554 PEI.I. SYSTEM TRCIISICAL .'OURSAL 



nicth<Kl, would 111' li(|iii(latal in oiu- yi'ar h\ the decreased niaiui- 

 fartiirinj; tosl. 



W'luTf a liii;li (k'jiivc of arcurar\- is required on a piece of apparatus, 

 the overall effect on the tool equipment is to require a greater number 

 of individual tools, as well as to require tools of a higher grade of 

 wi>rknianship. For instance, it may be necessary in the case of a 

 puncii press part to hold certain dimensions of the blank to extremely 

 close limits, and this quite often requires an additional operation of 

 shaving the blank to size. This adds an additional tool to the equip 

 ment, as well as requiring a tool of greater accuracy. 



You will appreciate that the matter of interchangeabilily is one of 

 great importance — first, because the parts must go together in the 

 assembly departments without any further fitting — and second, 

 the parts and pieces of apparatus shipped over the entire country 

 for repairs and maintenance must be exact duplicates of the old. 



It costs more to make interchangeable parts than to make inaccu- 

 rate ones that are not always interchangeable, and the Planning 

 Kngineer can coniml liie lool and manufacturing costs very largeK' 

 by his judgment in liie selection of limits. 



HolRI.V OlTPLT 



rile I'l.innini; Engineer, in anahzing the wt)rk on a ,i;i\en \raT\ for 

 the ()i)erati(in^, machines and tools to be provided, from his experience 

 and training in the particular kind of work he is handling, is able 

 to establish .in expected hourly production for each operation he 

 handles. He is, of course, guided in this by his experience on similar 

 parts and h\ the speed of the machines selected for the operation. 



The setting up of the expected output for assembling operations 

 is more difficult, but here also the special training and experience of 

 the engineer along that line of assembly work enable him to set up 

 an expected output which is approximately accurate. In some cases, 

 we go so far as to tear down and reassemble models of the apparatus 

 in order to ol)tain the necessary data. 



The output per hour on each operation enables the engineer lo 

 com|)ule the nmnber of each kind of tool, including spares wliicii 

 must be built, lo [iroduce the retiuired rjuantity of each part. The 

 number of tools required is obviously dependent on the speed <>f the 

 operation, and here again you sec the efTect on tool costs if the engineer 

 fails to select the fastest machine suitable. When it is considered 

 that we have nearly Sli,()()(), ()()() invested in tools for the manufacture 

 of panel machine switching apparatus alone, it can be appreciated 

 wh.it pi, inning means lo us. 



