VENEER CUTTING is done in three ways; first, by saws, which, of course, waste in kerf a very large proportion of the stock, the greater proportion being in the case of those woods which, by reason of their costliness, are made into the finest veneers ; second, by knives which slice the material into sheets as wide as the width of the log ; and third, by knives which turn from the log a ribbon of any desired thickness, as wide as the length of the log, and as long as desired. In the latter case, of course, the natural pattern of the wood, as we under stand the pattern, is lost, although as a matter of fact the pattern left by the ribbon-turn ing machine is as natural as any other, the tree to us, in its natural state, neither the one class nor the other of grain pattern.
In veneer-turning machines, the log, say, in sections -IS in. long, is held between two live centers, and presented to the action of a slicing knife, the full length of the log, and an automatic feeding attachment brings the knife closer and closer toward the center of rota tion as the stuff is removed ; the distance advanced in one rotation being the thickness of the sheet pared off. In working in common stock, the machines are furnished with scoring knives to cut the stuff to length, or to mark it for bending, as for berry boxes, grape baskets, etc. Sometimes the machine has a roller with knives on its surface, for cutting stuff to width
and shape. In one of the best-known rotary veneer-cutting machines, the rough log is cen tered between chucks and rotated against a knife which is moved forward upon a carriage, fed by screws and a suitable system of gearing. The chuck arbors have two bearings far apart. The knife has a quick-return motion, and can be stopped, advanced, or reversed by moving a lever ; and there is an automatic safety attachment by which the knife stops at any desired point in forward or backward travel. In some machines there is an especially quick advance of the knife to bring it up to the cut. The desired thickness of veneers is secured by a change of feed gear, which varies the rate of rotation of the screws.
The knife is set at an angle to the with its bevel side next to it, thus en the cutting edge to act at the center line or a trifle above it ; and this angle is maintained down to the small est core which can be left.
Vise : sec Pipe-cutting Machinery. Warper : see Cotton-spinning Ma chines.