DeWalt DW930 Manual De Instrucciones página 14

DW936/384286-01 3/15/00
cutting line until cut is completed. Release trigger and allow blade to
stop completely before withdrawing the blade from the material.
When starting each new cut, repeat as above. Never tie the blade
guard in a raised position. Never move the saw backwards when
pocket cutting. This may cause the unit to raise up off of the work
surface which could cause injury.
Kickback
When the saw blade becomes pinched or twisted in the cut, kickback
can occur. The saw is thrust rapidly back 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 backward. When
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 the
operator. Kickback is more likely to occur when any of the following
conditions exist.
Improper work piece support
• Sagging or improper lifting of the cutoff piece causing pinching of
the blade.
• Cutting through material supported at the outer ends only (FIG. 9).
As the material weakens it sags, closing down the kerf and
pinching the blade.
• Cutting off a cantilevered or overhanging piece of material from the
bottom up in a vertical direction. The falling cut off piece can pinch
the blade.
• Cutting off long narrow strips (as in ripping). The cutoff strip can
sag or twist closing the kerf and pinching the blade.
• Snagging the lower guard on a surface below the material being
cut, momentarily reducing operator control. The saw can lift
partially out of the cut, increasing the chance of blade twist.
Improper depth of cut setting on saw
Using the saw with an excessive depth of cut setting increases
loading on the unit and susceptibility to twisting of the blade in the kerf.
It also increases the surface area of the blade available for pinching
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under conditions of kerf close down.
Blade twisting (Misalignment in Cut)
Pushing harder to cut through a knot, or hard grain area can cause
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blade to twist.
Trying to turn the saw in the cut (trying to get back on the marked
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line) can cause blade twist.
Extended reach or operating saw with poor body control (out of
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balance) can result in twisting the blade.
Changing grip or body position while cutting can result in blade
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twist.
Backing unit up to clear blade can lead to twist if not done carefully.
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Insufficient allowance for particularly tough materials
Materials that require extra attention: wet lumber, green lumber
(material freshly cut or not kiln dried), pressure treated lumber
(material treated with preservatives or anti-rot chemicals)
Use of dull or dirty blades
Dull blades cause increased loading of the saw. To compensate, an
operator will usually push harder which further loads the unit and
promotes twisting of the blade in the kerf. Worn blades may also have
insufficient body clearance which increases the chance of binding and
increased loading.
Lifting the saw when making bevel cuts
Bevel cuts require special operator attention to proper cutting
techniques - especially guidance of the saw. Both blade angle to the
shoe and greater blade surface in the material increase the chance for
binding and misalignment (twist) to occur.
Restarting a cut with the blade teeth jammed against the
material
The saw should be brought up to full operating speed before starting
a cut or restarting a cut after the unit has been stopped with the blade
in the kerf. Failure to do so can cause stalling and kickback.
Any other conditions which could result in pinching, binding, twisting,
or misalignment of the blade could cause kickback. Refer to sections
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