84 



THE WORLD'S ADVANCE 



screw, J, which passes through the block 

 H, and is held in position by the nuts, K. 

 The rachet, W ' , is held in place by the 

 hexagonal nuts, L. 



The opposite end of the rachet rod 

 revolves in a bearing GI. An adjusting 

 knob, M, of rubber or brass, is held in 

 place by hexagonal nuts, N. 



In operation, the base, B, is pinned to 

 the drawing board at whatever angle is 

 desired. A line is drawn across the 



straight edge, D, the knob, M, is turned 

 until the rachet clicks, when the rule 

 will have been moved far enough to the 

 right for another line to be drawn. If 

 a wider space between the line is desired 

 than a single action of the rachet wheel 

 provides, the knob may be turned until 

 the spring clicks twice, or three times. 

 Care must be taken then, of course, that 

 the number of rachet spacings is borne 

 in mind at the beginning of each line. 



Centering Tool 



An idea which will be found useful 

 by mechanics for centering rough stock 



j'fj/of t{ long. 



is shown in the accompanying sketch. 

 The tool should be fashioned from tool 

 steel or cold rolled steel, case hardened. 

 A rod, 3^6 inches long and 1^2 inches 

 in diameter, should be adjusted in the 

 lathe chuck until it runs true. After 

 centering, a 1 5/64-inch hole should be 

 drilled entirely through and reamed out 

 with a y^ -inch reamer, after which the 

 front end of the piece should be cut out, 

 as shown, until the large opening meas- 

 ures 1^4 inches across. This should be 

 smoothed carefully. The opposite end 

 should then be cut to a diameter of % 

 inch and a 3/i6-inch hole drilled, tap- 

 ped and countersunk. 



The plunger, B, should be made from 

 hard steel, machined to a point at one 

 end so that a 30 degree angle is formed, 

 and a slot, J^-inchx i^ inch, milled in 

 the center. The slot prevents the plunger 

 from sliding out after the 3/1 6-inch 



screw is set in its proper place. 



The screw, C, should be turned in the 

 lathe at the threaded end so that it will 

 fit in the slot of the plunger. 



In use, the tool is fitted over the end 

 of the stock to be centered, and a sharp 

 blow struck with a hammer on the pro- 

 truding end of the plunger. 



Contributed by 



JAMES MC!NTYRE. 



Handy Lock for Lathe Rest 



A quick-acting lock for a wood-lathe 

 rest is illustrated in the accompanying 

 drawing. The rod, A, should have a 

 diameter of approximately 24 inch, and 



have a slot at one end to admit the cam, 



B. The washer, C, should be cut at the 



center to fit loosely over the slotted bolt. 



Contributed by M, A. PIPER. 



