Tighten the knife and repeat for each knife to be set. Use Proper Knife Projection. See figure 61 on page 64. K is the knife. H is the head body.
G is the knife gib.
When machining green lumber the distance A should be greater than for dry stock. When the gib G shows excessive wear from contact with the knife it should be replaced. Several types of planers are equipped with portable grinders. Too much knife projection or worn knife gibs, due to excessive projection, frequently causes the knives to break and fly in all directions. Knives with a cutting angle of 20 to 25 can stand more projection beyond the lips of the head than knives with 25 to 30 cutting angle.