The right tools for playing all the angles
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= GoodThey say the devil lives in the details, but woodworkers know the pointy-tailed imp’s street address–the corner of Bevel and Miter. The problem with these angled cuts is that minute errors can multiply within an assembly. A fence, gauge, or blade that’s off by even a fraction of a degree can make the difference between a finished frame and firewood.
Armed with a few appropriate angle gauges, you can keep that devil at bay. The key to selecting the right tool is understanding the three different, but equally-important challenges faced by angle-setting instruments. They include the ability to measure an angle, to transfer or lay out an angle, and to set machine components to specific angles. No tool excels in all three categories, but once you understand which type performs a job best, you know which one to reach for (or buy).
Bevel Gauge
A bevel gauge, or T-bevel, offers great flexibility in a strictly mechanical tool. The sliding blade can be adjusted to fit into tight corners and can be solidly locked for machine setup or joint layout. After making a cut, the bevel gauge can then be used to check its accuracy.
While this simple tool excels at transferring angles, it falls short when you have to set it to a specific angle, adjust an angle by a few tenths of a degree, or determine the numeric value of an angle that it’s holding. For that, you need to read the angle of the gauge using a triangle, protractor, or square. To avoid that two-step procedure, many woodworkers these days are turning to digital gauges.
Digital Bevel Gauge
Incorporating an LCD readout into an otherwise typical bevel gauge brings a time-honored tool into the digital age of woodworking. The gauge can be used in traditional fashion for measuring and transferring angles, as well as setting machinery. However, unlike a traditional bevel gauge, determining the quantitative angle doesn’t require outside assistance. Instead, you can read it on the tool’s display (accurate to 0.3°). This allows you to set up a cut by simply angling your tablesaw blade, miter gauge, or power mitersaw so that their scales match the angle reading on the T-bevel.
The digital readout also allows easy angle adjustments on the fly. For example, if you accidentally knock the bevel gauge blade out of its 47° position, it’s easy to nudge it back in place instead of returning to the reference workpiece or taking a repeat reading from a protractor.
Analog Protractor
This tool is designed to make your life a little easier when setting up your mitersaw to cut angles for bisected miters. The dial’s large arrow indicates the primary angle (the tool’s leg splay). The smaller arrow notes the angle at which to set your saw, using the machine’s scale. For example, to join two frame pieces at 135°, the protractor tells you to set your saw’s pointer to 22 1⁄2°, which will cut the complementary 67 1⁄2° angle on the workpiece. Cut two frame members at that angle, and join them to create your 135° frame angle.
This tool has the quantitative advantage over a standard bevel gauge, although digital gauges still have the edge on precision. For measuring and laying out, you’ll still want a T-bevel, as the protractor’s long arms can’t fit into tight corners. Also, the tool lacks a locking knob. Although the arms are usually stiff enough to hold an angle, they can slip during layouts.
Digital Angle Gauge
This magnetic gauge wins hands-down for easily and precisely setting the angle on machine components such as tablesaw blades, bandsaw and drill press tables, and jointer fences. Simply rest (or magnetically attach) the cube against a reference surface (e.g. the saw table), and press the reset button to zero-out the internal level. Then attach the gauge to the other reference surface (e.g. the saw blade), and set your desired angle, referring to the digital readout. The gauge is easy to attach and read, even in poor light. (Of course, when the battery dies or the electronics fail due to a hard fall from the bench, you’re out of luck.)
Despite its advantages at setting machinery, this digital gauge isn’t convenient for measuring angles on workpieces, and it’s simply not suited to marking out joints.
Double-Duty Drafting Tools
Odds are good that you already have some handy angle-setting tools sitting in a desk drawer. If not, you can buy them at an art store for a few bucks. Partner a plastic protractor ($3-6) with a pencil and you can set your T-bevel with precision. With a built-in lock knob, adjustable triangles (about $10) are equally useful for providing precise measurements and transferring angles. Metal square head protractors are good for laying out angles on paper and stock. The long arm also works for measuring small angles, such as the bevels on chisels and plane blades.
