8MANTA I
Revision 03/05, Effective Date March 2, 2005
9
MANTA I Revision 03/05, Effective Date March 2, 2005
The MK-Manta I will operate in either a high or low gear speed. This speed combined
with applied pressure provides the cutting action for the core bit. Speed selection and
pressure are determined by hardness of material, aggregate size and grade of diamond
core bit. Generally, harder material and larger aggregates require more speed and
pressure. Use low speed for large diameter bits and high speed for small diameter bits.
Changing of the speeds is accomplished by using the speed shift lever built into the
gear case.
Notice: Change the gears only when the motor is off.
All building materials and work surfaces are composed of aggregate of various size.
Aggregates are materials such as gravel or crushed stone. The size of the grains and
the hardness of the material affects the speed of drilling. Most building materials contain
some type of steel reinforcements. All MK bits are designed to cut through these types
of reinforcing steel. However, bits should never be used for drilling solid steel plates.
Proper selection of the diamond core bit should be based on material to be drilled and
performance requirements.
Steady, even pressure assures accurate holes and longer bit life. Always maintain
consistent pressure so that the bit is constantly cutting.
Notice: Too much pressure will damage the bit and motor. Too little pressure will
glaze over the diamonds, reducing cutting efficiency and prematurely wearing the bit.
The ammeter is the gauge on the Control Box. It provides pressure feedback information
during drilling, allowing the operator to help prevent motor overload and premature bit
wear. The green area is the operating range, and the red area is the overload range.
Generally, the operator should keep the ammeter needle in the upper area of the
operating range for large diameter bits, and in the lower green area for small diameter
bits. If the bit contacts steel reinforcing rods, the needle on the ammeter may jump
slightly showing a heavier load. If this occurs, do not decrease pressure or you may
damage the diamonds. The Manta may be operated with the ammeter needle into the
red area for the short period of time that it takes to cut through a steel rod.
An adequate supply of clean water is necessary for drilling. Connect the water supply
hose to the hose fitting on the output of core drill motor. Take precautions that the water
supply will not be interrupted during the drilling operations.
Notice: If a bit is run dry it can be ruined in a few seconds.
Water Supply
Drilling Speeds
Drilling Pressure
and the Ammeter
Manufacturer Model # AMP Volts Speed(RPM) Suggested Dia. in
Medium Aggregate
Eibenstock EBM
300/3 P
20 120 Low – 270
Medium – 700
High – 1250
Low – 4”
Medium – 2”-6”
High – 3/4”-4”
Milwaukee 4004 20 120 Low – 300
High – 600
Low – 4”
High – 14”
Milwaukee 4090 15 120 Low – 375
High – 750
Low – 5”-8”
High – 2 1/2”-5”
Milwaukee 4094 20 120 Low – 450
High – 900
Low – 6”-10”
High – 2”-6”
Milwaukee 4096 20 120 Low – 450
High – 900
Low – 6”-10”
High – 2”-6”
Milwaukee 4097-20 15 120 Low – 500
High – 1000
Low – 1 1/4”
High – 5”
