OPERATION
handles. Do not let the chain contact the ground. After completing the cut, wait for the saw chain to stop before you move the chain saw. Always stop the motor before moving from tree to tree.
Sometimes it is impossible to avoid pinching (with just standard cutting techniques) or difficult to predict which way a log will settle when cut. To avoid pinching while cutting, rotate or move the log so that the pinch is eliminated.
BUCKING LOGS UNDER STRESS
See Figures 18 - 19.
When the log is supported along its entire length, it should be cut from the top or overbucking.
When the log is supported on one end, cut 1/3 the diameter from the underside or underbuck- ing. Then make the finishing cut by overbucking to meet the first cut.
As the log is being cut, it will tend to bend. The saw can become pinched or hung in the log if you make thefirstcutdeeperthan1/3ofthediameterofthelog.
Give special attention to logs under stress to pre- vent the bar and chain from pinching.
When bucking on a slope, always stand on the uphill side of the log as shown in figure 18. When “cutting through,” to maintain complete control of the chain saw, release the cutting pressure near the end of the cut without relaxing your grip on the chain saw handles. Do not let the chain contact the ground. After completing the cut, wait for the saw chain to stop before you move the chain saw. Always stop the motor before moving from tree to tree.
TYPES OF CUTTING USED
See Figure 19.
OVERBUCKING
Begin on the top side of the log with the bottom of the saw against the log; exert light pressure downward. Note that the saw will tend to pull away from you.
UNDERBUCKING
Begin on the under side of the log with the top of the saw against the log; exert light pressure upward. During underbucking, the saw will tend to push back at you. Be prepared for this reaction and hold the saw firmly to maintain control.
WARNING:
Never climb into a tree to limb or prune. Do not stand on ladders, platforms, a log, or in any position which can cause you to lose your bal- ance or control of the saw.
LOG SUPPORTED AT ONE END:
LOAD
FINISHING CUT
1ST CUT
1/3 DIA
LOG SUPPORTED AT BOTH ENDS: LOAD
1ST CUT 1/3 DIA
FINISHING CUT | Fig. 18 |
| |
OVERBUCKING |
|
UNDERBUCKING
Fig. 19
17 - English