10 - Heavy Duty Lathe Stand, страница 24
TECHNIQUE Center Finding Tips CENTER OF A ROARO Quick, what's the center of a board that's 5n/32"-wide? Or i3/i6"-thick? Here's a trick to finding the center without any complicated division. First, position the "0" end of your rule at one end of the work-piece, see Drawing. Then angle the rule so the other end rests on a number easily divisible by two — the halfway point is the center. CIRCLES Finding the center of a something round is easy with this simple jig, see Drawing. Just clamp a combination square to a framing square. To use it, position the framing square so both 'legs" touch the workpiece. Then draw a line along the top edge of the combination square. Now rotate the workpiece and mark another line to locate the center. RECTANGLES & SQUARES If you've ever had to mount a knob centered on a drawer front, you know how tricky it can be to get it exactly in the center. The answer is simple — don't measure anything. Instead, draw a pair of diagonal lines from corner to corner to quickly locate the center. Note: This tip works for both square as well as rectangular workpieces. IRREGULAR SHAPES To locate the center of a work-piece that isn't square (such as a turning blank), I use a shop-made template. It's just a piece of Plexiglas with circles scribed in the surface, see Drawing. To use it, place it on the work-piece so the largest possible circle fits inside the edges of the work-piece. Now use the center of the template to mark the workpiece. THIRD: draw- two lines to locate center SECOND: position framing square so both legs touch the workpiece FIRST: clamp combination square to framing square 24 ShopNotes No. 10 |
