TECHNICAL INFORMATION
DIAMOND CORE BIT DRILLING TIPS & TROUBLE SHOOTING
Always secure the drill rig either with a mechanical anchor, vacuum system or by use of the jack screw. NEVER stand on the base and drill without anchoring. Level the drill rig by use of the base leveling screws, and a small level attached to the column permanently or by a magnetic strip on the level. This procedure will ensure a perpendicular hole. Never let the bit spin in the hole without applied pressure. This will cause the diamonds to round off and the bit segments will heat and glaze over. Turn on water before starting the drill motor. Otherwise, the water jacket seals heat up and become brittle, losing water. When your bit encounters steel (rebar), relax pressure about 1/3 and allow the bit to cut at its own rate. DO NOT PUSH THE BIT.
When drilling high PSI concrete or concrete with very hard aggregate (i.e., river rock, flint rock, etc.), the bit will sometimes glaze over. To open or redress the bit, do one of the following: • Decrease water by 1/2 for a few minutes and as the bit starts to increase speed, gradually increase the water until the flow is back to the original state. • Pour masonry sand into the slurry then follow the above directions. • Add a sandblast media such as “Black Beauty” to the slurry and follow the above directions. • Drill the bit into a cement block, soft vitrified grinding wheel or cinder block. Repeat the procedure until the bit is open again. When finished drilling, turn the water down very low and back the core bit out of the hole with the motor running.
SYMPTOM CAUSE
REMEDY
Loss of segment
Bit too hard for the material it is drilling, causing it to pound and fatigue.
Use a softer bond if possible. Increase motor RPM if possible.
Overheating due to insufficient water for cooling and flushing.
Increase water flow to where slurry is milky and flows easily.
Machine setup is not rigid or loose material is in the cut and the bit segment hangs
Tighten anchor, check vacuum system for proper vacuum pressure.
Snagging cable, when drilling prestressed concrete
Use a bit with more segments, such as a Husqvarna B735 PS prestressed core bit.
Segment cracking Bit is too hard for the material being drilled.
Use a softer bit if possible. Increase motor RPM.
Machine setup is not rigid.
Tighten anchor, check vacuum system.
Barrel cracking
Too much feed pressure.
Back off on the pressure.
Segment too hard for material being drilled.
Use bit with softer segment.
Extension Cord Size in American Wire Gauge (AWG) 3 Conductor with ground, SO/SJ type cord, length in feet
2 conductor with ground, SO type cord, length in feet
3-PHASE, FLA
25
50
75
100
150
200
1-PHASE, FLA
25
50
75
100
150
7.1 - 10
16
14
12
12
10
8
1.0 - 5.0
18
18
18
16
14
200 14
10.1 - 15
14
12
10
10
8
6
5.1 - 10
18
16
14
14
12
10
15.1 - 20
12
12
10
8
6
6
10.1 - 15
14
14
12
12
10
8
20.1 - 25
10
10
8
8
6
6
15.1 - 20
12
12
12
10
8
8
25.1 - 30
8
8
8
6
6
4
20.1 - 25
12
12
10
10
8
6
30.1 - 35
8
8
6
6
4
4
25.1 - 30
10
10
10
8
6
6
35.1 - 40
6
6
6
6
4
2
30.1 - 35
8
8
8
8
6
6
40.1 - 45
6
6
6
6
4
2
35.1 - 40
8
8
8
8
6
6
45.1 - 50
4
4
4
4
4
2
40.1 - 45
6
6
6
6
6
4
The above tables are based on SO/SJ type cord (Power cord for portable tools and equipment) in an ambient temperature of 86° F (30° C). For higher operating temperatures, use the chart to the right with multipliers for tool amperage.
45.1 - 50
6
6
6
6
6
4
Degrees F
Degrees C
Multiplier
All power cord connectors must be in accordance with NEC standards.
87 - 95
31 - 35
104%
96 - 104
36 - 40
110%
104 - 113
41 - 45
115%
Generators must be commercial or industrial type generators and be capable of handling the wattage required for starting the portable tools or equipment. Check and comply with all local codes and regulations when using portable generators.
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