Selena Gordon Table Saw August 24th, 2018 - 09:15:16
The motor, trunnions, arbor assembly, and gearing make up the essential mechanical components of the saw. These quality and robustness of these components varies considerably and can greatly impact the durability of the saw, its capacity for cutting heavy stock and its ability to stay in adjustment and hold settings.
The size of the cast iron table saw top is also important: the larger the better. When you are sawing large objects, you want as much flat table surface as you need to support the work piece flat to the blade for accuracy. Larger table size is usually accomplished by attaching cast-iron table wings to the edge of the main table. These wings must be as flat as the table and the seam they create must be aligned so that the top of the wing is flush to the table saw table along its entire length.
One table saw manufacturer I know believes in "aging" its cast iron machine table tops before milling them flat. The tops are cast and then left outside in a "bone yard" to bend, bow, warp and twist in the sun and rain for a year or so. Then, they are brought inside where all the rust is removed and the table top is ground absolutely flat and polished to sheen. The theory is that the metal needs to settle into a place where all post-casting movement has ceased and that the table should not be ground flat before this is done. Otherwise, the table may move out of absolute flatness after it is part of your new table saw and that it not at all desirable. Why? Because the flatness of your table saw top will determine the accuracy of your cuts. Be sure to check your new table saw for table flatness with a straightedge on or before delivery and afterwards from time to time. Lay the rule across the table top at all angles and check for daylight under the rule or rocking of the straightedge on the table top.
If you're in the market for a table saw, you'll have a number of options and features to consider. To make the best decision, a basic understanding of the "inner workings" of this woodshop standard is essential. Below, I'll describe the primary table saw components, what makes them important, and what to look for when it comes time to buy.
Beginning at the bottom, the table saw base houses the working parts of the saw, including the trunnions, the arbor assembly, the sector gears, and sometimes the motor. On some saws, the base is a "cabinet" type, meaning that a fully enclosed base extends all the way to the floor. Other saws have an open base, meaning that the base consists of a metal box that surrounds the internal working parts of the saw on four sides, but not the bottom. Open base saws have legs that extend downward from the bottom of the base to the floor.