Sometimes cumulative error can be your worst enemy, and other times it can be your best friend. You’ll love it when you use it to set your table saw fence! When you’re done you’ll have set your fence five times more accurately than any other way I know. Here’s what you do:
Stack the five pieces edge-to-edge and take a measurement. If the total measures 10″, your fence is set perfectly already. If it’s less or more than 10″, then you need to adjust your fence position pointer in the appropriate direction, do the test again, and keep testing until your total is exactly 10″. The beauty of this technique is that you’re measuring cumulative error. If you cut one piece, are off by 1/64″, and measure it, you may not notice the error. But an error of 1/64″ per board accumulates to 5/64″ in five boards, an error you can easily see when you measure.
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