Accurate bevel cuts are a relatively easy cut to make on a table saw if the saw has been properly set up and in good alignment. I shudder at the thought of how many people buy expensive table saws, un-box them in their shops and just start using them without setting them up properly. I shudder at the thought of how many woodworkers use a table saw for years at a time without realigning them properly. I shudder at the thought of how many ÃƒÂ‚Ã‚Â“seriousÃƒÂ‚Ã‚Â” woodworkers will change a table saw blade, miter cut guide or rip fence without checking the alignment afterwards. I shudder at the thought of how many serious woodworkers use makeshift gauges to check their table saw alignment when they do check it. I shudder at those thoughts because these woodworkers are not only ruining some really beautiful and very expensive wood, but using a saw thatÃƒÂ‚Ã‚Â’s not properly aligned is positively dangerous. A badly aligned saw is dangerous no matter what kind of cut the woodworker is making but itÃƒÂ‚Ã‚Â’s especially dangerous when making a bevel cut using the rip fence as a guide because the waste cut is below the blade and trapped between the underside of the blade and the rip fence.
Many woodworkers use a board to check to see if the rip guide is parallel to the blade but that a dangerous of checking blade alignment when you are setting up to do a bevel cut. If the blade and rip guide are out of parallel by as little as 0.5ÃƒÂ‚Ã‚Â° (degrees) the waste cut trapped under the blade and between the underside of the blade and the rip guide can jam and kick back on the saw operator. When that happens, the best case scenario is a ruined piece of wood. The worst case scenario is the saw operator is seriously injured by the flying wood. IÃƒÂ‚Ã‚Â’m a firm believer in using the proper tools for the job IÃƒÂ‚Ã‚Â’m doing and IÃƒÂ‚Ã‚Â’m assuming that my readers are the same. The proper tools for checking the setup of a table saw arenÃƒÂ‚Ã‚Â’t cheap but neither are they overly expensive, especially if you take into consideration what being impaled by a piece of flying hard wood might mean to you or a loved one. These same tools can also be used to align your radial arm saw.
Special tools that you will need.
ÃƒÂ‚Ã‚Â· Master Gage Master PlateÃƒÂ‚Ã‚Â™ ($49.00)
ÃƒÂ‚Ã‚Â· Master Gage Super BarÃƒÂ‚Ã‚Â™ ($69.00)
Both of these tools are available from MasterGage.com. These tools come with detailed instructions on how to use them so IÃƒÂ‚Ã‚Â’m simply going to give some general information on them and on how to use them here. You can also download their manuals in pdf format using these links for the Master Plate manual and the Super Bar manual.
The Master Plate is a 6ÃƒÂ‚Ã‚Â” X 10ÃƒÂ‚Ã‚Â”, 3/8ÃƒÂ‚Ã‚Â” precision ground aluminum plate that replaces your table saw blade during the alignment process. This plate is precision machined so that both faces are perfectly flat and perfectly parallel to each other. The plate is engineered for use on table saws with both 5/8ÃƒÂ‚Ã‚Â” and 1ÃƒÂ‚Ã‚Â” arbors. Holes for both those arbor sizes are located on both the long and short sides of the plate so it can be used vertically to check bevel stops and horizontally to check alignment between the blade and the rip fence.
The Super Bar is a very accurate dial indicator designed to mount and ride in the miter gauge ItÃƒÂ‚Ã‚Â’s adjustable to fit both the standard 0.750ÃƒÂ‚Ã‚Â” miter gauge slots and the undersized 0.740ÃƒÂ‚Ã‚Â” slots found on Craftsman table saws. The mount has both coarse and fine adjustments set screws as well as a set of outriggers for added accuracy and stability.
The basics of table saw alignment using the SuperPlateÃƒÂ‚Ã‚Â™ and SuperBarÃƒÂ‚Ã‚Â™.
The miter slot is the key to the alignment procedure. With the exception of some really inexpensive bench top saws, the one thing that all table saw have in common is the Miter Slot. These slots are the key to the use of many table saw accessories, miter guides, sleds, and many shop made as well as commercial jigs. This slot determines the path of travel that the work piece will take across the table, so all our measurements will be made in reference to this slot.
First things first
The miter slot is fixed in place in the cast iron table and isnÃƒÂ‚Ã‚Â’t adjustable but we may have to tweak it so the tight fitting miter gauge guide or other accessory using the slot slides easily and smoothly. These slots can have slight irregularities in width that cause the accessoryÃƒÂ‚Ã‚Â’s guide bar to bind. These irregularities in width are easily corrected. To correct these irregularities follow these steps.
ÃƒÂ‚Ã‚Â· Mark where the guide bar tightens up. This will usually be near the front of the slot.
ÃƒÂ‚Ã‚Â· Wrap a piece of 150-grit sandpaper around a piece of ÃƒÂ‚Ã‚Â¾ÃƒÂ‚Ã‚Â” thick wood and sand the area. As a rule these area are very short and the amount of material that you will need to remove is in the neighborhood of the 0.003ÃƒÂ‚Ã‚Â” to 0.005ÃƒÂ‚Ã‚Â” range, so go slowly. Stop, wipe the slot free of the sanding debris and check guide bar movement frequently. You can always remove more if the bar still sticks but you canÃƒÂ‚Ã‚Â’t put any back on if you remove too much.
