8 Table Saw
8.1 Table Saw Overview
The table saw is one of the most versatile, accurate, and important tools in the shop. It is one of the most heavily used machines, and perhaps as a result, it has a reputation for the most accidents. As with the other machine tools, table saw accidents will be avoided with proper setup and training.
Ripping and cross-cutting are the two basic operations performed on the saw. Ripping is cutting with the grain of a board or along the long dimension of a sheet material and uses the rip fence. Cross-cutting is cutting across the grain or along the shorter dimension of a sheet material. Cross-cutting uses the miter gauge or cross-cut sled.
The Sawstop mechanism senses finger contact on the blade and immediately stops the blade using a brake cartridge to prevent serious injury. Wet wood and metallic objects (staples, nails, etc.) can also trigger the brake and must never be cut on the saw.
Sawstop’s safety cartridge does not prevent kickback. Kickback, discussed in 1.4, is when the saw blade grabs or binds the wood and throws it back towards the operator with immense force. It can cause serious accidents. Table saw kickback is caused by improper usage—correct precautions and careful use will prevent it.
Handwheels on the cabinet are used to raise and lower the circular saw blade in reference to the large cast iron table, and tilt the blade over from 90° vertical. Blades are easily changed by accessing the arbor nut, underneath the removable throat plate. The rip fence runs along the front rail and is locked into place in reference to a marked scale along the front rail. The miter gauge and shop-built sleds run in the tee-slots along either side of the blade.
Riving knives or splitters are thin, hook-shaped pieces of steel located directly behind the blade. They are incredibly effective in preventing kickback. Splitters prevent wood from coming in contact with the rear of the blade. At the rear of the blade, the rotational force can lift the workpiece off the table. Splitters also prevent internal board tensions from closing the kerf behind the blade.
Over-blade guards cover the blade and have attached pawls to prevent kickback. Over-blade guards hinder some table saw operations, i.e., cross-cut sleds or narrow ripping cuts. They are often removed to complete these cuts. Whenever possible, a splitter should be installed on the machine. In both operations above that an over-blade guard may prevent, a splitter can be used.
There are many different styles of blades available for table saws. Four of the most common types are ripping blades, crosscut blades, combination blades, and dado blades. Choosing the correct blade for the operation is important for safety concerns as well as the quality of the cut.
Ripping blades are used for cutting parallel with the grain and removing long fibers of wood. Ripping blades have fewer teeth and large gullets. Gullets help clear the long fibers of wood created from a ripping operation. If chips and sawdust are not cleared from a cut, blades can bind and/or overheat leading to premature wear and potential kickback. One of the most important factors in avoiding kickback during ripping is to use a sharp ripping blade.
Cross-cut blades are used for cross-cutting solid lumber and processing sheet goods like plywood. They have a high number of teeth per blade and are dangerous if used for ripping solid wood.
Combination blades are designed with features for both ripping and cross-cutting. As a hybrid, however, they are a compromise. They can perform suitably well for cross-cutting solid wood and plywood; however, if a dedicated ripping blade is available, it should always be the first choice for a ripping operation.
Dado blades are created from a stack of separate cutters, significantly increasing the kerf of a table saw. Dado blades are used to cut joinery, dados, grooves, and rabbets. Chipper blades are sandwiched between larger inner and outer plates. Different widths can be achieved by swapping chippers of different thicknesses and shims in between the plates. Sawstop dado stacks are smaller in diameter than ripping, cross-cut, or combination blades, and require changing the brake cartridge at the same time.
Table saw blades, especially dado stacks, must be changed very carefully. It is possible to install them improperly, creating dangerous situations. Selecting and installing table saw blades is an essential skill to learn to work safely and create quality work in the woodshop. Like all machine tool operations, blade changes should be completed under supervision until a beginner learns how to complete them independently.
8.2 Table Saw Operation
Plan your cut carefully before starting. Is the correct blade installed? Is your material milled/surfaced appropriately? Is there a push stick handy? Is the work surface tidy and organized? Is the blade set at the proper angle? Are the correct jigs or fences installed? Have you completed all necessary layout?
