Straight out of the box all parts had flat faces. I checked this using a straight edge and feeler gauges. The overall construction of the gauge is solid. All parts fit securely in place. Assembly is quick and easy.
First apply the non-stick tape to the bottom of the gauge to make it slide smoothly across the table. The triangle frame of the gauge just snaps together.
You have the option to apply grip tape to the face of the fence. The grip tape is not smooth, but still supports the workpiece parallel to the true face of the fence.
Calibrating the miter gauge
Squaring the gauge is done using an Allen wrench and a wrench. It can be accomplished reliably and accurately within seconds. Begin by set the gauge into the T-slot of your table saw. Check if the fence is square to the blade using a square.
If it is not, loosen the eccentric adjustment screw at the bottom of the gauge. Rotate the adjuster with a 3/4" wrench. The fence will move. When it is square to the blade, tighten the set screw.
The guide bar is ~21 inches long. 3 adjustment slots are spaced out evenly along the bar. The bar rides evenly in the T-slot of your saw even when the gauge is partially withdrawn. This is inevitable due to the triangle construction of the gauge. More often than not at least some parts of the bar is unsupported when I start my cuts.
While this is not really a problem in itself and normal operation of the gauge, it does take some time getting used to. In this state the gauge has some up and down play. Eventually pushing the gauge through a cut becomes simple thanks to the excellent hand grip and low friction tape.
The triangle construction of the Osborne EB-III is both this greatest asset and, in my opinion, the source of the most significant problem of the gauge. On the positive side, the triangle construction creates a rigid fence. The fence will not move during normal operation. Only excessive force will dislodge it. The set screw holding it in place will eventually slip.
The angle adjustment is located at the bottom of the miter gauge. The adjustment arm is held in place by a set screw. To adjust he angle of the gauge, loosen the screw, adjust the angle, and re-tighten the set screw. An angle gauge is printed on the adjustment arm.
To set the gauge at a predefine angle such as 45 degrees, move the gauge to the 45 degree mark and press a plunger located at the bottom of the adjustment arm. This is intended to move the adjustment arm into the exact position required for a 45 degree fence angle.
Unfortunately there is some play in the this system. When the plunger is pressed the fence can still be moved by a fraction an inch. While this results in less than a 10th of a degree in variance, I would prefer to see a more reliable mechanism here. Even the gauge included with my table saw can be set accurately to 0 degrees. The Osborne EB-III can't. It's important to note that this amount of play will not be significant in all but the most demanding jobs.
The gauge's fence has multiple adjustments. Each is held in place using set screws. When tightened the screws the adjustments are locked in place. They don't budge. The same can be said of the extendable part of the fence. It won't stay on the same plane as main fence when pressure is applied, but it will not move laterally. Since the main fence supports the work piece, the play in the extension fence is not a big problem.
At the top of the gauge is a T-slot for hold-down and a measuring tape. The tape is pretty much useless. The instructions that come with the gauge say so themselves. Osborne claims it is useful as a quick reference. For that, it is too short for me.
A flips stop rides in the T track at the top of the fence. It is square to the fence's surface and large enough to function well. It is held in place using a set screw.
Attaching an auxiliary fence to the gauge is a none starter. The gauge does not have the mounting points for this. Besides, it already has an extra large fence. If you use custom fences a lot in your work, the Osborne EB-III is not for you. Hold on to your old miter gauge for these situations.
Overall the Osborne EB-III is a good miter gauge. The large fence provides great support for the work piece. The flip down stop and extension fence makes cutting larger pieces a snap. Preset angle clicks make adjusting the fence simple.
Unfortunately the predefined stops are not perfectly accurate. For most woodworking operations this will not matter. The gauge itself is durable and will provide many years of trouble free service. I recommend the Osborne EB-III to any hobbits. It is a significant upgrade to the standard miter gauge.
Manufacturer's site: http://www.osbornemfg.com