A jointer is primarily a woodworking machine used for producing flat edges on boards before joining them edge-to-edge to produce wider boards. In the U.K and Australia, they are referred to as planers or surface planers. The jointer operates at the narrow edge of boards, and it has a table arrangement consisting of two levels referred to as infeed and outfeed. The work piece is fed into the machine from the infeed table. The outfeed table serves as the height reference table on which the work piece is floated as it leaves the machine cutting head. A fence is normally set perpendicular to the table although some models may allow the fence to be adjusted to various angles.
Joinery Carpentry
A cutter head, typically powered by an electric motor is inserted between the tables. Older machines are driven by belts from line shafts. The cutter head is equipped with two or more knives which are arranged radially in the cylindrical cutter head. Older jointer models use square instead of cylindrical cutter heads. Square cutter heads leave a wider open region below the level of the blade edge. This increases the risk of hands being pulled in, causing injury. The cutting blades are adjusted to match the height of the outfeed table.
Putting the
jointer to use
Generally the width of cut for home workshop jointers is 4-6 inches. Hold the board to be jointed with its face against the fence and the edge to be jointed should rest on the infeed table. While maintaining a constant feed and downward pressure, the work piece to be planed flat is placed on the infeed table and carefully passed over the cutter head to the outfeed table. The infeed and the outfeed tables can be adjusted independent of each other so that either can be raised or lowered in relation to the cutter head. Typically the infeed table is adjusted so that it is lower than the outfeed table to give the depth of cut.
The knives in the revolving cutter will remove some amount of material from the work piece. This will result in and edge that is flat along its length. If you wish to flatten the face of a board, focus on producing a flat surface on the board’s face without using the fence. This is usually the case before edge jointing so that the board can have a flat reference face.
Other good
uses of the jointer
One great
use you can put your jointer to is straightening the curved edge of a bowed
board. To straighten a piece of bowed timber you need to swing the guard out of
the way temporarily. Power-on the machine and gradually lower the timber on to
the machine table with the concave side down.
Successive
cuts are made from each end. This is repeated as required with successive cuts
longer each time the board is turned end to end. The guard is replaced when the
timber is almost straight and the work piece can be taken to a table saw to
make a cut for a new parallel edge.
If you have
a twisted material, you can treat it in the same way. Place the timber on the
machine bed and rock it gently from side to side taking off some material from
each end every time depending on the extent of twist. Another use you can put
your jointer to is to make rabbets. In some countries, rabbets are also known
as rebates. Just set the fence to the width of the rabbet and set the infeed
table to depth required.
Final
thoughts
A jointer is
a valuable addition to your woodwork shop. You can use it to produce a flat
surface along the length of a board. You can also use it to straighten the
curved edge of a bowed board or twisted material. If you need to create a board
of even thickness along its length, you will need a thickness planer for that.
Thickness planers and jointers are sometimes combined into one machine. The
machine is then referred to as a planer-thicknesser.
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