Machine description
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Overall
Housed in a very attractive
enamelled steel case!

Tube
40W sealed CO2 laser tube.
Wavelength 10.6 microns (far infrared).
Quoted lifetime is 800-1000
hours, but it isn't specified at what current this value was obtained.
Presumably running the tube harder will reduce its lifetime.
The actual time spent cutting
is probably small, given the time setting up the work, calculating
settings etc.
Water cooling provided
by a little aquarium pump.

Mechanics & beam delivery
Stepper motor driven axes
with an on-board motion control card. It uses the usual 3-mirror flying
optics arrangement to deliver the beam to the cutting head.
Each mirror is a gold-coated
front-surface mirror, about 20mm diameter. The lens is zinc selenide,
AR-coated with a focal length of around 50mm.
The cutting bed can be
lowered to accomodate articles up to 5cm in thickness. There is also
a honeycomb cutting table. Second picture below shows adjustment knob
for the table height.
The optimum distance from
the top of the lens support plate to the surface of the material being
cut appears to be 57mm.
Control panel & electronics
Front panel controls are
keyswitch for main power, laser on switch, lighting on switch, laser
test buttons, current adjust, and emergency stop.
Important safety
note: The
laser power supply (the largest PCB in the enclosure) is a switchmode
supply run from the mains. As a result, the current adjust potentiometer
is floating at half mains potential (about 120V). I mention this in
case you try to make some circuit to control the laser current automatically,
e.g. from a computer!
The start/stop signal for
the laser is OK, because it is optoisolated from the laser power supply.
I would also be a bit wary
of whether the current control potentiometer can actually withstand
that voltage to earth - note that the pot shaft is metal! When I make
the attachment for a multiturn knob, I'll probably make it insulating,
just in case.
Fume extraction
Fan on the rear of the
casing, pulling smoke away from the cutting area. Maybe not the most
powerful, but it does work.
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