Table 2 . --Fingerling production by operating speed and log diameter 



Log diameter : Cutter head R/min 



(inches] : 300 : 350 : 400 



Cubic feet per minute — 



4 5.5 6.5 7.5 



6 12.0 14.0 16.0 



8 21.5 25.0 28.5 



10 34.0 40.0 46.0 



Large Residue 



The Arasmith Manufacturing Company drum chipper was chosen for chipping large 

 residues. A contract resulted in a modified drum chipper with special knives to cut 

 chips 2 1/2 inches long (fig. 5). This chipping process required cutting the residues to 

 the length of the drum and feeding the log axially parallel to the axis of the drum. 

 The primary drawback is having to cut residues to a specified length. The principal 

 advantage is that when chips are cut parallel to the axis of the log, horsepower 

 consumption is not highly sensitive to log diameter. When the knives cut through the 

 diameter of the log, large horsepowers are needed for larger logs because the cutting 

 power increased proportional to the square of the log diameter. The modest horsepower 

 required by the drum chipper will allow use of relatively low-powered units suited to 

 in-the-woods chipping. The manufacturer estimates that a 42-inch-diameter , 60-inch- 

 long drum chipper making 3/8-inch-thick fingerlings can be driven with a 200-hp diesel 

 engine. Its output could be about 50 tons per hour of operation when fully loaded. 



Figure 5 . — Modified drum 

 chipper. 



5 



