Laser Cutter

What is a Laser Cutter?

Laser cutters create patterns and designs by cutting into materials. A powerful laser beam is the source that melts, burns, or vaporizes the material.

Essentially, laser cutting is a fabrication process that uses a thin, focused, laser beam to cut and etch materials into custom designs, patterns, and shapes as specified by a designer. This non-contact, thermal-based fabrication process is ideal for several materials, including wood, glass, paper, metal, plastic, and gemstone. It’s also capable of producing intricate parts without needing a custom-designed tool.

How Does Laser Cutting Work?

Laser cutting uses a high-power laser which is directed through optics and computer numerical control (CNC) to direct the beam or material. Typically, the process uses a motion control system to follow a CNC or G-code of the pattern that is to be cut onto the material. The focused laser beam burns, melts, vaporizes or is blown away by a jet of gas to leave a high-quality surface finished edge.

The laser beam is created by the stimulation of lasing materials through electrical discharges or lamps inside a closed container. The lasing material is amplified by being reflected internally via a partial mirror until its energy is enough for it to escape as a stream of coherent monochromatic light. This light is focused at the work area by mirrors or fibre optics that direct the beam through a lens which intensifies it.

At its narrowest point, a laser beam is typically under 0.0125 inches (0.32 mm) in diameter, but kerf widths as small as 0.004 inches (0.10mm) are possible depending on material thickness.

Where the laser cutting process needs to start anywhere other than the edge of the material, a piercing process is used, whereby a high-power pulsed laser makes a hole in the material, for example taking 5- 15 seconds to burn through a 0.5-inch-thick (13 mm) stainless steel sheet.

Laser cutting is not ideal for metals like aluminum and copper alloys because they have excellent heat- conductive and light-reflective properties, meaning they need powerful lasers.


Designing for Laser Cutting

Laser cutters work just like your regular inkjet printers. The machines have certain drivers that enable them to pick designs from the computer and to convert those designs into a readable format.

Several software packages can support the drivers of a laser cutter:
2D Design
• AutoCAD
• Inkscape
• Adobe Illustrator
• CorelDRAW

3D Design
• Autodesk Inventor
• SolidWorks
• Autodesk Fusion 360

Laser cutters have become handy tools for prototyping and manufacturing. They are being used:
• In rapid prototyping, because they allow designers to quickly and cheaply iterate on their designs before producing in large scale.
• In machine shops as well as in industrial manufacturing to cut large pieces of materials.
• In hardware companies to create prototypes.
• In education for prototyping/small projects.
• By artists and makers who want to bring to life their digital designs.

2D Design
3D design
metal

wood

Where is it used?

This technology can be used for a variety of applications, including cutting and scribing metals such as aluminium, stainless steel, mild steel and titanium. However, the process can also be used for the industrial cutting of plastic, wood, ceramics, wax, fabrics, and paper.

Laser cutting technologies are used across a range of industries, including aerospace and automotive applications as well as for cutting in hazardous environments, such as with nuclear decommissioning.

Metal
Cutting metal is one of the most common applications of laser cutting and is used on materials including stainless and mild steel, tungsten, nickel, brass and aluminium. Lasers are ideal for cutting metal as they provide clean cuts with a smooth finish.

Laser cut metal can be widely found for components and structural shapes including car bodies, mobile phone cases, engine frames or panel beams.

Wood
This cutting process can be used with wood, with MDF and birch plywood among the most common substances chosen as they can be manufactured in large sheets. The harder the wood, the greater the laser power required, with dense hardwoods needing more power than softer woods like balsa.

Wood is a favoured material as it provides strength without the cost of metals however, on the downside, wood can warp or bend over time, especially if placed under high strain or used in a damp environment. Aside from cutting, lasers are also frequently used to engrave wood, with CAD programs being used to create precise yet complex designs.

Advantages of a Laser Cutter:

Laser cutting offers a number of advantages over other processes, such as reduced contamination and easier workholding. Precision can also see improvements with lasers as the beam does not wear down during the cutting process, while materials are also less prone to warping with laser cutting. Lasers allow for the cutting of materials that may be difficult to cut using other methods.

Laser processes also provide consistently high levels of precision and accuracy with little room for human error, creating less wastage, lower energy use and subsequently lower costs.

Laser cutting can be used to etch complex designs on smaller parts while still leaving metal free of burrs and with a clean cut. There is also less workpiece contamination with laser cutting than with other processes.

advantages
major variety of laser cutting

Three Major Varieties of Laser Cutting

Flame/Reactive Rutting: The assist gas is oxygen, which is blown into the kerf at high pressure (up to six bar). The heated material (metal, in this case) reacts with the oxygen and begins to burn and to oxidize. This reaction expels more energy and assists the laser beam.

• Fusion Cutting/Melt and Blow: An inert gas (typically nitrogen) blows molten material out of the kerf, significantly reducing the power that is required. The material is first heated up until it reaches its melting point then the gas blows it out

• Remote Cutting: A high-intensity laser beam partially evaporates (ablates) the material, enabling thin sheets to be cut without the need for an assist gas.