The Laser Cutting Machine

Paul Haeberli

Nov 1996

Horiz Bar

Laser light may be used to cut and score a wide variety of materials. With a laser cutting machine like this, paper and plastic can easily be scored and cut very precisely. Even plywood up to 1/4" thick can be cut on this small machine. Larger industrial machines can cut metal as well. Typically the plotting rate and power of the laser are modulated to select various levels of scoring and cutting.

This particular machine is used primarily to create architectural models out of plastic. It has a cutting area of 3 feet by 2 feet, but larger machines have cutting areas of 8 feet by 4 feet. The major components are the gas tanks, the laser plotter itself, and the controller.

These tanks provide nitrogen gas that is used to limit the burn rate when flamable materials like paper are being cut.

A program on this PC reads a user's AutoCad DXF file from a floppy disk and controls the laser cutter. Profiles for the current material being cut are set by the operator here.

The laser plotter is a mechanical 2D positioning mechanism driven by motors. The laser is mounted in the back.

Small mirrors are used to guide light from the laser to a particular location on the material.

The base of the cutting area is made from a honeycomb material to let the laser light pass through. This has to be replaced periodically.

Scoring and multiple cutting layers are indicated by labeling the layers 1S, 2C and 3C in the input DXF file. The lines to be scored are given by the layer labeled 1S. All scoring is done before cutting is started. The width of the cuts and scores is approximately 0.009" on this machine.

Any number of cutting layers are given by layers 2C, 3C, etc. These are cut in numerical order. Multiple cut passes are needed for parts that have holes in them. First the holes are cut, then the shape of the piece is cut. This avoids problems that may occur due to parts shifting after being cut. A sample DXF file is given here for your perusal.

I've completed a three projects so far

A simple folded shape - laser scoring mylar and paper
A 3D surface function - cutting and scoring cardboard
A short production run - making a kit for distribution

This laser cutting work was performed at Terziev Studios in San Francisco, California. Many thanks to Sergé, Ian, and Zdravko for their help.