Maintenance And Inspection - HIKOKI VTP-18 Instrucciones De Manejo

7. IMPACT to ROTATION changeover (Fig. 2)
The Impact Drill can be switched from IMPACT
(impact plus rotation) to ROTATION (rotation only)
by simply turning the change ring.
When boring concrete, stone, tile or similar hard
materials, turn the change ring fully clockwise when
viewed from the drill chuck side. The drill head
impacts against the material while continuing to
rotate.
When boring metal, wood or plastic, turn the change
ring fully counterclockwise. The drill simply rotates
as an ordinary electric drill.
CAUTION
Do not use the Impact Drill in the IMPACT function
if the material can be bored by rotation only. Such
action will not only reduce drilling efficiency, but
may also damage the drill tip.
When changing over, ensure that the change ring
is turned as far as it will go.
8. Fixing the side handle
Loosen the knob bolt on the side handle, and attach
the side handle to the gear cover in a position
convenient for drilling.
Match the projecting part of the handle to the
groove on the gear cover, and firmly tighten the
knob bolt.
To remove the side handle, loosen the knob bolt
and rotate the handle.
To attach a depth stopper on the side handle, insert
the depth stopper into the U-shaped groove on the
side handle, adjust the position of the depth stopper
in accordance with the desired depth of the hole,
and firmly tighten the knob bolt.
PRACTICAL HANDLING PROCEDURES
1. Pressure
Drilling will NOT be accelerated by placing heavy
pressure on the drill. Such action will only result
in a damaged drill bit, decreased drilling efficiency,
and/or shortened service life of the drill.
2. Using a large diameter drill bit
When using the larger diameter drill bit, the larger
reactive force is applied on your arm. Be careful
not to lose control of the drill because of this
reactive force. To maintain firm control, establish
a good foothold, hold the drill tightly with both
hands, and ensure that the drill is vertical to the
material being drilled.
3. When drilling completely through the material
When the drill bit bores completely through the
material, careless handling often results in a broken
drill bit or damage to the drill body itself due to
the sudden movement of the drill.
Always be alert and ready to release the pushing
force when penetrating the material.
4. Switch operation
(1) VTP-18:
By pulling the trigger switch and depressing the
stopper, the switch is held in the ON position for
continuous operation. To turn the drill OFF, pull the
trigger switch again and release.
(2) VTV-18:
The rotational speed of the drill bit can be controlled
by varying the amount that the trigger switch is
pulled. Speed is low when the trigger switch is
pulled slightly and increases as the switch is pulled
more. Continuous operation may be attained by
pulling the trigger switch and depressing the stopper.
To turn the switch OFF, pull the trigger switch again
to disengage the stopper, and release the trigger
switch to its original position.
5. Precautions on Boring
The drill bit may become overheated during
operation; however, it is sufficiently operable. Do
not cool the drill bit in water or oil.
6. Caution concerning immediately after use
Immediately after use, while it is still revolving, if
the Drill is placed on a location where considerable
ground chips and dust have accumulated, dust may
occasionally be absorbed into the Drill mechanism.
Always pay attention to this possibility.

MAINTENANCE AND INSPECTION

1. Inspecting the Drill Bit
Continued use of a worn and/or damaged drill bit
will result in reduced drilling efficiency and may
seriously overload the drill motor. Inspect the drill
bit often and replace it with a new bit as necessary.
2. Inspecting the mounting screws
Regularly inspect all mounting screws and ensure
that they are properly tightened. Should any of the
screws be loose, retighten them immediately. Failure
to do so could result in serious hazard.
3. Inspecting the carbon brushes (Fig. 3)
The motor employs carbon brushes which are
consumable parts. Since excessively worn carbon
brushes can result in motor trouble, replace the
carbon brushes with new ones having the same
carbon brush No. shown in the figure when they
become worn to or near the "wear limit". In addition,
always keep carbon brushes clean and ensure that
they slide freely within the brush holders.
4. Replacing carbon brushes
Disassembling:
(1) Loosen the three screws on the handle cover, and
remove the handle cover. Remove the holder plates,
which keeps the brush holders in place, by removing
the stopper screws.
(2) Lift out the brush holders together with the carbon
brushes, while being very careful not to forcibly pull
the lead wires within the brush holders.
(3) Withdraw the brush terminals, and remove the
carbon brushes from the brush holders.
Reassembling:
(1) Place new carbon brushes into the brush holders,
and connect the brush terminals to the carbon
brushes.
(2) Return the brush holders and other parts to their
original positions, as illustrated in Fig. 4, press the
holder plates into position, and fasten it with the
stopper screws.
(3) Place the lead wire in the specified position.
Be very careful not to allow the lead wire to contact
the armature or rotating parts of the motor.
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