The Laser Cutting System
This is a front view of the laser cutter. The rectangular aluminum
block below the flat screen is the laser head.
Construction
The general idea of this CO2 laser system is that a beam is directed
down to a part for cutting. The part sits on a computer controlled
platform which moves the piece around the stationary laser
beam. Cutting is achived by passing the beam through a focusing
lens. A focused beam exits through the bottom of a cutting head
nozzle. Gas, such as oxygen, is fed into the side of the chamber below
the focusing lens. This gas exits the nozzle along with the beam and
the laser beam/oxygen combination serves to vaporize the steel for
cutting.
One thing that I discovered when making this system is that purchasing
the laser was the easy part; many other systems are required to be
on-line in order to achieve anything useful with the laser. To give
you an idea, this is a comprehensive diagram describing the basic
components of a CNC laser cutting system:
This is a picture organizing many of these components around the
central control unit and includes other sub components such as the
motors, encoders, solenoids and flow sensors.
(dwg version).
Assume for now that you have a really great laser, and these main
components are handled:
What other systems have to be on-line in order to have a cutting
operation?
Electrical
Two 110VAC 20 amp lines were run to operate ancillary equipment, a
220VAC 20 amp line services the laser power supply, a 220VAC 20 amp
line services the chiller outside of my house, and another 110VAC 15
amp line runs room lighting.
Ventilation
A ventilation system has yet to be installed in the work area. This
will be required to remove fumes and reduce smoke that will
contaiminate the optics inside the beam delivery system. The laser has
the capability to cut a number of different materials like wood and
plastic. Ventilation will be essential to remove the fumes produced by
these materials.
Gas Lines
The laser cutting system can use either oxygen or nitrogen depending
on the cutting application. This required that a couple tanks get
installed and I ended up mounting the tanks up off the wall. This is
to conserve floor space so I can cut larger sheets of metal. The
brackets came from the welding supplier. The plastic chameleon has a
couple magnets embedded in it for sticking to the tank.
A closeup of the regulators.
I mounted some solenoids to a board. Eventually I wil make housings
out of sheet metal.
The drivers for the solenoids are 110VAC regulated by relays. The relays take 12VDC in.
Support Arm
The laser head needs to be suspended about 48 inches away from the
nearest wall. Another design criteria was that it has to be able to
change the height of the laser along the z-axis. A CAD drawing was
put together, and I bought a pile of channel iron, angle iron, and
flat stock then went to work with my chopsaw. Note the lag bolts
attaching the angle iron to wall and floor.
Closeup of the wall bracket. There are four bolts and the top and
bottom of the bracket which work to clamp the support against the
channel iron.
Those outriggers werent part of the original design. The support arm
vibrated somewhat from left to right so they were added to create more
rigidity. Bolts extend off the outriggers and push against the
wall creating a very rigid system.
That summarizes the components required for a laser cutting
system. This next page takes a closer
look at the laser head used for this system. |
