The Great Grade Resaw Reward:
The Grade Resaw is a piece of equipment that is perfectly fitted to the forest owner cooperative. It is efficient, safe, simple, quiet, and did I mention efficient? This is the third station in the log processing system.
First, the log must be cleaned by a debarker to remove the dirt from the harvesting operation. Merchantable bark mulch or fuel is produced.
Second, the log is opened on a band head saw, taking a cut off of the top of the log. This is the critical stage. The head sawyer must decide the best position of the sawing faces that are used in the rest of the sawmilling operation. Great skill and experience is needed at this step. Unfortunately, a head saw only is cutting about half of the time. Our goal is to have the head sawyer start the process, then pass the less skilled operations on to a more efficient station.
Guided by a laser line, the head saw removes at least the slab from each side of a log, producing a flat side with at least a four inch wide flat face. The cut is made exactly parallel to the bark, to produce the highest quality lumber. Each face of the log is cut in this manner, leaving all the log's taper in the resulting cant. (A cant is a log with at least two sides cut off). If the cant would be larger than 16 inches at the widest end, additional boards are removed from each face in the opening operation, to produce a final tapered cant that is smaller than the 16-inch requirement. As soon as there is a flat surface on each face and the 16-inch size is reached, the cant is removed from the head saw, and sent forward.
Third, the cant moves to the grade resaw. The operator flips the cant around to view all four faces. The best face is placed down, and the cant is directed into the resaw. Since the board is removed from the bottom of the cant with each pass through the resaw, the taper remains in the cant, producing the best quality lumber possible.
As this cant is sawn, another cant is examined, positioned, and placed directly behind the one being sawn. A resaw continually feeds cants through a stationary band saw, with nearly 100% efficiency. Six to ten cants are being processed on the resaw at one time using a "run around system". The operator uses a state of the art 'joystick' control and computerized set works to control the entire process. The lumber is also cut more accurately on the resaw than the band head saw could produce. The simplicity and efficiency of this machine must be seen to comprehend. The heavy cants are never touched by human workers. One concern here in Wisconsin, is that many of the mechanical operations are performed with compressed air systems. During the winter, cold temperatures can cause freeze ups due to condensation. Buildings should be planned to accommodate this aspect of the operation.
Quartersawn lumber has special market value, especially for white oak. The grade resaw is the perfect machine to optimize the production of quartersawn lumber.
Fourth, the lumber flows from the resaw, through an edger saw for those boards needing ripping to improve grade. All lumber then flows to the stickering station for stacking. Once the cant no longer benefits from grade sawing, a multi head band resaw could finish the sawing process more quickly.
This system is the most efficient use of modern technology, and is forest owner friendly.