The Core Drilling Operation; Working Principle - Hilti DD AF-CA Manual De Instrucciones

8. Connect the water hose that runs to the core drilling
machine.
9. Connect the water supply to the drilling feed unit.
10. Remove the protective caps from the connector and
the connecting cable.
11. CAUTION Connect a 110 volt drilling feed unit only
to a 110 volt core drilling machine.
Connect the connecting cable for the drilling feed
unit to the connector on the core drilling machine.
12. Fit the protective caps into each other in order to
keep them clean.

6 The core drilling operation

NOTE
Switching other power tools or appliances on and off may
cause undervoltage and / or overvoltage peaks, resulting
in damage to the power tool or appliance. Never operate
other power tools or appliances from the generator or
transformer at the same time.
DANGER
Failure to keep clear of the danger area may result in a
risk of crushing or cutting injury.
The drilling feed unit is always in Cut Assist mode imme-
diately after switching on and starts drilling automatically
as soon as the switch on the core drilling machine is
operated. When the drilling operation is started, the core
bit is moved toward the working surface. There is a risk
of injury in the vicinity of the core drilling machine, the
core bit and at the point where the hole is to be drilled.
Before switching on the core drilling machine, check that
no persons are within the danger area.
WARNING
There is a risk of crushing or cutting injury when the core
drilling system contacts the working surface with the core
bit.
Keep everything clear of the area between the core bit
and the working surface.
CAUTION
The emergency stop button does not function if the
drilling feed unit is not connected to the core drilling
machine.
Do not carry out manual core drilling when the drilling
feed unit is fitted but not connected.
Remove the drilling feed unit when it is not connected to
the core drilling machine or, alternatively, connect it to
the core drilling machine.

6.1 Working principle

In Cut Assist mode, the core drilling operation begins
with the core bit being moved (drilling feed movement)
towards the surface in which the hole is to be drilled.
The core bit does not rotate while this is taking place. As
soon as the core bit contacts the surface it is retracted a
short distance. The core bit then begins to rotate slowly
(starting speed). The system switches on the water supply
5.2 Providing water cooling
NOTE
Both the drilling feed unit and the core drilling ma-
chine are water cooled devices.
Before operating the equipment, always check that a
water hose is correctly connected to the water input
connector for the drilling feed unit cooling circuit. This
also applies when carrying out dry drilling applications.
Check that the minimum water flow rate meets at least
the requirements given in the technical data.
and drills at low speed until adequate hole-starting depth
is reached.
Once the required starting depth has been reached the
system continues drilling at the optimum speed and with
optimum power. The Iron Boost function is activated
automatically when the core bit contacts a reinforcing
bar, thereby adjusting the power output for optimum
performance while cutting through the reinforcement.
Thin, weak reinforcing bars may not be detected by the
drilling feed unit, in which case the Iron Boost function
will not be activated. This has only a very slight effect on
drilling performance.
When drilling a blind hole (not all the way through), the
drilling feed unit stops the advance movement as soon
as the carriage contacts the depth gauge.
NOTE
When through holes are drilled without using a depth
gauge, the core bit feed movement continues until the
core bit projects approx. 3 cm beyond the through hole
exit.
At the end of the drilling operation the core bit should be
retracted so that just the tip of the core bit remains in the
hole, and the water flow then switched off.
6.2 Drilling using Cut Assist mode
WARNING
The rotating hand wheel presents a risk of injury! Remove
the hand wheel from the carriage before you begin
drilling using CutAssist.
NOTE
If you press the Iron Boost button on the core drilling
machine while using Cut Assist mode, automatic power
regulation when drilling through reinforcing bars will be
deactivated. As a result, until the end of the drilling
operation, you will then have to regulate the drilling power
manually when drilling through reinforcing bars.
To drill a hole automatically using Cut Assist, proceed as
follows:
en
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