virginia abraives VA-CD3, Operating Manual

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7) Various Materials:
If vibration or clutch slip occurs when drilling reinforced concrete, the drill thrust
should be reduced. If broken concrete or gravel falls into the bore, rebar may catch
on gaps in the core bit segments resulting in overheating of the motor. Remove the
drill bit from the hole and clean the gap. Let the drill cool down before continuing
to drill. When drilling thick asphalt, the load on the drill will be increased, take care
to drill slowly, uniformly, and monitor the motor speed. If the clutch slips
continuously, reduce the cutting pressure.
8) Remove drill core:
When the drill bit nearly drills through the slab or wall, take care to reduce the
cutting pressure to avoid a sudden breakthrough. Remove the core bit from the
work piece gently by:
- Remove bit by jogging the trigger
- Unplug drill from electrical source
- Clean the bit
- Gently tap core bit with non-metallic material and/or a rubber hammer to remove
the cored material from the inside of the bit
- Be careful in removing the core material and damaging the drill bit
- Continue operating
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9) Keep the motor ventilated during use:
During operating the ventilated notch of motor should not be clogged with dirt to
avoid overheating and damage to the motor.
10) Waterless operation prohibited:
When operating, there should be plenty of water flow onto the surface of the drill
bit to clean and cool the bit.
11) Keep the motor dry:
Keep the enclosure of the motor away from water to avoid electrical shock. Control
the water flow away from the operator and drill by drilling in a horizontal or vertical
downward orientation only.
When changing gears, the machine must be stopped. Unplug the machine. Turn the
adjustment knob by hand while gently turning the core bit by hand. This will allow the
gears to un-mesh and mesh in the newly selected speed. Never adjust the gears while the
motor is running. Doing so will damage the gears and void the warranty.
4. Structure, Feature, and Usage
This tool is a portable diamond core drill, it is designed for three-gear speeds.
High gear (gear III) is suitable for a core bits up to 2”.
Medium gear (gear II) is for core bits up to 3”.
When drilling holes greater than 3” a core rig must be used.
Low gear (gear I) is suitable for holes from 3 to 6” diameters. The core drill is equipped
with safety friction clutch which protects the user and the motor. See fig. 3 for an
expanded diagram of parts.