficient for out- 



-w 



CO 



Fig. 140. 



side finish and the same for turning out the inside. On examining 

 it with regard to moulding, we find that if moulded on end with 

 the flange up and on the parting line of the flask it can be readily 

 removed from the mould. 



The draft in this case should be inch in 12 inches or a little 

 less; and each core print, because the pattern is very short, need 

 not be more than f inch long. Having the finished sixes given 

 (Fig. 139), and having decided on the amount of draft and finish, 

 the pattern will be as represented by Fig. 140, and in the case of 



