,'ii h ; vji-xi 
 
 T* 6 
 
 FOREST PRODUCTS LABORATORY t FOREST SERVICE 
 U. S. DEPARTMENT OF AGRICULTURE 
 
 - 
 
 7 
 
 SMALL SAWMILL IMPROVEMENT 
 
 PRACTICAL POINTERS TO FIELD AGENCIES 
 
 SMALL MILL CONVEY 
 
 A conveyor that carries the sawdust, edgings, and lumber, away from the mill i. 
 labor saver for mills cutting enough at a set to warrant .the- installation costs. 
 The conveyor shown in figure 1 is of the simple-trough type, in which the load is 
 carried by a moving chain with cross bars or lugs^-sp-icd at intervals. It extends 
 from the saw pit straight back to a burner and is readily accessible to headsaw 
 and edger sawdust, to the sawed stock, as it falls away from the headsaw, and to 
 the edgings and edged boards from the tail end of the edger. Lumber is pulled off 
 this conveyor at a point beyond the mill that is sufficiently elevated to permit 
 package piling where the haul-out vehicle can back under the load. If slabs can 
 be utilized, these also may be taken out, cut up, and collected in an elevated bin 
 permitting cheap handling. The cutoff saw would be located along the conveyor 
 (beyond the lumber pull-off deck) and powered by a small power unit separate from 
 that used to run the mill. This feature is not shown in the figure. Provision 
 may also be made to deflect the boards and edgings from the rear of the edger, 
 thus eliminating the need for a tail edgerman. A live roll is required in the 
 rear edger table, along with an inclined platform to carry material by gravity into 
 the trough. This possibility is suggested but not shown in the figure. The con- 
 veyor is inclined so that, starting below the saw, it is slightly below the bed of 
 the rear edger table about 18 feet back of the edger saws, and at the discharge end 
 it is approximately l6 feet above the burner pit. Timbers or ties are taken over 
 dead rolls to the timber dock. 
 
 The conveyor chain should be geared to travel at a rate of speed that will insure 
 the boards being spaced in the conveyor. This will facilitate pulling the lumber 
 off the conveyor chain. For example, when a mill cuts 8 saw lines per minute of 
 l6-foot logs, a speed of 128 feet per minute would be required to keep the boards 
 clear of each other in the conveyor. A 5/8-inch chain with a link opening of about 
 1-1/2 by 5 inches is suitable. Wood cleats are attached at approximately 4-foot 
 intervals, but the exact spacing depends upon the diameter and tooth spacing of the 
 drive sprocket; cleats are spaced to ride between adjoining teeth but do not engage 
 them. The cleats are made of hardwood strips, about 1-1/2 by 3 hy l6 inches, run 
 through the link and strapped with metal. The plan (fig. l) shows an idle pulley 
 designed to take up slack. A less desirable drive dispenses with this, powering 
 the conveyor through the pulley at the end of ITU I 1 minli nn flpT* t.hp saw. Details 
 at the burner end are not shown, but provision! mLifcf Jb/tpnada J. a. fores' L9BJL setting 
 the conveyor afire. This is accomplished by using a m^a4-'weVi^TT^c]lined from the 
 chain end down into the fire pit. To prevent /smoke from blowing to ttte mill, the 
 burner should be at least 75 feet from the baik of the- mill and downwind from the 
 prevailing wind direction. w ' ^ I Jg^ 
 
 FAS. - Un lV of Ror . 
 
 rid 
 
 Rept. No. 899-21 (>JW I'tYY 
 
 mtributed by 
 J . Telford 
 |eptember 19^4 
 ievised by 
 F. B. Malcolm 
 December 1958 
 
 t Maintained at Madison 5, Wisconsin in cooperation with the University of Wisconsin 
 
UNIVERSITY OF FLORIDA 
 
 3 1262 08926 9913 
 
 ELEVATION 
 
 PLAN VIEW 
 
 >m 
 
 i "IT' ' 
 
 I CHAIN CLEAT 5 
 
 Vy TOOTH OF 
 SPROCKET 
 WHEEL 
 
 2"X /0~ 
 
 -SPROCKET WHEEL ^H^^p^^ l 
 
 TO TAKE UP 
 SLACK 
 
 SECTION A-A 
 
 DETAIL OF DRIVE ASSEMBLY 
 
 
 ' .ii mill conveyor