The twin-spot tool
When faced with the task of cutting a window out of a plate of metal or perhaps cutting out the plates for a skeleton the twin-spot tool is very handy. To make one, start with a piece of steel 1/2in diameter by 4-5in long. Square off the ends then scribe two centre lines at right angles on one end. From the centre of one line mark off two points slightly over l/8in apart and centre pop. Holding vertically, drill down l/8in diameter by l/2in deep at these points. Cut off two pieces of silver steel lin long. Hold in a drill press and file a point on the end of each. Reduce the length of one by 1/64in.
Now harden and temper the points. Insert them into the holder and there you have a twin spot. In use, scribe a line 3/32in inside or outside the cut-out line, centre pop on this line then pop all the way round with the twin spot. Use a 1/8in drill to drill through at these points then shear the webs through with a piece of broken hacksaw blade. Job jobbed.
G Reynolds, UK
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