I saw the competition and thought it would be fun to show off my system.
INTRODUCTION. 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 acheived 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.
Click here to see it cut
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.
Assume for now that you have a really great laser, and these main components are handled:
- Laser head and power supply
- Control unit
- CNC table and power supply.
- Cooling systems
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.
It was also useful to make boxes like this that have 110VAC entering into them and also had relays system that could be driven by TTL levels to run various appliances like 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.
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.
Here's a pic of the gas set up. Here is another.
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.
Here's the support.
Step 1: The Laser Head
- Average power range 10-100 watts.
- Peak effective power: 250 watts.
- Input power: 48 volts DC at 50 amps.
- Weight: 35 pounds.
- Cooling requirements: 2500 watts, water based.
- Original price: $27,000.
- The Coherent web site.
Control systems. The G-100 has a DB25 connector that supplies control and input modulation signals to the RF amplifier and supplies status information from the amplifier. This allows monitoring of the temperature, duty cycle, and supports digital control of the overall power output of the laser.