Introduction: Upgrading Your 6 Inch Jointer With a Sprial Cutterhead

By
About: Retired Electronic Design Engineer. Member of The MakerBarn.

We recently upgraded the jointer at our makerspace The MakerBarn. This is how we did it. the device next to the power switch is an RFID sytem (MACS) we developed to control access to machines.

The six inch jointers sold by GeeTech, Sunhill, Jet, Powermatic, General, and several others, may be easily upgraded to a spiral cutterhead. These cutterheads use precisely ground carbide inserts, rather than the straight steel knifes used in older heads. The inserts are arraigned in several spirals around the cutterhead. Rather than making three wide cuts on each revolution of the cutterhead, the spiral cutterhead makes 34 small cuts. This continuous cutting action makes a much smoother cut with a significant reduction in noise. If an insert gets chipped or dull, it can be rotated 90 degrees to expose a new cutting edge. Since the inserts are much harder than the steel knives, each cutting edge lasts about 4 times longer than high-speed steel knives.

The spiral cutterhead used in this Instructable is the Grizzly H7653. The current cost of the cutterhead is about $330. Check Grizzly's website to see if this cutterhead will fit your machine. Two important measurements are the diameter of the bearing mounts and the distance between the two mounting bolt holes. The bearing mounts on the H7653 are 63mm in diameter and the spacing between the centers of the two bolt holes is 180mm. The H7653 comes complete with bearings, mounts, and even the pulley.

Step 1: Remove the Power Source

Be sure to remove any source of power. Don't put your trust in the machine's power switch. Clean the jointer thoroughly, removing all chips and dust.

Step 2: Getting Started

This is the "before" photo. Remove the guard and place it to the side.

Step 3: Remove the Fence Assembly

The fence is easily removed by simply un-screwing the lock-down screw. There is a special nut on the bottom, be sure to hold onto the nut while removing the screw. The nut has a flange that prevents it from turning. Make note of the position of the flange. Later, it should be reassembled in same way it came off. If put on backwards, it may restrict adjustment range of the fence.

Step 4: Fence Is Removed

The fence assembly is removed and set aside. At this point there are two choices. On some machines the tables can be lowered to the point where the gap between the two tables was large enough to lift the old cutterhead straight up. On my machine, I elected to remove the fence support and slide the cutterhead out of the machine. I still had to lower the tables, but not as far.

Step 5: Remove Cover Panels

Remove the motor cover and the belt guard. if you have a dust collector, remove the dust collection shroud so the it is possible to reach up though the dust chute.

Step 6: Remove the Fence Support

If the tables will drop far enough. this step is not necessary. If not, remove the two bolt securing the table support to the outfeed table so that the old head can be slide out through the back of the machine.

Step 7: Remove the Belt and Loosen the Cutterhead

The belt should be easy to remove. Twist the belt 180 degrees then roll it over the pulley. It should roll off the pulley without having to loosen the motor mounts.

Using an open-end wrench loosen the two bolts holding cutterhead.

Step 8: Remove the Old Cutterhead

If you were able to lower the tables enough to lift the cutterhead staright up, then go ahead and lift the assembly out. Otherwise slide the assembly out through the back side of the machine. Sometimes there may be small shims under the bearing support, Be sure to note where the shims where placed and save the shims for reassembly.

Step 9: The New Cutterhead

The H7653 comes complete with extra inserts and a special wrench for rotating or replacing inserts. Carefully remove the new cutterhead from the box. The inserts are VERY sharp, so watch those fingers.

I wrapped the cutterhead with tape to prevent damage inserts or fingers while installing the cutterhead.

Check one of the bolts that were used to hold the old cutterhead. If the bolt fits the threads in the new cutterhead, use the bolts to secure the new cutterhead. If the bolt does not fit (they may be inch size threads) use the studs provided in the H7653 kit. Using the studs does require dropping the tables low enough to lower the cutterhead in vertically, and it is a be more difficult having to use the nuts to secure the cutterhead, but it is a good workaround if the original bolts cannot be used. The alternative is to use the old bearing blocks, which means bearing and pulley would have to be pulled and pressed.

Step 10: Install the New Cutterhead

Lower in, or slide the new cutterhead in place. Tighten the bolts, or the nuts it you had to use the studs. Remove the tape from the cutterhead. The head should spin freely.

Step 11: Align the Outfeed Table

There are many ways to do this, but the simplest way is to use a good straight piece of wood as a straightedge. I don't like using steel straight edges around the carbide inserts, I don't want to risk chipping an insert.

Place the straight edge on the outfeed table and raise the table until the cutter just barely grabs the straightedge. The inserts should touch the staightedge, but not bite into it.

Check both sides of the table. The cutterhead and table should be parallel. If not, you may have to place small shims under one side of the bearing blocks. Paper can be used as shim material.

Lock the outfeed table.

Raise the infeed table so that it is at the same level as the outfeed table. Use the straightedge to verify.

When you are happy with the table positions, replace the drive belt by rolling it over the pulleys.

Step 12: Replace and Align the Fence Support

If you had to remove the fence support, now is the time to replace it. Install and lightly tighten the two bolts. I aligned my support by installing it a bit high. I then used a piece of HDPE (wood would do) as a straightedge to set the height of the support. I used a couple pieces of paper under the straightedge so that the support would be slightly above the outfeed table. This prevents the fence from dragging on the table and insures fee movement of the fence when tilting.

Step 13: Job Complete

Reinstall the belt and motor covers. Also, if you have dust collection, the collection shroud.

Run a test board and be amazed at how nice the results are. No more struggling with setting blade height, that's history.

Step 14: Make a Dust Chute

Although we have a dust collection system in The MakerBarn, we have never connected it to the jointer. Instead I made a small dust chute from sheet metal. The plastic tub does a great job of collecting chips. With the new cutterhead, the chips are much smaller and flow out of the machine like water.