L.A.S.E.R. Cutter / Engraver
Safety and Basic Usage
Welcome to Robot Garden’s SBU for the Light Amplification by Stimulated Emissions of Radiation (L.A.S.E.R) cutter / engraver. This SBU covers the safety concerns and procedures for operating the LASER device with a brief tutorial on cutting and engraving. Links will be provided for more detailed study in engraving and cutting with the system, while basic operations and material usage is included herein.
There are many available resources online for laser cutting and engraving. A very good site is Pololu Robotics and Electronics. They present material in handling material and operating a Laser cutter/engraver and we’ve attached the link below. Take note of the following two sections; Materials we can cut and Materials we cannot cut. These are important.
Links of Use:
Full Spectrum Laser 40W CO2 – www.fslaser.com
Pololu’s Laser Cutting Materials (do’s and don’ts) – www.pololu.com/docs/0J24/3
We can laser cut plastics, woods, rubbers, foams, papers as long as they do not contain chlorine. Depending on the material, there is usually no limit to the thinnest sheet we can cut, and the thickest sheet we can cut is typically 1" (24 mm).
Materials we can laser cut
- ABS (acrylonitrile butadiene styrene)
- Acrylic (also known as Plexiglas, Lucite, PMMA)
- Delrin (POM, acetal)
- High density polyethylene (HDPE) – melts badly
- Kapton tape (Polyimide)
- Mylar (polyester)
- Nylon – melts badly
- PETG (polyethylene terephthalate glycol)
- Polyethylene (PE) – melts badly
- Polypropylene (PP) – melts somewhat
- Two-tone acrylic – top color different than core material, usually for custom instrumentation panels, signs, and plaques.
- Depron foam – often used for RC planes.
- Gator foam – foam core gets burned and eaten away compared to the top and bottom hard shell.
- Cloths (leather, suede, felt, hemp, cotton)
- Magnetic sheets
- Rubbers (only if they do not contain chlorine)
- Teflon (PTFE, Polytetrafluoroethylene)
- Woods (MDF, balsa, birch, poplar, red oak, cherry, holly, etc.)
Materials we cannot laser cut
We do not or cannot cut the following materials:
- Metals – Including Foils.
- Polycarbonate (PC, Lexan) – Lexan produces Fumes and Melts.
- Any material containing chlorine
- PVC (Cintra) – contains chlorine
- Vinyl – contains chlorine
- Glass – we can engrave glass, but we cannot cut it.
- Printed circuit board (FR4 and other material types)
- Carbon fiber
- High-density polyethylene (HDPE) - HDPE of any thickness melts badly when laser cut.
Part 1: Safety – From the Full Spectrum Laser User’s Manual
Please carefully read all instructions before attempting to operate the laser. Never operate or test the laser without the water pump activated or with anything other than pure distilled water as a coolant. Never attempt to operate the laser with the lid open or attempt to override the magnetic lid interlock switch. Please inspect the laser tube carefully for any shipping damage and contact us immediately via email if there are any issues. Know your marshals.
The output of the CO2 engraving laser is fully contained in a Class 1 enclosure during normal operation. The laser cabinet has a safety interlock switch that deactivates the laser if the door is opened during operation, and no special precautions are necessary to operate the high power laser safely. However, the output beam of the Alignment Laser (visible red diode laser) is accessible to the operator during normal operation, giving the total system an overall rating of Class 3R. While this device employs the same technology as a handheld laser pointer, it is potentially hazardous if its beam is directed into the eye.
General Operation Precautions
The laser operator should observe the following:
- NEVER operate the machine with any of the panels removed. Be aware that removal of any portion of the cabinet will expose a Class 4 laser system and greatly increase the risk of injury and/or fire. PERSONAL INJURY AND FIRE RISKS ARE ESPECIALLY PRONOUNCED IF THE MACHINE IS OPERATED WITH THE BOTTOM PANEL REMOVED. Remember that the CO2 laser beam is invisible!
- NEVER engrave or cut any material containing PVC or vinyl. These materials (along with other chlorine/chloride containing materials) produce a corrosive vapor that is extremely harmful to humans and will destroy your machine. Your warranty will be void if your machine is damaged by corrosion from engraving or cutting PVC or vinyl.
- NEVER engrave or cut any unknown material. The vaporization/melting of many materials, including but not limited to PVC and polycarbonates, can give off hazardous fumes. Please refer to the MSDS sheet from the material manufacturer to determine the response of any work material to extreme heat (burning/fire hazard).
- NEVER operate your machine unattended. There is a significant risk of fire if the machine is set improperly, or if the machine should experience a mechanical or electrical failure while operating.
