Be sure the tables need to be leveled…
I was having trouble getting my jointer to cut a straight edge, the center would be cupped in towards the middle, causing gaps between boards. No matter what I tried I could not get a perfectly straight edge. It turned out this was due to the outfeed table not being parallel to the infeed table. Before adjusting your own equipment make sure that the problem is not technique. That said… Here are the steps I took to level the tables on my own jointer.
As you can see from the photos, the outfeed table is lower at the end than it is next to the cutter head. The actual gap turned out to be approximately 0.020″ at the end (.5mm). Not a lot but enough to cause gaps between long boards.
- Empty aluminum can or steel shim stock
- Tin snips or heavy duty scissors to cut the can into strips
- A good long level or straight edge. Ideally a foot or so longer than your outfeed table although a shorter one will also work.
- Hex key to loosen the gib screws
- A helper (optional but nice)
- Set the depth of cut to zero.
- Rotate the cutterhead so that the blades are out of the way. If you have a spiral cutterhead you can raise the tables to be a little higher than the cutters.
- Lower the outfeed table so it is slightly lower than the infeed table, the exact amount is not important.
- Clamp your level to the infeed table as shown below. The majority of the length of the level should be on the outfeed table. I used a 48″ level so about 12″ was in contact with the infeed table.
- Raise the outfeed table until it just barely touches the level (see arrow above). At this point you should be able to determine if the tables are out of parallel. If the gap between the outfeed table and your level gets larger as you move along the length of the level you will need to shim the outfeed table.
- Loosen the outfeed table gib screws (shown by arrows below).
- Cut the can into strips about 1/2″ x 1″ (or 12x25mm for the other 95% of you on the metric system) and stick them between the outfeed table and base as shown below. I did this the hard way and lifted the table by getting underneath it and pushing up, you will probably want to find a helper.
- Repeat the step above until the tables are level and retighten the gib screws. You want the outfeed table to move but not as easily as the infeed table. You should rarely need to move it once set.
- Adjust the outfeed table height to be in line with the top of the path the cutters make.