A jointer shaves small amounts of wood from the faces and edges of your work in order to provide you with straight and even surfaces. This allows you to make accurate cuts and measurements. Any errors you make during the jointing stage of your project will be compounded in later stages. To get the results you want from your jointer, you must ensure that its moving parts are perfectly aligned: the knives, the infeed table, the outfeed table and the fence.
Check Table Height
Unplug the jointer. Pull the guard away from the cutter head, then put a clamp between the guard and jointer to keep the guard from moving back into place.
Place a straight edge on the outfeed table and extend it over the cutter head and infeed table. The infeed table should be below the level of the straight edge.
Use the wooden wedge to move one of the knives to its highest point. The knife should just brush the bottom of the straight edge. If it doesn't, turn the outfeed table adjustment handle to raise or lower the table to the correct height.
Move the straight edge along the knife edge to ensure that the knife is level. Check the remaining knives in the same manner.
Align the Tables
Use the infeed table adjustment handle to raise the table to the same height as the outfeed table. Place your straight edge over the two tables to confirm that the tables are level. The straight edge should be flush against both tables.
Adjust one or more of the gib screws at the back of the jointer until the straight edge rests flush against the tables, if the tables are not level. To adjust the screws, use your adjustable wrench to loosen the locknuts, then use your hex wrench to turn the screws. Tighten the locknuts when the tables are level.
If you adjusted the outfeed table level, verify that it is still at the same height as the knives.
Square the Fence
Set the fence in its vertical position. Stand your try square on the outfeed table near the cutter head and butt it against the fence. The try square should be flush against the fence.
Loosen the fence control handle if you need to adjust the fence. Move the fence until it is flush with the try square. Tighten the fence control handle.
Check that the set screw on the fence stop butts against the metal stop. If it doesn't, hold the set screw locknut with your adjustable wrench and turn the set screw with your hex wrench until it touches the metal stop.
Move the tilt indicator to "0." Remove the clamp and close the guard.