Jointer, Planer, Table Saw Safety
The jointer, planer, and table saw are very important machines. They are necessary to "square up" wood. Squaring up stock (wood) refers to the process of first making one face completely flat using the jointer. Then
the planer is used to make the other face parallel to the first. After that, one edge is made perpendicular (90 degrees) to the faces using the jointer. From there the board is "ripped" to width on the table saw. Keeping the face against the machines table and the jointed edge against the fence will ensure the edge being cut will be parallel to the jointed edge, therefore perpendicular to both faces. The last step is to cut the ends off using the miter saw. This will ensure that the ends are perpendicular to the faces and edges. At this point the board is considered "square". To be clear, this does not mean that the board has the same length as it does width. Just that all edges are 90 degrees and that the faces are parallel to each other, the edges are parallel to each other, and the ends are parallel to each other.
JOINTER
The purpose of the jointer is to flatten and square faces or edges of a board. Before using the jointer you should always check boards for foreign objects and defects. Next look down the edge of the board. Most likely it is not perfectly straight. If the board is warped, always joint the convex side of the board. Check over the machine to make sure everything looks correct before starting the machine. Make sure the safety guard is in place and working properly. When running the wood through the jointer, the wood is always run from the infeed table to the outfeed table. When doing so, the wood must be held tight against the fence as well as the table, so the board will be square. Typically the jointer is used to remove 1/8" of material or less for each
pass. In class we usually set the jointer to remove 1/16" per pass when edge jointing and 1/32" - 1/64" per pass when face jointing. Hands must be kept on top of the wood and away from the cutting area. Never push the wood through from the back of a board. This could easily result in cutting off a portion of your fingers. The jointer has a "cutterhead" with three blades in it that do the cutting. The outfeed table is aligned with the highest point the blades reach in the cutterhead. The infeed table is set lower than the outfeed table. The distance determines the depth of cut being made. The presentation below shows more information about the three machines.
Planer
The purpose of the planer is to remove thickness from wood. Before using the planer you should always check boards for foreign objects and defects. Unlike the jointer, the planer will not flatten a board. It will make a board smooth, but not necessarily flat. Often your teachers in tech classes at school may buy "rough cut" lumber. This is a more economical choice. This wood will need to be planed before use in class projects. It may be 1 inch thick for example and you need wood that is 3/4 inch thick. The wood will be put through the planer multiple times to achieve the desired thickness. Typically only about 1/16 inch or less will be removed at a time. Each time the board is put through it will be flipped to alternate the face being cut. The planer will feed the wood through the machine on its own, however, it is important to keep the wood level with the infeed and outfeed tables. "Snipe" can occur at the end of a board if the wood drops below the level of the outfeed table after running through the machine.
Table Saw
The table saw is a very versatile tool. It can be used to rip (cut with the grain), crosscut (cut across the grain), and make mitered (angled) cuts. The saw has a circular blade used to cut material. Specialty blades can be used to make different types of cuts (like dado and rabbet cuts). The saw has a fence that is used to guide material along when ripping wood. There is a miter gauge that is used to make miter and crosscuts. An experienced operator can use this saw for many different operations. In class the table saw will be used to prepare lumber for class projects; however, students will not be using this machine in middle school.
For safety reasons, when setting up the saw the blade should only be raised to no greater than 1/4" above the wood. One major concern on this saw is "kickback". Many tools can cause kickback, but the table saw is one of the more notorious machines for this occurrence. Newer saws have safety guards that have features designed to help prevent kickback. The safety guard shown in the picture above has shields to help keep hands and fingers out of the cutting area, a splitter to help prevent pinching, which will cause kickback, and anti-kickback fingers that dig into the wood if it starts to move backwards toward the operator. The safety guard should always be in place when using the table saw. The only time it is to be removed is for making dado and rabbet cuts, which do not go through the entire thickness of the wood.