- ALWAYS use the air assist, especially while vector cutting. Vector cutting movements are relatively slow and apply an extremely large amount of heat to the work piece. This buildup of heat can cause a significant fire risk.
- DO NOT disassemble the machine or remove any of its protective covers while the unit is plugged in.
- DO NOT defeat the door interlock.
- DO NOT look into the beam of the Alignment Laser (visible red diode laser)
- DO NOT operate the Alignment Laser without the focus lens in place. The unfocused beam can be reflected out of the chassis.
- NEVER operate the machine without a properly operating ventilation system. Most materials produce an irritating smoke when engraved. Some materials, including but not limited to paint, varnish, composition board and plastics, produce compounds that can be harmful if concentrated.
The AC input power to the Full Spectrum HL40-5g is potentially lethal and is located on the far right within the cabinet.
- DO NOT open any of the machine’s access panels while the unit is plugged in. Opening a panel may expose the operator to the unit’s AC input power.
- DO NOT make or break any electrical connections to the system while the unit is turned on.
- DO NOT access the electronics area with hands or tools unless the unit is disconnected from power.
The power supply is capable of outputting DC 20,000V at up to 20mA—always make sure to give the supply capacitors adequate time to discharge before accessing the electronics area. This power is also provided to the discharge terminals on the laser tube itself. Your laser shipped with silicone terminal covers that prevent access to bare wiring—notify Full Spectrum Laser support and immediately cease operations if these covers ever slip and expose bare wire. 
Laser cutting and engraving systems represent a significant fire hazard due to the extremely high temperatures generated by the laser beam. While the objective of most cutting and engraving operations is to vaporize material without burning, most materials capable of being cut or engraved are inherently combustible and can easily ignite. Usually this is a small flame of burning material issuing from the cut zone which self-extinguishes due to the air assist or de-powering of the beam. However, it is possible for the flame to propagate and set fire to the machine and threaten its surroundings.
Experience shows that vector cutting with the laser has the most potential to create an open flame. Acrylic in all its different forms has been shown to be especially flammable when vector cutting with the laser. Please also be aware that stacking materials (especially organic materials such as paper) can lead to increased risk of flame propagation or work piece ignition.
Please read the following warnings and recommendations and follow them closely at all times!
- NEVER leave the laser system unattended during operation.
- KEEP the area around the machine clean and free of clutter, combustible materials, explosives, or volatile solvents such as acetone, alcohol, or gasoline.
- ALWAYS keep a properly maintained and inspected fire extinguisher on hand. Full Spectrum recommends a Halogen fire extinguisher or a multi-purpose dry chemical fire extinguisher. Halogen extinguishers are more expensive than a dry chemical, but offer certain advantages should you ever need to use an extinguisher. The Halogen extinguisher discharges a clean, easily removable substance that is not harmful to the mechanics or wiring of the laser system. The dry chemical extinguisher discharges a sticky, corrosive powder that is very difficult to clean up.
- ALWAYS use air assist when vector cutting.
- Be Careful when vector cutting. Many materials have the potential to burst suddenly into flames – even materials that may be very familiar to the user. Always monitor the machine when it is operating.
- KEEP The Laser System Clean – A buildup of cutting and engraving residue and debris is dangerous and can create a fire hazard. Keep your laser system clean and free of debris. Regularly remove the cutting grid to clean any small pieces that have gotten stuck or fallen through.
Robot Garden Specific Laser Usage
- When in doubt, as a marshal.
- Understand the LASER and read the user’s manual thoroughly.
- Ensure the exhaust fan is running properly.
- Ensure that the water pump is functioning and water is flowing through the unit.
- Ensure that the power plugs and surge protector are properly fitted and power is flowing to the unit.
- Twist the E-stop to start the unit.
- Ensure the LCD displays the boot parameters and IP of the unit.
- Press the “Home” button to home the laser mirror carriage.
- The laser should be aligned, however, if you feel you wish to check it, get a Marshal to walk you through the procedure.
- Ensure that you have will be cutting/engraving material approved for the system.
- Ensure the PC is running and that the RetinaEngrave or other proper software is running and you have a good connection to the cutter. If you have problems, get a Marshal.
- Load your work into RetinaEngrave.
- Ensure your material will fit within the cutter dimensions of the system. We have a 20”x12” cutting/engraving perimeter.
- Engrave or cut your material. DO NOT leave the system while it is running. You will see flashes and or flame given certain materials and how you are using the system, this is OK, but if it gets out of hand, hit the E-STOP and if need be, get the extinguisher and a Marshal.
NOTES FROM SBU COURSE: Additional Consideration While Working at Robot Garden.