Frequently Asked Questions
Frequently Asked Questions
This is an old revision of the document!
The laser cutter is a RedSail model CM1080; it has a bed area of 100cm x 80cm (1000mm x 800mm) and uses a 80W CO2 laser tube. It is capable of both cutting (with vector shapes) and engraving (with raster images), both of which may be used together in a single job.
The Laser Cutter Committee oversees its usage and ensures correct maintenance. If you have any questions or concerns, please contact a member of the LCC.
The laser cutter is a piece of industrial machinery. The laser cutter is not a printer, it is not an appliance, and it is not a peripheral. It must be treated as such; a potentially very dangerous device. You must remain in within 1m of the Emergency Stop button at all times. It must never be left unattended, even for a minute. Fires in laser cutters are very common, and given that we are in an old wooden building, any fire could quickly engulf the entire building, and the operator must be ready at all times to extinguish a fire as soon as it occurs.
We know of four people who have had to essentially replace their laser cutting machine because it caught on fire unattended. One person had their entire shop burned down because they cut acrylic and left it.
There is a zero-tolerance policy around leaving the laser cutter unattended while in operation, and laser cutter privileges will be revoked immediately.
The single most important aspect of safety when it comes to machinery is respecting the machine. This means taking care of it, being careful in your configuration, testing, and usage, ensuring proper maintenance happens, and keeping a close vigil over its operation. Careless behaviour causes tools to deteriorate fast, which is the primary cause of safety issues.
Laser cutters work by heating the material to the point of burning or vapourization. Your job can change in seconds with the accumulation of energy (heat) in your material. Always monitor your lasing job! Never leave the laser cutter room while your job is running.
At 80W, this is considered a Class 4 laser device - the most dangerous rating possible. It is in fact 160x the minimum rating for a Class 4 device. This is very, very powerful and dangerous.
To make matters worse, CO2 lasers emit completely invisible IR (infrared) laser beams at 10,640nm. There is no way to know where the beam itself nor any reflections are going. The only thing you can do is completely avoid any possibility that the laser energy will leave the laser cutter.
At 80W, it will instantly vaporize the cornea, lens, and/or retina of your eye. You will instantly and permanently lose your eyesight - and while it scars over it will be complete agony. It will boil your eyeball. According to Wikipedia, “A pop or click noise emanating from the eyeball may be the only indication that retinal damage has occurred i.e. the retina was heated to over 100°C resulting in localized explosive boiling”. Even indirect exposure to the laser beam (or a scattered part of it) can result in blindness.
To reiterate, this laser cutter is 160 times as powerful as the maximum safety-class that is worth differentiating between; well and truly into the realm of lethality if mistreated.
In short, this is a very dangerous device and must be treated with utmost respect and care. It is absolutely the most dangerous tool most people will ever use.
We have special safety glasses that are specifically rated for use with CO2 lasers. They are completely transparent to visible light, but are opaque to the band of infrared light that the laser cutter operates on. Do not use any other safety glasses with the laser cutter, as they will not provide any protection.
It is important that the safety glasses remain functional, so please be very careful with their care and handling. Always replace them in their protective cases, and never put them lenses-down. These are not typical, cheap safety glasses, and must be ordered online (and still aren't cheap!).
Small flare-ups while cutting material is common, and for flare-ups that don't self-extinguish quickly, the spray bottle is the first line of defense.
If the spray bottle is insufficient for extinguishing a fire, the fire extinguisher should be used.
It should only be used as a last resort however, as its use will destroy the expensive ($300+) mirrors and lens in the laser cutter. Don't let the price deter you from using it when necessary though - it's better to pay for new mirrors than to burn down the entire laser cutter, building, VHS, and all our neighbours!
You will never be in trouble for using the fire extinguisher, and will not be responsible for any replacement/repair costs. Use the fire extinguisher when necessary.
The software used for interfacing to the laser cutter is called EasyCut 5.3, which is a rebranded and pre-configured version of LaserCut 5.3. It is a rather dated program, but is usable. Because its editing capabilities are rather poor, it is recommended that EasyCut is only used for the final steps of setting up the work for the laser cutter, and running the job itself.
Corel Draw is available on the laser cutter PC, and is very useful for converting between file formats. Do not use the laser cutter PC for design work however, as that will stop others from being able to use the laser cutter. The laser cutter PC is only to be used for converting and running jobs on the laser cutter. Use your own laptop to create designs, and load/convert them on the laser cutter PC via USB key.
EasyCut takes primarily .ai (Adobe Illustrator) and .dxf (AutoCAD, Inkscape, SolidWorks, Corel Draw). AI files are preferred as they preserve curves better, but in practice DXF is very usable.
EasyCut takes BMP/JPG/PNG images. They must be 1-bit (black & white dithered, not greyscale), and will need to be scaled appropriately when imported into EasyCut.
Corel Draw is a good choice for creating files for use on the laser cutter, or converting existing files into formats that can be used, due to its wide variety of import and export formats. Adobe Illustrator may also be used, but it has limited capability for exporting to the older versions of file formats that EasyCut requires.
The most time-consuming, challenging, and thus error-prone step of preparing a file for the laser cutter is setting up the order and settings for the various parts of the job. In EasyCut these are controlled on a per-layer basis, where an unique colour is considered to be a layer (i.e. all parts that are red have the same settings and are cut together, and all parts that are blue may have different settings and also are cut together). The order is specified by the order the layers appear in a list (the top layer will cut first), and may be re-arranged as required. Generally when you're setting up a job, you will want to cut the smaller and more intricate/interior parts first, progressively working up to the larger cuts, and ending with the outline of the work. You will quickly get a grasp on what this means and how to do identify what parts of a given job must be cut when.
Some experimentation will be required to get the desired results. Refer to the materials and settings chart for reasonable starting points.
Always bring extra scrap material with you that has identical properties (type, thickness, colour, etc) to what you want to finally lase. Use this scrap to test and verify that the laser cutter, your material, and your designs setup are behaving as you expect.
Flare-ups happen frequently when using a laser cutter; it's simply the nature of the tool. Most flare-ups will self-extinguish as soon as the laser beam (the heat source) has moved away from the area being cut, or if the laser is turned off (by completing the cutting job, the Stop or Pause buttons being pressed, or by pressing the Emergency Stop button).
If a flare-up has been going for more than a few seconds, or shows any signs at all of fully igniting or burning through the material, immediate action must be taken to stop the fire. Your material/work piece is lost at this point - act quickly and do not hesitate.
Questions may be directed to the Laser Cutter Committee.