If you need someone to assist you at the saw cutting a large piece of material, always discuss and practice the plan before cutting. Lower the blade completely and complete a dry run together. An assistant catches or holds, never pushes or pulls. The second set of hands is there to guide the material only; the operator maintains full control of the stock.
You must never back out of a table saw cut. Moving material with the blade rather than against will result in kickback. If a cut goes awry: Maintain complete control of the stock with both hands and use your knee to operate the slap switch to turn the saw off. Keep a firm grip on the material until the blade comes to a complete stop, then pull the stock out and assess what in the operation needs to change.
The Sawstop has a complex circuit as part of the finger-sensing safety device. A toggle switch at the control box needs to be turned on first, and then the red paddle switch is used to start and stop the blade. After the toggle switch is turned on, the system takes a few seconds to initialize. Once the status light is a steady green, the paddle switch is operational. A red and green light on the box flash in combination for error codes. Codes can be read with a table on the side of the box.
Ripping
- Make sure the ripping blade and riving knife or blade guard are installed.
- Adjust the height of the blade to 3 full teeth above the stock. This ensures a gullet is completely free to clear sawdust appropriately and typically means the blade is ¼” – ½” above the material.
- Slide the rip fence to the correct measurement along the front rail and lock it into place. The fence should be on the right-hand side of the blade.
- Stand with the side of your body to the saw.
- Make sure the blade is not in contact with the workpiece and turn the blade on.
- Complete the cut, use your left hand to push the material into the fence, and your right hand or push stick to push the material forward. Use steady and firm downward and forward pressure.
- Push the workpiece completely past the spinning blade before turning the blade off.
- Wait for the blade to stop spinning, and walk around to grab the workpiece and scrap cut-off.
Tips for ripping at the table saw:
- Do not fixate on the blade, keep your attention and sight moving across the entire operation. Pay attention to the board edge running along the fence as well as the blade.
- Stand right up directly on the saw. It can be an intimidating machine to use, but control is critical. You will be in a better position to control the workpiece the closer your body is to the table. Push sticks can help extend your reach, and its okay to lean against the saw as your finish a cut and push the board past the blade.
- If you are unsure of the operation, practice a dry run to build confidence. Lower the blade completely under the table surface so it will not cut the material. Adjust the fence, turn on the saw, and complete the cut exactly as you’ve planned.
Cross-cutting
- Make sure the combination or crosscut blade and riving knife are installed.
- Push the ripping fence to the far side of the table.
- Adjust the height of the blade to 3 full teeth above the stock.
- Hold your stock tight against the sled or miter gauge backstop.
- It is safest to hold the board on one side of the cut only. Pressure on both sides can bind the blade and result in kickback or burnt cut.
- Be careful of small scrap pieces typically created during cross-cutting operations. Do not reach close to the spinning blade to retrieve them.
- Turn the blade on and complete the cut.
- Pull the miter gauge or sled completely back from the blade and reach down to turn the saw off.
- Keep your hands clear until the blade stops spinning completely.
ALWAYS control stock with the rip fence, miter gauge, or a sled. NEVER cut freehand.
ALWAYS stand to one side of the blade to avoid kickback.
DO maintain the 6” margin of safety, use a push stick when necessary.
ALWAYS push the stock firmly against the fence when ripping.
DO check material for knots, checks, splits, or nails, staples, etc.
DO set the push stick in place before starting the cut.
DO return the blade to 90° after using the saw and drop the blade below the table.
ALWAYS push the stock completely past the blade while cutting.
ALWAYS use a sharp blade.
DO NOT operate the table saw with someone standing behind you.
NEVER back out of a cut.
NEVER use both the fence and miter gauge at the same time.
NEVER make a beveled cut with the blade tilted towards the ripping fence.
NEVER push stock into the fence past the back side of the blade.
NEVER cut warped wood. Check for straightness using the wing of the table saw and/or the ripping fence before cutting. At a minimum, joint a face and edge before cutting on the table saw.
DO NOT let small scraps accumulate around the blade. NEVER use your hand to push away a scrap while the blade is running.
