Here is how I set Jointer Blades:
1. Check that the Outfeed and Infeed tables are flat and Coplanar.
a. Lay a straight edge across the 2 tables. Raise/lower/adjust the tables until they are even with the straight edge along the tables entire length.
b. Odd Observation: Often articles and woodworkers refer to this as squaring the tables. The word here seems odd to me. Square is a term of 90 degree angle or to be perpendicular. The table tops cannot be perpendicular they must be flat in the same plane, that is coplanar.
2. Align the blade slot on the shaft to top-dead-center (TDC), perfection is not required. Don't frustrate yourself!
a. If you have a dial indicator use it on the Cutter Head Assembly (blade holder) to find TDC.
b. If you don't have a dial indicator, do your best to eye ball it into TDC. Don't worry there is a technique later that will find it for you.
c. Use a fine tip permanent marker to record TDC. Scribe a line on the Bearing Housing. Thus the next time you can use this line to find TDC.
3. a. Insert blades, tighten taught. Line up a blade to TDC, then place 2 long magnets on the outfeed table extending just over the blades.
b. One magnet at each end to make the blade coplanar to the outfeed table and even with it. If the blade rises out of its slot, lower the outfeed.
c. I have 2 magnets with handles that are 1/2" x 4" long. You can also use the Grip-Tite Magnet Feather boards. As well, you can purchase a jointer magnet set (it is 2 long magnets with 2 rods connecting them together, the rods serve no purpose for alignment - they are a convience to make it a single assembly jig).
d. The magnet will pull the blade upto the same plane as the outfeed table, you should hear it click. If not loosen the locking nuts a tad. Not too loose, so it doesn't slam up against the magnet and ding the blade!
e. Here is a tip that helps me control tightening the lock nuts and feel assured (in step 4 below) that I am tightening the nuts while maintaining the blade at TDC. Lower the infeed table, with the blade at TDC, insert the wrench onto the lock nut, now raise the infeed table until it touches the wrench. This will help you hold the cutter head steady while tightening each nut.
4. Tighten the locking nuts and repeat on all blades.
5. Make a test cut.
a. Use a board as wide as your table and 16" or so long.
b. Be sure to use a push block.
c. Draw a pencil line down the middle of the edge that is to be jointed. Then joint it.
d. The pencil mark should be gone. If there is pencil mark left at the infeed end of the board, then
the plane of the outfeed table is higher than the blade plane. Lower the outfeed table.
e. If pencil mark is at both ends, then the board is convex, thus it is rocking. Try a few passes while trying to joint the center of the board.
c. If it snipes the end, the outfeed is too low. As the back end falls to the outfeed table the high blade takes a bite.
d. If no snipe then lower the outfeed table until it does.
e. Cross-cut off the sniped end after each test cut.
f. Now find top-dead-center: Raise the outfeed in 1/32" increments until it stops sniping. Then lower it by 1/64", if it snipes raise it back up, if it doesn't your done, unless you really want to try for 1/128".
6. Readjust height of infeed
a. Set a straight edge across the outfeed table and raise the infeed table upto the straight edge.
b. Or use a dial indicator.
b. Adjust the jointer's scale pointer to zero.
7. Check for no taper:
a. Write down the measurement of the board's thickness on 4 edges: left & right sides + outfeed & infeed ends.
b. Run it throught the jointer. Measure the thickness on all edges again. Subtract the before and after measurements.
c. If they decreased by the same amount on both sides, then the blade is coplar with the table.
d. If they decreased by the same amount on both ends, then the outfeed is coplar with top-dead-center, the infeed & outfeed tables are coplanar, and your technique is good. If not, check your technique first, followed by re-checking for coplanar, followed by the snipe test.
Keep in mind the outfeed table is the reference edge. When done, you desire that the jointed face rests perfectly flat on the outfeed table.
1. This example: jointing wide face down on the table, using 2 push pads with handles.
2. Place 1 push pad a few inches from the front edge and the other mid table to near the end of the infeed table.
3. As the 1st push pad passes onto the outfeed table adjust your weight on to it, being careful to not push the back end of the board down onto the infeed table. Infact if it raises off the infeed table it is ok. You want to keep the freshly cut reference face on the outfeed table. When you have a foot or so on the outfeed, move the 2nd push pad to the outfeed, just behind the cutters.
4. Alternate pushing with 1 push pad, while you slide the other back toward the cutter direction, maintaining pressure down on the outfeed and as close to the cutters as safely possible. Both pads are pushing down and out when you are not alternatingly adjusting them back into position.
5. When using a push pad along with a push block (square end resting over end of board), push with the push block, not down. When the push pad is on the outfeed, occasionally slide it backwards while maintaining downward pressure.
6. What I am saying here is the most important pressure to maintain is on the outfeed table, just beyond the cutters. Little or no pressure is required on the infeed.
7. Use light to medium pressure on the outfeed. Too much pressure on the outfeed can create any number of problems: end to end taper, side to side taper, side to opposite side taper (warp), rocking (bow), etc.
Squaring and flattening a work piece:
1. Lay the board flat and joint it. The goal is to create a reference for which the other 3 faces will become square to each other. Just take off 1/32" (no more than 1/16"), you can have a board that is too thin very quickly. Don't be concerned if there are a few patches of rough wood in the middle, you can plane it out later, just assure that all four outer surfaces are jointed.
Observation: Some say run it through a thickness planer first. Depending on the wavyness and parallelism of the opposite sides (and other factors like twist and cupping) this may work, but not always; most likely, seldom.
2. Rest the jointed face against the fence with the edge resting on both tables.
a. Setup a feather board on each table to hold the jointed face tight against the fence.
b. You can forgo the feather boards, but you chance tilting the board (even ever so lightly) while you' are pushing it along. You may get a taper across the edge completely or intermittently.
c. The magnet feature boards are perfect for this setup.
d. Joint the edge.
3. Run the board through the thickness planer, reference face down on the platten, to make the opposite face parallel to the reference face.
4. Rest the planed face against the jointer fence, adjust feature boards, and joint the last edge.
All 4 faces are now "perfectly square", in fact the corners feal sharp.
I get good results with any of these sequences. Grain direction will dictate which sequence to use.
a. Joint face (reference), joint edge, plane opposite face, joint opposite edge (opposite face is reference).
b. Joint face (reference), joint edge, joint opposite edge, plane opposite face.
c. Joint edge (reference), joint face, plane opposite face (face is reference), joint opposite edge (opposite face is reference).
d. Joint face (reference), joint edge, plane opposite face, plane opposite edge (opposite edge is reference). Do this on 6/4 or thicker lumber, or carpet tape the lumber to a 2x4 scrap.
Grain Direction while jointing:
1. Before jointing each face, read the grain. Run it through so the cutter cuts into (with) the direction of the grain. That is, the points of the rays are pointing to the rear of the infeed table.
outfeed table on this side: [ ] | [>>>>] <---- push direction (grain direction: >>>>)
2. Often the rays are multi-directional, first try the most directional as the grain direction.
3. Even if it looks very smooth, run your hand over it. If you feel tiny burrs, try the other direction (if you can spare the thickness, otherwise sand it out).
4. An excellent technique for multi-directional grain is to dampen it before jointing (also a great technique for planning). This is a fantastic technique for Maple. Just let it soak in to the depth that you will be taking off.