90°. The beam is then directed at an alignment disk followed by a further mirror that turns the beam
through another 90°. These can be adjusted in two stages to focus the laser beam. The beam is
then directed through a further alignment disk followed by a further mirror that turns the beam
through another 90° and adds cross hairs. On leaving the optical head the beam is thereafter
directed at the work piece. There is a shutter on the output of the beam shaper that can be closed
mechanically to block the path of the laser beam and electrically shut off the KLMC box.
The DHS laser system operates from instructions that are loaded onto a computer. Various operating
menus are accessible through the computer and are presented in different windows. The control
system manages the position of the laser head, laser intensity, rates of acceleration and
deceleration, cutting speed and many other fine adjustments.
Cutting or engraving instructions on the computer are converted with the KCAM software into
information that is recognized by the machine. KCAM software is used to control all movements of
the machine and the intensity of the laser.
Any safety limitations such as maximum laser intensity, cutting speeds or limits of travel are
controlled by software and independently backed up by electromechanical control systems or
firmware to establish Category-3 architecture as detailed in EN13849-1.
The acceptable engraving speed range is from 0.01 inches per second to 25 inches per second for
non-metallic materials and 0.01 inches per second to 20 inches per second for metals. The
acceptable cutting speed range is from 0.01 inches per second to 10 inches per second for non-
metallic materials and 0.01 inches per second to 5 inches per second for metals. In one mode of
operation the modulation frequency sets the intensity of the laser. This ranges from 50 – 10000 Hz.
In another mode of operation a pulse rate sets the intensity of the laser. This ranges from 0 to 600
pulses per inch.
The 150W machine must be configured with metal cutting hardware to successfully cut metal. High
pressure oxygen must be passed through the optics to initiate a cut and achieve a clean edge. The
KCAM software and a pressure regulator valve control the use of oxygen. A 150 watt laser can cut up
to .090” mild steel and up to .075” stainless steel.
A blower pulls through two 4” ports at the back of the table. This blower removes fumes and small
debris that drops into the table chamber. A second blower is connected at the nozzle assembly.
Intended Purpose
The DHS machine is capable of operating at speeds of up to 25 inches per second using a laser beam
that operates at a consistent power level to provide high quality laser cutting or engraving over the
entire area of the laser worktop. A gantry, which spans the full width of the worktop, carries one
optical head. The machine can achieve resolutions from 50 dpi to 1200 dpi. Normally the machine is
offered with resolutions from 300 dpi and 600 dpi.
Cutting and engraving speeds are determined by the laser size, material being processed, and the
desired edge quality. The machine operates at its highest speed when cutting in straight lines, and
slows down when cutting patterns as they become more intricate. Typical cutting speeds range from
150 mm (6 inches) per minute up to 15 m (600 inches) per minute. Cutting speeds and laser power
are adjusted by selecting line colors that are generated by KCAM software.
The Kern DHS model is designed to cut wood, metal, and plastic. Other materials can be cut, but a
MSDS sheet must first be reviewed first. As a result of laser cutting and engraving operations, many
of these materials produce toxic fumes when they are heated therefore blowers are provided to
remove such material. Material that is collected must be removed by a dust extraction system
provided by the user. The required extraction rate is 42,475 Liters/minute (1500 cfm). See Material
Capability and Fume Extraction page. If there are any doubts, users should perform a hazard and
risk assessment on given material or contact Kern for advice.
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