Table Saw Explained, Part III
Table Saw Explained, Miter Gauges, Throat Plates, and Blades
If you have a miter saw or a radial arm saw, you'll seldom use a miter gauge. If you don't, you'll use one all the time for making cross cuts in wood, especially angled cuts. All table saws come with one. Most are OK for setting angles with a fair amount of precision. All will hold at 45 and 90 degrees, thanks to preset stops. After market ones that are better constructed are easier to set at in between angles. The main thing to look for is that the one you use rides smoothly in both slots without any noticeable binding or side play while moving.
Note: benchtop saws have varying size gauge slots, seldom over 3/16" deep. No aftermarket gauges exist for them and the factory supplied ones are notoriously inaccurate and flimsy.
Throat plates are the removable metal pieces that your saw blade protrudes thru. All saws come equipped with one that will work for cuts using a standard blade set to cut at any angle. If you use a dado blade, you'll also need a dado throat plate. If you also use a molding cutter-head, you'll need a 3rd one for that work.
Throat plates should fit snugly in their slots and be adjusted precisely level with the tabletop for optimum performance. "Zero clearance" throat plates work much better than factory supplied ones for 90 degree blade angle cuts. Primarily, they eliminate tear-out on the bottom of the work piece and prevent small cutoffs from wedging between the throat plate opening and the spinning blade. Plastic ones for all popular saws available, but making them yourself out of wood is not hard.
Simply cut or plane a 4" wide x 12" long piece of hardwood to the thickness of your factory plate. Rough cut its shape using the metal one for a template. Use the metal one as a pattern for an edge trimming router bit to cut it precisely to size or carefully sand it to size. Insert a short finishing nail in the front edge where the metal "tit' is on the original. This keeps the thing from flipping up when weight is placed on the back end of the throat plate. Most people drill and countersink 4 holes over the flanges in their table saw and use #4 or #5 screws as levelers.
Anne Watson had the neat idea of making the plate a little too thin, putting some caulk on the flanges, pressing the plate level and letting it dry overnight. To cut the blade slot, use a smaller diameter blade ...like the left or right cutter on a stack dado or a wobble dado set at "0" width. Move the edge of the fence or clamp a scrap 2 x 4 over the plate and slowly raise the spinning blade thru the wooden plate. Once made, they tend to last for a year or more with daily use.
Splitters and Guards
Splitters attach behind the blade and keep stock from "pinching" shut as it exits the saw blade. All factory-supplied ones are a pain in the rear to put on and off and they do need to be taken off to make most rabbet and dado cuts, as well as many specialty cuts. Aftermarket ones that flip out of the way or come off with ease are available, if you're not real comfortable and knowledgeable around saws, we highly recommend the use of one or the other.
Guards are another thing entirely. The standard equipment guard is often poorly designed and often more of a hindrance than a help. We recommend that you use push sticks and feather boards on as many of your cuts as possible and know where your hands are in relation to the blade at all times if you do not use this item.
Note: Dado blades cause more than 70% of all major table saw kickback and injury. Carelessness causes 100% of them, regardless of operation being performed.
Table Saw Blades
Table saw blades come in two basic thicknesses, .126" for standard carbide and .097" for thin kerf. Steel blades, which, in some configurations, cut much smoother than carbide, do not last very long so we are not going to waste our time talking about them here. The blade that comes on most table saws is steel. It makes a nice wall clock. It does not make a good Frisbee. It makes an even worse blade to cut anything with. Pitch it at your earliest opportunity and buy two blades: A good thin kerf rip blade and a 60 tooth ATB or TCG for crosscutting. Under normal usage in a home shop, these will last you for years before they need sharpening or the need for another type comes up.
There are 4 basic types of tooth configurations in saw blades: ATB (alternating tooth bevel), TCG (triple chip grind), FTG (flat top grind) and "combination"...which is usually 4 ATB teeth and one FTG "raker" tooth to smooth the edges of the cut.
As a rule of thumb, the more teeth on the blade, the smoother it cuts. At the same time, the more teeth, the more friction, and the more power needed to cut with. Most rip blades have 24 teeth. Most crosscut blades have 60 teeth. Combination blades have 50 teeth. Combination blades are designed to both rip and crosscut but they generally don't do either real well. TCG blades are designed for cutting plastics, MDF and man made materials. They last 3-5 times as long as ATB blades and most commercial shops use them exclusively to do all but the most strenuous ripping of heavy thick stock.
Carbide blades last a minimum of 30 times longer than steel ones, although they do not cut as smoothly. Most can be re-sharpened a minimum of 5 times. Many survive 10 or more re-sharpenings. The better ones have laser cut bodies and laser welded carbide tips. The cheaper ones have stamped bodies and soldered tips.
Thin kerf blades require less horsepower but are more prone to "wobbling" under strain. For this reason, most users of thin kerf blades use blade stiffeners (or dampeners), that are 1/8" thick steel washers about 4" in diameter that fit on either side of the blade when it's bolted to the arbor. If you use these, be sure and reset your fence's cursor to allow for the 1/8" movement. Of course, this will also require that you make another "0 clearance" throat plate if you use one of those.
Carbide, while extremely sharp and durable, is extremely fragile. Be careful not to drop, hit or otherwise mess with your carbide tipped blades as replacing a chipped tooth is often almost as expensive as buying an entire new blade.
There are 3 basic types of dado blades: Stack, V-wobble and wobble. The only good ones for cabinet and furniture type work are the stacked variety of the anti-kickback variety. These come in 6", 8" and 10" diameters from a variety of makers. Consensus is that a 6" version is adequate for most tasks, although most professional shops use the 8" versions.
Return to Part I: Table Saw Explained, For the Beginner
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