350 



THE WORLD'S ADVANCE 



POWER HACKSAW 



SAW CARRIAGE 



NOTE ShoJL 



Thru Ho/tLs x o-nct X 



HflCK SflW FRRME. 

 '*7/Q' Mate.na.1. 



pitman wheel is ten inches in diameter. 

 An eight-inch stroke is about the proper 

 length for ordinary work with a 12" blade 

 in the frame. A shorter or longer stroke 

 is easily obtained by varying the location 

 of the 5/16" x 1 1/2" lag screw which is 

 used to fasten the end of the pitman rod 

 to the wheel. 



PULLEY WHEEL: This may be some- 

 thing on hand or worked up for the 

 need. The size of it must be varied to 

 secure a speed of about 45 strokes per 

 minute. 



SHAFT : A piece of i" cold rolled steel 

 is used for this. If tight and loose belt 

 pulleys are to be used it should be of a 

 suitable length to accommodate them. 



A half-inch lag screw should be run in 

 from the rim of the pitman wheel and 

 into a hole countersunk into the shaft for 

 it. This will secure the wheel in its place 

 and effectually prevent all slippage. A 

 very neat job may be made of the set 

 screw by sawing off the head and then 

 sawing a slot in the end thus left, to 

 serve as a hold for the screw driver when 

 tightening it. 



SLIDING WEIGHT : Some y%" pipe and 

 fittings were used for this, as shown in 

 the drawing. The weight itself is merely 

 the front j-aw off the old discarded ma- 



chinist's vice from which the 

 screw was taken. A set screw 

 is provided to keep this in place, 

 though it is not absolutely es- 

 sential. 



LEVER: This is provided for 

 raising and holding the saw 

 away from the work. 



BRACKET: An iron bracket 

 is provided as a guide for the 

 front end of the saw carriage. 

 It is merely to prevent any later- 

 al movement of the carriage in 

 actual use. This is shown fas- 

 tened on cleat X on page 348. 



This saw has been in almost 

 constant use for nearly one year 

 and is giving good satisfaction. 

 Perhaps the heaviest duty it has 

 done was when it was used to 

 slot an armature for an electric 

 motor. In this case 16 slots, 

 each y 4 " wide, ft" deep and 3^" 

 long were cut. Six blades were 

 used in the saw at one time to 

 give the proper width to the grooves or 

 slots. 



An Easily Constructed Arc Lamp 



A self-operating arc lamp, which can 

 be made of simple materials, can be con- 

 structed as follows : 



An L-shaped brass standard, (7, of 

 heavy stock should be machined or cast 

 and fitted with a brass binding post, D, 

 and bored with holes for the carbon, A, 

 and a set screw to hold the carbon in 

 place. The other carbon, B, slides in a 



