Tool Tips - Bosch DH712VC Operating/Safety Instructions Manual

2610048701.qxp_DH712VC 10/5/17 8:01 AM Page 9
VARIABLE SPEED DIAL
Your tool is equipped with a variable speed
dial. The speed and impact force can be
adjusted by rotating the dial. Higher speeds
and impact force work best for faster
penetration when
masonry/concrete material. Slower speeds
work best for chiseling material such as plaster
or tile (Fig. 6).
SELECTOR DIAL
The selector dial allows the tool to be set for
demo hammer or vario-lock operations
(Fig. 7).
SELECTOR DIAL - "VARIO-LOCK"
The vario-lock can be set in any one of sixteen
positions (22.5˚ increments). Choose a
position which is best suited for your
operation. The Vario-Lock position is intended
for use with chipping bits such as bull points,
spades, gouges, etc.
Turn the selector dial, to the "vario-lock"
setting. Next, rotate the locking sleeve,
along with the accessory, to the desired
position. Then turn the selector dial to the
"chisel" setting and slightly turn the locking
sleeve to have it automatically lock into a
definite position.
CONSTANT RESPONSE CIRCUITRY
The internal electronic feedback system
provides a "soft start", which will reduce the
stresses that occur from a high torque start.
The system also helps to keep the pre-
selected impact rate virtually constant between
no-load and load conditions.
VIBRATION DAMPER HANDLE /
HAMMER MECHANISM
The integrated vibration damper in the main
handle and hammer mechanism reduces
vibrations (Fig. 6).
For the best penetration rates in concrete, run
the tool with a steady pressure, but do not use
excessive force as this will decrease the
efficiency of the tool.
All hammers require a short period of time to
warm up. Depending on the room temperature,
this time may vary from approximately 15
seconds (90˚F) to 2 minutes (32˚F). A new
hammer requires a break-in period before full
performance is realized. This period may
require up to 5 hours of operation.
chiseling in hard

Tool Tips

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FIG. 6
FIG. 7
2
An electric hammer is likely to be the most
expensive portable tool at the construction job.
The long wear and efficient operation of the
BOSCH hammers will more than justify the
cost for tools of this type. As earlier pointed
out, sharp accessories as well as clean air
vents are necessary for efficient operation.
Establish and follow a set maintenance
program.
VIBRATION DAMPER
HANDLE / HAMMER
MECHANISM
SERVICE
REMINDER
LIGHT
VARIABLE
SPEED DIAL
1