CNC Laser Cutters would you like to know about them and how they work, well Look no further. In this blog below you will be able to get enough information to know how they work and this information will help you on your quest to either buying one for yourself or learning more about the industry.
What is a Laser?
A laser is a device that emits a light through optical amplification and this is based on the stimulated emission of electromagnetic radiation. Laser the word is really created by the acronym
Light – Amplification – Stimulated by – Emission of – Radiation
Lasers are constructed from 3 principal parts.
- Energy Source – Original Light Source (optical pump)
- Gain Medium – A Gas solid or Liquid that creates identical photons
- 2 ore more mirrors that form an optical resonator
An original light energy source is introduced to a Gain Medium. This can take the form of a Helical lamp that is wrapped around the gain medium. A 100% reflective mirror is placed on one side of the gain medium and a 99% reflective mirror on the other. The light source sends photons into the gain medium and these photons stimulate the atoms in the gain medium material which result in photon emissions in the gain medium. These photons gain momentum by bouncing backward and forward between the mirrors. However, not all photons some escape through the side of the medium. When the photons escape through the 99% reflective surface and a laser beam is created.
CNC Laser Cutters use this beam to cut the work piece.
CNC Laser Cutters use 3 main types of laser
- CO2 Laser – Suitable for cutting boring and Engraving
- Nd Neodymium – Used for boring and where high energy and low repetition is needed.
- Nd YAG Neodymium Yttrium- Alluminium Garnet – These are high powered lasers but used for higher repetition.
CNC Laser Cutters – Laser Cutting Methods
There are various laser cutting methods. So you would choose which one you need according the material you were using. Here are some examples below
A high powered beam is focused on the surface of the material and heats it until the material vaporised. This is used for material that doesn’t melt for example wood, carbon or thermoset plastics.
Melt and Blow
Melt and blow or fusion cutting uses a high pressure gas to blow the molten material out of the cutting zone or kerf. This method is mainly used for cutting metals.
Thermal Stress Cracking
Some materials are quite brittle and are susceptible to thermal fracture. This property is used in this method. When the material is heating, thermal expansion will cause stress fractures and the cracks can be guided by moving the beam. This is usually used for cutting glass.
Stealth dicing of silicon wafers
This method uses an ultra-thin laser beam with a wave length of about 1064nm (Nano metres) and this is then used to cut the material for silicon chips.
CNC Laser Cutters – Machine configurations
The main configurations for cutting machines are;-
Moving material lasers – These have a stationary laser head and the material is moved under the laser head.
Hybrid lasers – This configuration has a bed that moves on 1 axis usually x axis
You can see here that the table or work surface is set and the laser head moves over the work piece in an X or Y axis. This is the fastest type of configuration for cutting and this is great for cutting thin materials and so these machines have to be designed to take into account the material distance from the cutting head. Adaptive optics methods are used to overcome this issue. So 5 and 6 axis machines allow the cutting of formed materials. There are various methods of orienting laser beam on a formed or shaped material to maintain the correct focal distance that takes into consideration nozzle stand-off (Adaptive Optics).
Once you know what you are going to be making you can choose what configuration, you will need you will be able to choose from a range of CNC Laser Cutters the one that you need . However, many desktop CNC machines these days may have a multi-tool option, this is where you can interchange between CNC Routers and CNC Laser Cutters etc. The above information gives you some insight into the configuration of the laser cutting tool itself when deciding how to create your design.
There you are CNC Laser Cutters. So this blog will help you to buy the CNC Laser Cutters or cutter that you need.