Wood Harvesting with Hand Tools - An Illustrated Training Manual (ILO, 1989, 128 p.): CROSS-CUT SAWS: MAINTAINING A RAKER-TOOTH CROSS-CUT SAW

Wood Harvesting with Hand Tools - An Illustrated Training Manual (ILO, 1989, 128 p.)

(introduction...)

INTRODUCTION

BASIC WORK AND MAINTENANCE TOOLS

HAND TOOLS FOR WOOD HARVESTING

FILES

GRINDSTONES AND WHETSTONES

SPLITTING HAMMER AND WEDGES

MAKING TOOL HANDLES

AXES

USE AND TYPES OF AXES

MAINTAINING AN AXE

MAKING AN AXE HANDLE

SHAFTING AN AXE

BOW SAWS

USE AND TYPES OF BOW SAWS

CROSS-CUT SAWS

TYPES OF CROSS-CUT SAWS

MAINTENANCE TOOLS FOR CROSS-CUT SAWS

FILING VICES, SELF-MADE

FILING VICES, COMMERCIALLY-MADE

MAINTAINING A PEG-TOOTH CROSS-CUT SAW

TYPES OF RAKER-TOOTH CROSS-CUT SAWS

MAINTAINING A RAKER-TOOTH CROSS-CUT SAW

MAJOR OVERHAUL OF CROSS-CUT SAWS

THE WORKER

CLOTHING, PERSONAL PROTECTIVE EQUIPMENT, FIRST-AID EQUIPMENT

FOOD, NUTRITION AND REST

WORKING POSTURES AND MOVEMENTS

WORK PLANNING AND ORGANISATION

ACCIDENT PREVENTION

TREE FELLING

PREPARATION FOR TREE FELLING

TREE FELLING WITH AXE AND BOW SAW

TREE FELLING WITH AXE AND CROSS-CUT SAW

PRECAUTIONS WHEN MAKING THE UNDERCUT AND THE BACK CUT

FELLING TREES LEANING INTO THE PLANNED FELLING DIRECTION

FELLING TREES LEANING TO THE SIDE

TREE FELLING IN DENSE TROPICAL FORESTS

FELLING OF TREES WITH PLANK BUTTRESSES

WOOD WASTAGE DUE TO POOR WORKING TECHNIQUES IN FELLING

RELEASING LODGED TREES

RELEASING LODGED TREES WITH SIMPLE TOOLS

RELEASING LODGED TREES WITH SPECIAL EQUIPMENT AND MACHINES

DEBRANCHING AND DEBARKING

DEBRANCHING

DEBARKING

CROSS-CUTTING

GENERAL RULES FOR CROSS-CUTTING

TOOLS FOR CROSS-CUTTING

SUPPORTS AND TRESTLES

CROSS-CUTTING OF TREES UNDER TENSION

WOOD WASTAGE IN CROSS-CUTTING

CUTTING WINDFALLS

WOOD SPLITTING

WOOD HANDLING AND TRANSPORT

HANDLING BILLETS AND LOGS

MANUAL TRANSPORT OF SMALLER-SIZED WOOD

USE OF SKIDDING SULKIES

SLIDING WOOD DOWNHILL

STACKING AND STORING OF WOOD

PIT-SAWING

TRAINING IN WOOD HARVESTING

OTHER ILO PUBLICATIONS

BACK COVER

MAINTAINING A RAKER-TOOTH CROSS-CUT SAW

Maintenance work follows the same pattern as for peg-tooth saws except that, additionally, raker adjustment is needed. The saw is held at all times in a vertical position during maintenance work.

Jointing is done in exactly the same way as for peg-tooth saws (1).

Raker adjustment. The raker adjuster, correctly set, is placed over a raker (2). Holding the tool firmly against the saw, the raker is filed flush with the tool guide plate (2a). The raker depth should be 0.2-0.5 mm for hard wood and 0.6-1.0 mm for soft wood (2b). The correct depth must be found under working conditions and will be indicated by properly-shaped saw chips.

Raker filing is done after adjusting the raker height (3). It is continued until the flat is as small as possible. Horizontal file strokes are used (3a). The raker angle should be 90°. It can be checked easily during filing with the top end of the mill-saw file (3b).

Cutter teeth filing is done with the saw in the oblique position (4). A top angle of 70 and a side angle of 35 must be produced. Filing strokes should not exceed 60 per minute. The full length of the file is used and an even pressure put on the file. Check the angles with the gauge frequently and when the flat almost disappears, tap the top of the tooth with the file handle or small piece of wood. This gives a true picture of how much flat is left. The last strokes with the file must be very gentle. Sharpening is finished when the flat is just about to disappear.

Figure

Deburring. Put the saw in a vertical position. The fine side of the whetstone is run along both sides of the saw to remove burrs (1). Be careful not to touch the sharp teeth with the fingers.

Setting (2). Check that the saw is held very firmly in the vice. For a right-handed man, the left arm is put over the saw, taking care not to catch the saw with the arm or body, and the anvil held in the left hand. Those teeth with the bevels towards the body are set first. The anvil is placed against the back of the cutter. The cutter is set with short and firm strokes of the setting hammer held in the right hand (2a, 2b).

The setting indicator is used to check the set of each tooth (3). The correct saw set for hard wood is 0.1-0.2 mm, for soft wood 0.2-0.4 mm (4). Insufficient set is corrected at once by further hammer strokes. If the set is too great it is removed with the setting hammer after the position of the anvil has been changed (5). After setting one side, the saw is turned round and the other side is set.

Note: The first six teeth on either end of the saw need no setting.

Setting normally follows cutter teeth filing but the order can also be reversed.

Deepening of gullets. At intervals of about four weeks, it is necessary to deepen the gullets on the cutters (6a) and the gullets between the rakers (6b) with the millsaw file and the big gullets between the rakers and the cutters (6c) with the round file.

Figure