Second, remove the blade and check the sawÃƒÂ‚Ã‚Â’s arbor for runout
After removing the blade clean the arbor and arbor washers of all sawdust. Re place the arbor washers and nut on the arbor shaft. Mount your dial indicator and check for arbor shaft and the inbound arbor shaft washer for runout. Turn the arbor shaft by pulling slowly on the drive belt, stopping often to let the dial indicator to relax. As you turn the arbor shaft, the highest deviation from zero should not exceed 0.002ÃƒÂ‚Ã‚Â” or that specified by the sawÃƒÂ‚Ã‚Â’s manufacturer. If it does the arbor shaft will have to be replaced because an arbor shaft with excessive runout will make all attempts to properly set up a table saw futile.
Third, mount the MasterPlateÃƒÂ‚Ã‚Â™ on the arbor in the vertical position.
Using an accurate speed square, adjust the 45ÃƒÂ‚Ã‚Â° and 90ÃƒÂ‚Ã‚Â° stops. The bevel angle scale on table saws are only meant for rough settings, itÃƒÂ‚Ã‚Â’s always best to use a good angle finder for fine adjustment that are required for fine woodworking.
Fourth, switch the MasterPlateÃƒÂ‚Ã‚Â™ to the horizontal position and check for parallelism.
ÃƒÂ‚Ã‚Â· To check for parallelism place the tip of the SuperBarÃƒÂ‚Ã‚Â™ rod ÃƒÂ‚Ã‚Â¼ÃƒÂ‚Ã‚Â” from the front edge of the plate and zero the needle.
ÃƒÂ‚Ã‚Â· Slowly slide the SuperBarÃƒÂ‚Ã‚Â™ along the miter slot until it reaches ÃƒÂ‚Ã‚Â¼ÃƒÂ‚Ã‚Â” from the rear edge.
ÃƒÂ‚Ã‚Â· The goal here is a 0.000 difference but most manufacturers allow for a difference =<0.001ÃƒÂ‚Ã‚Â” or a difference equal to 0.001ÃƒÂ‚Ã‚Â” or less.
ÃƒÂ‚Ã‚Â· If the difference is greater than 0.001ÃƒÂ‚Ã‚Â”, you will need to realign the arbor shaft. Check the manual that came with your saw to see how thatÃƒÂ‚Ã‚Â’s done.
Fifth, check the alignment of the rip fence to the miter slot
ÃƒÂ‚Ã‚Â· Remove the MasterPlateÃƒÂ‚Ã‚Â™ and slide the fence towards the miter guide slot until the probe of the SuperBarÃƒÂ‚Ã‚Â™ is depressed about ÃƒÂ‚Ã‚Â½ÃƒÂ‚Ã‚Â” to place tension on it.
ÃƒÂ‚Ã‚Â· Slide the SuperBarÃƒÂ‚Ã‚Â™ to the front of the miter slot and zero the dial indicator.
ÃƒÂ‚Ã‚Â· Slide the SuperBarÃƒÂ‚Ã‚Â™ to the rear of the miter guide slot and note the reading. A negative reading here i.e.-0.003, means that the rip fence is tailing in towards the blade, the very situation that causes kickbacks. A positive reading i.e. +0.003 means that the fence is tailing away from the blade. No worry here about dangerous kickbacks but the fine fitting joints that you are looking in fine woodworking will be ruined.
ÃƒÂ‚Ã‚Â· Our goal after adjusting the rip fence alignment is a difference of 0.000ÃƒÂ‚Ã‚Â” between the front and back of the guide slot but anything between 0.000ÃƒÂ‚Ã‚Â” and +0.001ÃƒÂ‚Ã‚Â” is acceptable. A negative or tail in reading of any degree is never acceptable.
Sixth, Mount the blade that you will be using and check the blade for runout
Saw blade can warp and bend with use, so itÃƒÂ‚Ã‚Â’s a good idea to check them regularly. As always our ideal runout is0.000ÃƒÂ‚Ã‚Â” but anything between 0.000ÃƒÂ‚Ã‚Â” and 0.003ÃƒÂ‚Ã‚Â” is acceptable.
Seventh, check the alignment of the miter gauge with the miter gauge guide slot.
I use a 14ÃƒÂ‚Ã‚Â” artist square for this task because they are relatively inexpensive and very accurate. Many saw manufacturers recommend that you use a carpenterÃƒÂ‚Ã‚Â’s framing square for this alignment procedure, which is fine as long as the carpenterÃƒÂ‚Ã‚Â’s square is perfectly square. If you want to keep a framing just for this purpose, fine, but I wouldnÃƒÂ‚Ã‚Â’t trust the one I use day in and day out doing rough framing work because they do get knock about and they have a tendency to become less than perfectly square.
Eight, align the splitter
Align the splitter so that itÃƒÂ‚Ã‚Â’s centered on the blade using a narrow kerf blade. This is very important because if the splitter is at an angle to the bladeÃƒÂ‚Ã‚Â’s center, it will cause the work you are cutting to bind as it slides over the splitter.
Last, but not least
You are almost done but before you and your saw are ready to make beautiful, smooth cuts, you need to wax the table sawÃƒÂ‚Ã‚Â’s table. There are many waxes on the market engineered and designed just for this purpose, but my favorite, and the favorite of many fellow woodworkers is still JohnsonÃƒÂ‚Ã‚Â’s Paste Wax that was meant for use on hardwood floors. It can be difficult to find in some areas, but a single can will last you a couple of years. When you do find JohnsonÃƒÂ‚Ã‚Â’s Paste Wax, stock up on it.