Évaluations - 4, GPA: 3.5
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Facilité d'utilisation
These things influence the direction in which the tree will fall. Do not try to fell a tree along a line different from its natural line of fall. • The chain saw operator should keep on the uphill side of the terrain as the tree is likely to roll or slide downhill after it is felled. • Remove dirt, stones, loose bark, nails, staples, and wire from the tree where felling cuts are to be made. • Notched Undercut. Cut a notch about 1/3 the diameter of the tree, perpendicular to the direction of fall. Make the cuts of the notch so they intersect at a right angle to the line of fall. This notch should be cleaned out to leave a straight line. To keep the weight of the wood off the saw, always make the lower cut of the notch before the upper cut. See Figure 14. hINGE 2 in. OR 1/10 DIA NOTCh - AppROX. 1/3 DIAMETER Of TRuNK BACK CuT 2 in. Fig. 1 pLANNED pATh Of sAfE RETREAT 135° fROM pLANNED LINE Of fALL pLANNED LINE Of fALL Fig. 13 sAfE RETREAT ZONE pLANNED LINE Of fALL 45° 45° 90° 135° 135° sAfE RETREAT ZONE sAfE RETREAT ZONE 90° 15 16 . Felling Backcut. The backcut is always made level and horizontal, and at a minimum of 2 in. above the horizontal cut of the notch. See Figures 14 - 15. . Never cut through to the notch. Always leave a band of wood between the notch and backcut (approximately 2 in. or 1/10 the diameter of the tree). This is called "hinge" or “hingewood.” It controls the fall of the tree and prevents slipping or twisting or shoot-back of the tree off the stump. See Figures 14 - 15. . On large diameter trees, stop the back cut before it is deep enough for the tree to either fall or settle back on the stump. Then insert soft wooden or plastic wedges into the cut so they do not touch the chain. The wedges can be driven in, little by little, to help jack the tree over. See Figure 16. NOTE: When bucking or felling with a wedge, it may be necessary to remove the SAFE-T-TIP® anti-kickback device to allow the bar to be drawn through the cut. After the cut is complete, the tip should be reinstalled immediately. . As tree starts to fall, stop the chain saw and put it down immediately. Retreat along the cleared path, but watch the action in case something falls your way. Be alert for overhead limbs or branches that may fall and watch your footing. WARNING: Never cut through to the notch when making a backcut. The hinge controls the fall of the tree, this is the section of wood between the notch and backcut. NOTCH BACK CUT Fig. 16 Fig. 15 kickback Fig. 17 HINGE wedge OPERATION Bucking See Figures 17 - 20. Bucking is the term used for cutting a fallen tree to the desired log length. . Always make sure your footing is secure and your weight is distributed evenly on both feet. . Cut only one log at a time. . Support small logs on a saw horse or another log while bucking. . Keep a clear cutting area. Make sure that no objects can contact the guide bar nose and chain during cutting, this can cause kickback. To avoid the danger, keep the SAFET- TIP® anti-kickback device attached while cutting. Refer to Precautions Against Kickback earlier in this manual. . When bucking on a slope, always stand on the uphill side of the log. To maintain complete control of the chain saw when cutting through the log, 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. . 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. Fig. 18 17 BUCKING Logs Under Stress See Figures 19 - 20. 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 underbucking. 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 the first cut deeper than 1/3 of the diameter of the log. Give special attention to logs under stress to prevent 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 20. 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...
Ce manuel est également adapté pour les modèles :Benzo et scies - P540 (1.83 mb)