This gadget is best used to square tools, fences and general projects. In our shop we mostly use it to set the table saw blade to 90° and it became invaluable tool. It also can measure several angles. This gadget can self-calibrate without the need for external reference for setting 90° angle. For the measurements we are using micrometer that is available from Amazon. Note that most important dimension in this tool is the distance between micrometer measuring rod and reference screws that should be about 10mm (~3/8”). Reference screws should have semicircular heads for better accuracy and they should be tightened to 8/16” from the tip to wood surface. Note that include Reference table values might not be accurate for your gadget and you need to experiment to determine correct values that apply to your build.
This video shows how to build angle measuring gadget using a dial indicator. This device is best used for truing Table saw blade or other 90° angle measurements. It is simple to construct and calibrate. The dial indicator is available from Amazon for about $12.
One easy way to square the miter saw is using angle measuring gadget we build earlier. Using this device we can reliably align the miter saw blade horizontally and vertically. In this video, we square Dewalt DW705 miter saw available from amazon, but any miter saw can be calibrated or squared off with this method.