Modern Woodshop

Changing your jointer knives can be a painful and frustrating experience. A little jig called the Jointer Pal, however, can make your life a lot easier. I bought mine at Grizzly for $26.95.

Here’s a step-by-step pictorial of how to use it. This whole process shouldn’t take you more than 30 minutes. It took me about an hour, but I was photographing every step, so that slowed me down a bit.

Step 1: Unplug the jointer and remove the blade guard

Before you do anything, make sure that your jointer is unplugged. Next, you need to remove the blade guard for easy access to the jointer knives. On my jointer, this means removing a small screw on the bottom of the shaft attached to the guard. Once the screw is removed, you can pull it straight off the jointer.

Step 2: Remove the old knives

Using a wrench, loosen the four locking screws at each knife and remove the knife and locking bar.

If you have a slight set in your belt, it can sometimes be difficult to get the cutter head to remain in position while you are trying to remove the knives. If you run into this problem, putting a small quick clamp on the pulley will hold the cutter head in place.

Step 3: Clean the cutter head and locking bars

Eeeeew. The locking bars and cutter head are pretty nasty. Sawdust, pitch, and grease work their way in over time and make a mess. Soak the locking bars in Simple Green for a couple minutes and all that stuff will wipe right off with a paper towel. Spray some Simple Green on a towel and wipe out the cutter head as best you can.

Here are my clean locking bars, clean cutter head, and new knives.

Step 4: Insert the new knives

Put the new knives into the cutter head and snug them down just enough to hold them in. We’re going to use the jointer pal jig to set the knives to the exact height of the outfeed table.

Step 5: Find and mark Top Dead Center

In order to use the jig, you need to locate Top Dead Center (TDC). This is the top of the arc of the cutterhead. Lay a steel straigtedge across the jointer tables and rotate the cutterhead until the edge of the knife is at it’s highest point. Obviously, this is somewhat subjective, but you should be able to get very close.

Now I know this next part is going to freak some of you out. Just remember that your jointer is a tool, not your dining room table.

Etch a mark on your jointer fence at TDC. I slide my straightedge back until it’s end was lined up at TDC, and then I used a utility knive to etch a heavy permanent line on my fence at that point. You only need to do this once. Now that you have TDC marked, it will be easy to set up your jig every time you want to change out your knives in the future.

Now set the jig on your outfeed table and line up it’s guide mark with your TDC mark. There is a second guide mark at the back of the jig. I recommend that you etch a line at that point onto your fence, as well. With these two lines, you’ll be able to position your jointer pal in the proper position in seconds.

Step 6: Set each knife’s height and lock it down

Now that you have the jointer pal in position on the jointer, loosen the locking screws on the first knife and rotate the cutterhead until the knive edge is at TDC. The powerful magnets on the jointer pal will grab the knive and hold it at the exact height of the outfeed table while you tighten down all of the locking screws. Repeat this step for all three knives.

Now, in my case, I actually needed to raise my outfeed table a bit. I wanted a smidge of room between the jointer pal and the knife so that it had room to pull that knife up to the appropriate height. You may or may not need to do this.

Step 7: Recalibrate your infeed table height (if necessary)

Since I changed the height of my outfeed table, I needed to re-zero the positive stops on my infeed table. I laid a long straightedge along the jointer bed and adjusted the infeed table until it was at the same level as the outfeed table. This is the zero position. I locked the table in position, and reset the positive stop at this point. Check your owners manual for instructions on how to do this; every jointer is a little different. I also needed to zero out the pointer on the scale on my infeed table, as well.

Step 8: Replace the blade guard and do a happy dance

Put your blade guard back on the jointer and adjust the spring tension, as needed. You’re done! Sorry, no pics of me dancing.