CHAPTER XXXV 

 POWER WOOD-WORKING MACHINES 



497. Kinds of Machines. Wherever possible, hard work 

 is done by machinery. This is particularly true in the manu- 

 facture of the movable parts of a building, such as doors, 

 sashes, window-frames, etc. Most work of this kind is per- 

 formed by means of band and circular saws, jointers,. planers, 

 lathes, and machines for sandpapering and for making mold- 

 ings and tenons. The more simple machine processes consist 

 of such operations as " knocking out cores/ 7 i.e., cleaning the 

 mortises or slots made by the mortising machine ; wiring slats 

 on rods for blinds; "coring out" or boring holes for blind 

 slats; making slats and small moldings for door paneling; 

 and so on. 



Since machinery is so extensively used in carpentry work, 

 a knowledge of the construction and operation of wood- 

 working machines is very necessary to the wood-worker. 



498. Power Saws. Power saws may be classified under 

 three heads circular, band, and scroll or jig. The circular 

 saw is used for sawing off, ripping, and the cutting of various 

 angles. The blade is held on a spindle or arbor which is 

 driven direct by a belt pulley fastened to the same shaft. 

 The arbor is usually supported by a frame, which in turn 

 supports the saw table. 



The band saw is used entirely for sawing curves and irregu- 

 lar shapes of various kinds. It consists of an endless band 



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