THE WORLD'S ADVANCE 



349 



place by means of the half-inch 

 bolt which passes through both 

 of them. Loosening this bolt 

 permits of adjusting the jaws to 

 accommodate the stroke of the 

 saw to the work. The front 

 jaws are also held together by 

 means of a half-inch bolt which 

 is kept just tight enough to allow 

 the jaws to slide back and forth. 



The vise screw is taken from 

 an old broken vise. The nut is 

 fastened to the top one of the 

 front jaws by means of bolts. A 

 washer is placed on the screw 

 on the inside of the cleat X and 

 a 3/1 6" hole drilled for a pin on 

 the outside of this washer. This 

 prevents the screw from forcing 

 back through the cleat as the 

 vise is tightened. 



SAW CARRIAGE: In working this up 

 it is necessary to bear in mind the work 

 to be handled. It is designed to fit be- 

 tween the bearing supports which have 

 been previously described. It is at- 

 tached to the frame and supported en- 

 tirely by means of the shaft passing 

 through the two holes shown in the de- 

 tail on page 350. Inasmuch as these 

 support much of the weight of the car- 

 riage, and the shaft turns in them, they 

 should be arranged as bearings and pro- 

 vision made for oiling them. 



The saw carriage is held together by 

 means of J4" dowel rods, which are held 

 in place by means of screws. Two iron 

 braces are also fastened on, as suggested 

 in the detail, to insure the rigidity of the 

 frame. These braces are of %" x i" 

 iron or mild steel. 



Especial care should be used to have 

 the space for the slide true and smooth. 



SLIDE: This is very simple. Four 

 iron plates are fastened on the wood 

 block, as suggested in the sketch. Either 

 screws or bolts may be used for this. 

 The holes shown cut in the ends of the 

 wood block fit the frame which holds the 

 saw. 



HACK SAW; FRAME: This is also 

 detailed. As in all frames of this na- 

 ture, provision must be made for tight- 

 ening the blade. In this case threads 

 are cut on a 5/16" piece of cold rolled 



POWER HACK SAW 



77?flL SUPPORT ^^^^ 



CLEAT x 



BEARING 



steel or iron. A pin for holding the end 

 of the blade is riveted in one end of this 

 piece. This end of the bolt, as it may be 

 called, should have no threads on it, but 

 instead should have the side the rivet 

 projects from filed flat, thus permitting 

 the saw blade to come to the center of 

 the frame. This will also keep it from 

 twisting. The threaded portion of the 

 bolt is next filed square, preventing it 

 from turning in the frame as the nut is 

 tightened, as well as holding the blade 

 in alignment. 



The frame itself needs little descrip- 

 tion. It may be made as shown or worked 

 up from a piece of quarter-inch material. 

 The method shown requires that the parts 

 be riveted together. The end opposite 

 the bolt has a small piece of %" x %" 

 material riveted in. This in turn has an- 

 other pin, for holding the saw, riveted 

 into it. A clip of the same material is 

 made and riveted onto the frame just 

 above this piece. This clip has a hole 

 drilled through its open end to allow for 

 connecting the end of the pitman rod. 

 A 3/1 6" pin is about right for this. 



PITMAN ROD : This is marked P R on 

 page 348. It may be made from solid 

 stock, or l /%" x %" stock may be doubled 

 for it. The length should be figured after 

 the rest of the machine is assembled. 



PITMAN WHEEL : Made from 2" maple 

 or oak, as is also the pulley wheel. The 



