Table Saw Explained, for the New Woodworker

table saw with accu-fence

Which type is best depends on many factors: such as cost, needs (or lack thereof) for portability and storage and/or Usage in confined spaces. Except for some old and no longer in production models such as Rockwell, all table saws sold for normal use today use a 10" blade and have a 5/8" arbor hole. Cabinet saws are also available with 12" and 14" blades for specialized applications. Contractor's saws can be found with 12" blades from a few firms.As the name implies a cabinet saw has a fully enclosed cabinet for a base. They are designed to be used in a permanent location. Most weigh 350 lbs. or more, with a few weighing in at closer to 700 lbs. With few exceptions, their extension wings are made of flat ground cast iron.

A contractor's saw is on legs that are usually equipped with levelers and/or casters so they can be moved from jobsite to jobsite with relative ease. Contractor's saws never weigh more than 300 lbs., with most weighing in around 250.

Benchtop saws are used on benchtops and seldom weigh more than 50 lbs. They generally have plastic bases as opposed to metal ones as are found on the other types of saws. Out of the box, most contractor's and cabinet saw will rip stock as wide as 25". Benchtop saws will never rip more than 12" wide without some modifications.

Cabinet Saws


A cabinet saw is the heaviest of the 3 types of table saws. It generally weighs in excess of 300 lbs. with the heaviest topping 600 lbs. Horsepower can range from 2HP to 7HP but the vast majority of them are either 3HP or 5HP. Their tables are almost always cast iron and measure 27" or more front to back and a variety of widths from left to right.

Virtually all of them must be equipped with some form of extension wings on both sides of the table itself if a fence with a capacity of more than a 25" width of cut is desired. Aftermarket tables of various materials covered with melamine or other plastic laminate virtually always replace or at least extend the right (and often the left) extension wings as most aftermarket fences ride on the tabletop when moving about.

Contractor's Saws


From the legs up, contractor's saws are pretty much just lighter weight duplicates of cabinet saws with one major exception: motor types. Some use a hang out the back induction motor that can either be ODP or TEFC in design. Others use an enclosed, essentially direct drive, universal type motor. Just like a benchtop saw, these are little more than circular saws bolted into cabinets... but they utilize the same other features as a cabinet saw with regards to table size (exception: the Delta XL10 & Sears 22688 have only a 20" front to back table as opposed to 27"+ for all the others). Contractor's saws can come with flat ground cast iron extensions, cast "egg crate" aka: "grid" ones or ones made of stamped corrugated steel.

Consensus is that the egg crate/grid type extension wings are best suited for pinching fingers, cast iron is the flattest (although, within reason, this is not a factor in cutting accuracy or quality of cut if minor dips occur more than 6-8" away from the saw table itself).

The tables themselves have two parallel miter gauge slots that are universally 3/4" wide x 3/8" deep machined into them: one on either side of the blade. These slots are either regular, simple, "dadoes" or are of the "T-slot" variety that keep miter gauges from tilting out when long stock is used with them. The miter slots must be absolutely parallel to the saw blade for the saw to perform safely and properly. All saws can be adjusted for this but should not have to be if they're new as that's a basic factory assembly adjustment that's hard to duplicate in the field with normal shop tools.

The tables attach to the saw's base by anywhere from 3 to 8 machine screws into threaded holes or bolts and nuts from underneath, depending on the maker. There are two things to look for in a table top when buying a saw: smoothness and flatness.

Smoothness is easy to determine: rub your hand on it. It's either smooth or rough. Some models have such a smooth top as to look like it is chrome plated. Flatness is not so easy to determine. The average person can check for flatness by laying a steel ruler at least 24" long across the top both left to right, front to back and diagonally and looking carefully at the bottom edge for any traces of "daylight" under it.

More scientific persons use a dial micrometer. "Flat" is considered to be no more than .010" "dips" in the table at any spot. Anything less than .030" is considered "acceptable". Anything over that is considered "poor to unacceptable quality" by most engineers testing such things.

Trunnions

Under the tabletop is a gizmo called a "trunnion." This is usually cast iron unit that contains bearings, pulleys and shafts to transmit power from the motor to the blade's arbor. Despite vast improvements in metallurgy in the past 20 years, most people still equate "heavier' with 'stronger' in this category. Not necessarily so but that's something you'll have to take up with each maker's engineering department to find out anyway. Few, if any, normal woodworkers give a damn as long as the things never break. Many people also equate more weight with less vibration...which is true. However, if the rest of the saw's moving parts are well balanced and aligned, there shouldn't be any vibration to worry about dampening in the first place. It is true that the further apart the trunnion are spaced and bolted, the stronger they are. However, in normal every day usage, none of the table saws sold in North America will ever break a trunnion so it's a moot point for the average woodworker.

Note: a simple test for vibration is to turn the saw on with a bowl of water placed on it. Any vibrations will show up as ripples in the water. Another test is to stand a nickel up on edge on the saw's table. If it does not fall over, the vibration is within acceptable limits.


Part II   Arbors, Motors, Fences & Blade Tilting

Part III   Miter Gauges, Throat Plates & Splitters and Guards Table Saw Blade and Dado Blades




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