How to Replace the Cutter Head of a Jointer Planer How to Replace the Cutter Head of a Jointer Planer

What You'll Need
New spare jointer knives
Paper towels
Phillips screwdriver
Utility knife
Wrench, open-ended (1/4 inch)
Adjustable clamp
Blade alignment jig
Small paintbrush
Steel ruler
Steel straight-edge (Machinists)
Steel scribe
Solvent, water-based

The jointer planer head contain the blades which are used to cut through wood. With constant use, the blades on the cutter and the cutter head itself will show signs of wear and tear so you will need to replace these parts to keep your jointer planer in condition. To replace the cutter head and the knives on a jointer planer, here is what you should do.

Step 1 – Get the Work Area and Jointer Ready

Unplug the jointer-planer or pull down circuit breaker if it is applied to the input power line. Bring the materials to a working table. This is extremely important so as not to trigger the jointer if something goes wrong. Take out the screw using screw driver from the blade guard found on the upper pulley. Pull-out the blade guard sideways from the jointer.

Step 2 – Check & Remove the Replaceable Part

Roll the drive pulley securing one blade in between the input and output feeder. Use adjustable clamp to lock drive belt to lower pulley. Unlock knife locking bolts with wrench. Pull out knife along with locking bar; do the same with the remaining knives. Remove clamp.

Dip the bolts and locking bars into the solvent to remove wood debris. Take out dirt residues from knife slots; brush off with solvent. Wipe with paper towel to dry.

Step 3 – Install New Jointer Knives

Place the new knives into the slots and re-install the locking bars. Tighten partially the bolts to make room for later knife adjustments. Put straight-edge on top of output feeder; rest flat side on jointer fence. Adjust the input table up to straight-edge to get same height. Take out straight-edge and replace with steel ruler. Locate top dead center of one blade by rotating head pulley and checking the gap between ruler and the cutting edge. Mark the point coinciding on the fence to be used as future reference.

Step 4 – Align the Position of Knives

Lower down the input feed. Place the alignment jig at the output side while securing the left portion of the jig over the fence. Align the marked guide of jig to the top dead center marker on the fence. Draw another line on the fence indicating the end guide on the other side of the jig. Such reference will quicken future knife replacements.

Loosen the locking bar of first knife. Roll the upper pulley until the edge of first knife coincides to the dead center mark on the fence. Let the front bar on blade alignment jig snap the knife into alignment with the output table. Adjust to tight each locking bolt taking careful steps not to change the alignment of blades. Repeat this activity to do the same with other two knives.

Step 5 – Finishing Up

Re-install back the blade guard and fix with screws. Check and adjust tension of drive belt where applicable. Put away your tools, the used blades and left over materials in a safe place. Clear the working area and get the jointer planer ready for use.  

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