Fine-Tuning a Jointer
I recently changed the knives on my 6-in. jointer and set them level with the outfeed table. Now the jointer leaves boards slightly concave in the middle. Do I have to adjust the outfeed table again?
Bill Smith, North Attleboro, MA
Yes. No matter how carefully you install new knives, you can nearly always improve a jointer’s accuracy by fine-tuning the outfeed-table height after the knives are in place.
This fine-tuning is easiest if the outfeed table has a handwheel for height adjustments. It’s almost impossible if the table has a lever for height adjustments.
Begin with the outfeed table a bit low, and edge-joint two boards that are one-half to two-thirds the length of the jointer. You’ll almost surely see a gap when you put the jointed edges together. Raise the outfeed table in small increments and joint the boards after each adjustment. When the edges match perfectly, you’re done.
Photo: David Heim; Drawing: Kelly J. Dunton