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NOTE: the left and right side gear selectors have a different engagement design:
For The LEFT HAND SLIDER must ALWAYS ensure that the machine is FULLY STOPPED before attempting
to change gears! NEVER change the Left hand slider gears on a running machine!
For the RIGHT HAND SLIDER the gears select by engagement dogs, similar to a motorcycle transmission
design. These MUST BE SELECTED BY TURNING THE ARBOR to allow the dogs to engage.
CAUTION: Ensure that that gears engage fully.
VARIABLE MOTOR SPEED MODELS ONLY
The electronic variable motor speed control allows the motor speed to be lowered for further flexibility for
adjusting the cutting speed to suit the size of cutter and type of
material. Simply turn the thumb wheel to raise or lower the motor
speed electronically.
NOTE: whenever possible, it is always preferable to lower the speed
by changing the gear rather than lowering the motor speed. A
slower motor speed will have less cooling and somewhat less
torque so always try to keep the motor going as fast as possible.
Only lower the motor speed if you have no other option.
(For example: If you need the RPM at about 100/min, it is much
better to use 1st gear at full motor speed than to use 3rd gear at
minimum motor speed.)
Avoid overheating the motor:
When using the machine at or near maximum capacity with a slow motor speed the motor will be at
maximum stress and very hot. After each cut is finished,
ALWAYS
cool the motor by running at no load at the
maximum motor speed for a few minutes.
CUTTING SPEEDS
The type of material to be drilled, its hardness and thickness will all greatly affect the recommended cutting
speed. See the chart below for general guidelines for cutting speeds. Use the formula to determine the
recommended RPM for the diameter of annular cutter being used:
RECOMMENDED SURFACE SPEEDS
Note: work materials which have been flame cut will be heat treated in the affected area. These areas
will require much slower cutting speeds.
Variable Speed Wheel
Summary of Contents for MD120/4
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