Jointers flatten out the warped parts of boards after they've been milled, dryed or just sitting in your basement. They are also used for cutting chamfers, rabbets, and tapers. The jointer automatically straightens out an edge and a side of your wood, known as surfacing boards, so that several planks can be glued next to each other without gaps or bends in the wood.
Woodworking.com has an interesting article on the values of a jointer. Consider investing more money in a jointer with the money that you'll save by buying unfinished wood. You'll get more autonomy with your projects and more satisfaction as well.
As with all machines, the quality is generally directly proportional with the cost.
* Jointers are sized by the '''length of knives''', or '''cutterhead width''', which determines the maximum width of the board you can surface.
** Six to eight inches is good for home use, but jointers can be as narrow as four inches or as wide as 24 inches.
** Benchtop models are usually no more than six inches, so if you are serious about your woodworking you'll want a heavy, sturdy model 8 inches or more. There are also 6 inch floor-standing jointers.
** There is a big price jump between tabletop and floor-standing models.
** Generally speaking, the bigger the machine, the bigger the pieces of wood it can handle. Price grows accordingly as well.
* Longer '''infeed''' and '''outfeed''' tables will help better support your work and let you flatten longer boards. The rule of thumb is that you can support double the length of the jointer in wood. For example, a six100 inches.
** Jointer tables should be exactly parallel to each other.
** An eight$700), unless you're working with smaller scales.
* '''Alignment''' is essential in your boards and blades. If your planes are not properly positioned (a perfect 90 degrees) then all of your products will be skewed. A quality jointer will take care of proper alignment.
* '''Table and Blade Construction''' determine how long your jointer will last and what kind of wood you can use. The stronger the table and blades you have (like cast iron as opposed to aluminum) the more flexibility you'll have with wood choice.
* '''Table Adjustment''' should suit your needs: either speed or precise control. For quick adjustments choose a lever style, and for accuracy, a wheel style. Choose a front-mounted wheel instead of the less convenient under the table style.
* '''Motor Power''' abides by general moter power rules. The stronger the motor, the stronger the jointer. Typical range is from 3/48" model.
** Look for enclosed and fan-cooled (TEFC) models for superior life and cleanliness.
* '''Dust Collectors''' or dust ports are handy for keeping sawdust out of the air and your lungs.
* '''Fences''' guide the board through the cutterhead. They should be stable and rugged, but easy to adjust. They should also have several stops (90, 45 and 135 degrees).
* '''Floor vs. Benchtop Model''' debates usually end with the floor model winning. floor model.