So often the woodchipper is blamed by the operators when it blocks up, feeds slowly, or struggles on foliage. The operators become impatient and annoyed, and work the machine harder and harder.
Usually the problem is not with the chipper itself, but the simple fact that the knives are blunt. Dull knives can sometimes be “touched up” without removing them from the chipper. A mill file will often bring back a sharp edge or, the ‘Accusharp’ tool sharpener is great for this purpose. The main point to remember is that only the bevelled edge of the knife can be sharpened, not the face. Once the knives are beyond ‘touching up’ by hand, they must be removed and sharpened by a professional chipper knife grinder at the correct angle.