11.Causes and Operator Prevention of Kickback:
Kickback is a sudden reaction to a pinched, bound or misaligned saw blade, causing an uncontrolled saw to lift up and out of the workpiece toward the operator.
When the blade is pinched or bound tightly by the kerf closing down, the blade stalls and the motor reaction drives the unit rapidly back toward the operator.
If the blade becomes twisted or misaligned in the cut, the teeth at the back edge of the blade can dig into the top surface of the wood causing the blade to climb out of the kerf and jump back toward operator.
Kickback is the result of tool misuse and/or incorrect operating procedures or conditions and can be avoided by taking proper precautions as given below.
Maintain a firm grip with both hands on the saw and position your body and arm t o allow you t o resist KICKBACK forces. KICKBACK forces can be controlled by the operator, if proper precautions are taken.
When blade is binding, or when interrupting a cut for any reason, release the trigger and hold the saw motionless in the material untilthe blade comes t o a complete stop. Never attempt to remove the saw from the work or pull the saw backward while the blade is in motion or KICKBACK may occur. Investigate and take corrective actions to eliminate the cause of blade binding.
When restarting a saw in the workpiece, center the saw blade in the kerf and check that saw teeth are not engaged into the material. If saw blade is binding, it may walk up or KICKBACK from the workpiece as the saw is restarted.
Support large panels t o miniinize the risk of blade pinching and KICKBACK. Large panels tend to sag under their own weight. Supports must be placed under the panel on both sides, near the line of cut and near the edge of the panel as shown in Fig. 1.
To minimize the risk of blade pinching and kickback. When cutting operation requires the resting of the saw on the work piece, the saw shall be rested on the larger portion and the smaller x e cut off.
To avoid kickback, do support board I or panel near the cut.
Fig. 1
Don't support board or panel away or panel near the cut.
Fig. :
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