Troubleshooting Cutterhead Problems for WoodworkingYour new set of cope and pattern cutters has arrived. After running test cuts on the shaper, the wood pieces do not have a snug fit, and in fact may not even stay together.

Most problems with fit are due to a misaligned shaper spindle. To determine:

Check the alignment of the spindle

• Remove the fence and cutter.

• Raise the spindle to its highest position and clamp a 12-18-inch steel straight edge between the spindle collars.

• Lower the spindle until the straight edge almost touches the tabletop.

• Rotate the spindle by hand, observing the gap between the tabletop and the straight edge. If this gap is not uniform, shim the spindle cartridge or table to correct.

• Another quick way to check spindle alignment is to take the center groover from the pattern side and run a test cut in a piece of wood. Take a pair of calipers and measure the cut. If the kerf measures 0.252 inch, and the cut is greater than 0.252 inch there is spindle runout, since a groover can only cut a groove greater than its kerf if it is not cutting perpendicular to the wood.

Check the tongue & groove on a test sample

• Measure the tongue and groove with calipers. The tongue should equal 0.250 inch and the groove should equal 0.252 inch.

• If both sides are off by the same amount, it is a shaper issue. If one side is correct and one side off, it is a cutter problem.

Note: If your set has eased edges, you must nest the pattern center groover in the gullet of the cutters above and below. Failure to do so will cause the carbide of the center groover to hit the body of the other cutters and may result in the center groover bending when the set is tightened on the spindle.

Source: Freeborn Tool Co. For information visit or call (800) 523-8988

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