Thursday, April 26, 2012

V3.17 - Table Saw: Guards ‘n Sawstop

Last week we mentioned fences, but before we get into that, let’s take a look at one of the Table Saw’s most important safety features - the blade guard. There are several components of a blade guard. When talking about a conventional blade guard, there is the splitter, the housing, the mounting brackets and the anti-kickback fingers. One of the newer guard features that has come on the scene recently is the riving knife. While the riving knife has been featured on European saws for many years, it’s relatively new to the USA. Pretty much every woodworker will agree that conventional guards get in the way and are generally a pain in the caboose, but the bottom line is – they DO work. If you use them properly and allow them to do their job, they will prevent you from injuring yourself. Sadly, most woodworkers think they are too smart, too experienced, too ‘whatever’ - insert your own descriptive phrase that means ‘Those are for other folks not me’ - to need one. That’s when they get complacent and find themselves missing a finger or worse. Guards are not just for dummys. As we used to say in the Navy, most safety rules are written in someone’s blood. Guards fit this saying very well. One can be sawing along and have a kickback which throws their hand into the blade and poof, all of a sudden, there is a stump where a finger used to be. It’s NOT a pretty sight. Guards WILL prevent that, but one has to be willing to actually USE them. Nowadays one cannot talk about guarding of saws without mentioning a newfangled invention called “flesh-sensing technology”. The background of this is an invention of one Steve Gass and it is found on saws of his creation that are known as Sawstop. (note: for a video of how this works, just Google “Sawstop hot dog”) The invention itself, is kinda kool, but the politics surrounding it have left many a woodworker confused and some even a bit hacked at Mr. Gass. Once you see the video, I’m sure you’ll be impressed. You’ll see a hot dog slowly passed across a saw table - directly into a spinning saw blade, then, faster than you can saw ‘wow’, the blade will disappear with a loud BANG! Then you’ll see the side of the wiener and it will have a small cut on it. The hot dog represents a person’s finger, which would normally be cut severely and it will only have a small scratch on it. A truly ingenious device. BUT…the method of how this invention has been presented to the market has soured many a folk. Details next time…

Saturday, April 21, 2012

V3.16 - Table Saw: Drives and Fences

Ok, back to the mission at hand - Mr. Table Saw. We had introduced the Table Saw and left off talking about how the motor is connected to the arbor. One thing I might mention, there are several table saws that use a ‘universal motor’ (this motor has brushes inside it, just like your electric hand drill) and some of those motors have a cogged drive belt inside the motor unit. (most of them have reduction gears, not a belt) This gives some folks the opportunity to claim that the saw is a ‘belt-drive’ saw and cheat unsuspecting buyers. Now, technically, they are correct, but in the world of table saws, a universal motor that uses a drive belt is NOT the same thing as an induction motor, with a v-belt and pulley drive system. Ok, to continue our saw drive information; the v-belt and pulley drive system has certain advantages over direct-drive systems. For instance: A- the maximum thickness of wood that can be sawed is greater, because it is not necessary to keep the motor down to allow for motor clearance under the table. All that is needed is room for the arbor pulley and that is a lot smaller, so the arbor itself can get closer to the bottom of the table - therefore, the blade can cut deeper. B- It is easier to change from one motor to another in case of motor failure or in case the saw is transferred from one shop to another with a different power supply. C- A belt-drive saw does not coast as long as a direct-drive saw when it is turned off. This adds to the safety of the belt-drive saw. D- Problems with the saw motor or drive system are far easier to troubleshoot on a belt-drive saw. E- If the saw motor is a true ‘direct-drive’, meaning the blade is mounted directly on the motor shaft AND the motor is an induction motor, it will be a quieter running saw. But if the motor is a ‘universal motor’ with a gear reduction drive, it will be much, much louder. The belt-drive saw is almost as quiet as the direct-drive. There are two methods of accurately guiding the workpiece past the blade: a rip fence and a miter gauge. The rip fence is usually guided by, and mounted to bars that are fastened to the front and rear edges of the table. On some smaller saws, the rip fence is mounted on the table edge itself. In either case, the front rail or front table edge will have graduated markings that tell how far the rip fence is from the blade. The rip fence is used for all ripping operations and is secured during sawing operations by lock knobs or clamp handles. Send your questions or comments to: and we’ll see what we can do to help you.

Saturday, April 14, 2012

V3.14 - Howdy, Mr. Table Saw

Yes, “Mr. Table Saw”…one of the brightest, shining stars in any wood shop, and one of the most necessary. In fact, most wood shops would be out of business if their table saw vanished.
Table saws have been known be various names such as: bench saws, variety saws or stationary circular saws. The table saw is one of the oldest known stationary power tools used in woodworking. It is estimated that better than 80 percent of all woodworking involves sawing, so the value of a clean-cutting precision tool for this purpose is of great value. Anyone who has used a handsaw making a cut and then used a table saw to do the same job knows the value that a powered table saw brings to the operation. Not only is there an increase in production and a decrease in expended effort, there is also a huge gain in accuracy because the machine is designed to minimize the possibility of human error.
The table saw IS the basic machine in any woodworking shop for performing the fundamental operation of “Straight Line” sawing. It is not a difficult tool to operate. Plain ripping and cross-cutting come naturally to most operators, and other jobs requiring more know-how are easily learned. In fact, there are only six basic saw cut in all of woodworking: rip, bevel rip, crosscut, bevel crosscut, miter and bevel miter. All other cuts, no matter how intricate, are combinations of these basic cuts.
The size of a table saw is determined by the largest diameter saw blade that it will accommodate. Popular sizes for home shops and schools can range from 8 to 12 inches. Table saws for industrial use can range in size from 14, 16 or up to 24 inches. Saw cutting capacity is determined by the blade size. For instance, a 10-inch saw will usually cut thru wood 3 and one-quarter inches thick; a 12-inch saw will cut to 4 and one-eighth thickness, with the blade at 90 degrees. The operation of the modern table saw is simple. The saw blade is mounted on a threaded shaft called an arbor that it turned by a motor. Some smaller saws have the blade mounted directly to the motor shaft. The blade projects through a table on which the work is rested. The arbor must be tilted to cut bevels, chamfers and certain types of miters. There is a handle to raise and lower the blade, a device to lock the blade at any degree of tilt or height and a scale to show the degree of tilt. Saws that have the blade mounted directly to the motor shaft are called ‘direct-drive’ saws. The arbor of most saws is coupled to the motor by means of a belt and pulleys.

Send your questions or comments to: and we’ll see what we can do to help you.