3308 Chapter 27 



Two-ply cuttings. — With a laminated, 2-ply furniture cutting, defects on one 

 face would not go through to the other face as they usually do in a conventional 

 cutting (sect. 22-3, subsection LAMINATED LUMBER, page 2568). Losses 

 from defects would be reduced and yields substantially increased (fig. 22-2). 



Squares. — Anderson and Reynolds (1981) developed a computer program to 

 determine the relationship between bolt diameter and yield of squares of various 

 sizes. In developing the computer program they made two assumptions, which, 

 while not true in actual sawing of bolts, clarify the relationship between the 

 number of squares produced and the changes in square and bolt sizes. First, they 

 assumed that the bolts were perfectly clear truncated cones, 4 feet long with a 

 large-end diameter ^/2-inch larger than the small end. Second, they did not 

 consider defects because their main interest was to find how many squares of a 

 specific size could be obtained from a bolt with a given small-end diameter, 

 considering bolt sawing patterns, cant sawing patterns, saw kerf, square size, 

 and bolt diameter. 



They also assumed that a turning square does not need four square comers, 

 particularly if it is used to make a round. Thus, some wane was allowed. The 

 wane was determined by calculating the size of a round that could be made from 

 a given square. They calculated a width for each cant sawed from a bolt. Then 

 they determined the maximum number of turning squares that could be sawed 

 from the cant if some wane was allowed on the outside squares. 



Two techniques for sawing bolts to squares were simulated: the boxed-pith 

 method, in which a center cant containing the pith was sawed from the bolt, and 

 the split-pith method, in which the bolt was sawed down the middle. In both 

 cases, all of the bolts were sawed parallel to the pith. Outside slabs were resawed 

 to cants if they were large enough to yield one or more squares. The simulation 

 of sawing squares from cants was the same for both sawing methods. Squares 

 were sawed from alternate sides of the cant and sawing was parallel to the bark. 

 A tapered waste piece occurred in the inside of the cant. Square sizes were 

 simulated in 0.5-inch increments from 3.0 to 6.0 inches. Saw kerfs were held 

 constant for all runs with a headrig kerf allowance of 0.375 inch, a slab resaw 

 kerf allowance of 0.3125 inch, and an edger kerf allowance of 0.1875 inch. 



Seven different sizes of turning squares ranging from 3 to 6 inches in !/2-inch 

 increments were evaluated. Because the results were consistent throughout, they 

 reported only on the 3- and 6-inch squares sizes since they represent the extremes 

 tested. Data for each individual bolt diameter and square size are available from 

 the Northeastern Forest Experiment Station, Forestry Sciences Laboratory, P.O. 

 Box 152, Princeton, W. Va. 24740. 



Neither sawing method was best for all sizes of squares or for all diameters of 

 bolts. The total number and distribtuion of squares from each sawing method 

 were not identical. However, they were too similar to show overall superiority of 

 one method. Results are summarized as follows: 



