In this tutorial, I will be using a Trotec laser cutter and Corel Draw to etch a vector image I made onto a small sheet of acrylic.
I will briefly discuss the material and vector that I chose before I go into more depth about the printer and printing software itself. Note that this is an overview for this particular kind of laser cutter; there are many kinds of laser cutters and software available. This should give you a general idea of what the process is like. Chances are if there's a laser cutter available to you you'll have to do a bit of research before you can use it.
WARNING: this is a basic intro to laser cutting as a concept. Laser cutters can be damaged and can be dangerous if not used correctly. It is highly recommended that you receive formalized training before using one.
More information about the Pittsburgh TechShop can be found at http://techshop.ws/
I made it at TechShop!
Step 1: Choose Your Image
Time: from 15 minutes to 3 hours
[Note: time varies greatly based on factors such as familiarity with the machine, raw material, complexity of input file, and experimentation with laser settings]
-Laser cutter (Trotec for this tutorial)
-Vector software (e.g. Corel Draw, Adobe Illustrator)
-Laser cutter driver software (Job Control)
-Vector file of your design
-Sheet of raw material (acrylic)
[As a rule of thumb, you should bring more material than you plan to use in your final product. It is common to get the settings or placement wrong when working with an unfamiliar material]
After assembling your materials, the first thing you should do is decide what you'd like to etch. Trotec laser cutters can take both raster and vector data.
Raster images are composed of a series of pixels. If you choose a raster formatted image, like a .png, .jpg, or .gif, the laser will make deeper marks on darker pixels and lighter marks on lighter pixels.
Vector images are composed of equations of lines, curves, and other relavent data. You can make them with programs such as Adobe Illustrator or Corel Draw. If you choose a vector image, the laser will follow the lines described by your inputed file. The strength of the laser will depend on how dark your lines are on a white to black scale.
For this Instructable, I took inspiration from a character my friend made for a game and I made a quick vector design in Illustrator for the character's Business Crab Enterprises.
Step 2: Materials to Choose From
Always check to make sure that that you want to cut can be processed by the laser cutter; there are some materials that just won't cut, but others will melt, produce gas that can ruin the laser's lens, or produce toxic gas if cut. Below are the materials approved for the Trotec. Again, not all laser cutters are the same. Please check that your material is okay for your particular cutter before cutting anything.
Here are some materials that CANNOT be cut by a laser cutter and why:
- Vinyl, PVC, Foam Core, Polymer Clay: produces Hydrogen Chloride gas
- ABS: produces Hydrogen Cyanide gas
- Styrofoam: can start a fire
- Metal, mirror: can reflect laser back into internals of machine
- Polycarbonate, PETG: Does not cut
- Fiberglass: this one varies; check with the machine manufacturers or owners
Step 3: Choose Your Material
Please note that if you are unfamiliar with laser cutting, have not worked with your chosen material before, or are using a particularly expensive or difficult to acquire material you should test your laser settings on a scrap piece of that material before you start your final project. It is very easy to choose the wrong settings and ruin a piece of raw material.
Step 4: Laser Cutter: Basic Information
Top lid: You open the door on top of the laser cutter to place your piece. You can look through the lid to watch the progress of the cut.
Power switch: On the Trotec, the power switch is on the back of the machine. Make sure it is turned on before attempting to use the machine.
Control panel: This is where you set the laser position, receive error warnings, and pause the cut. We will go into this in more detail soon.
Ventilation: The cutting process produces gas, particulate, and usually a small amount of fire from the heat of the laser. The ventilation system is there to sweep away any gas produced and to keep the fire low. (Note: the fire produced by the laser should always be less than a centimeter in size. If your piece catches fire, stop the job IMMEDIATELY by lifting the lid)
Head: This contains the lens that focuses and reflects the laser onto your surface. It moves in a two dimensional plane according to the file you give the printer to cut the image into your material.
Support grid: This is the platform onto which you place your material. This honeycomb aluminum grid will hold up your material while allowing for proper ventilation.
Side Rulers: The bed of the laser cutter has rulers along the edges. You will be using these to compare the dimensions of your piece with your input file.
Front door: This door allows you to access the area under the support grid. It should be kept clean and should never be used as a storage space.
Step 5: The Laser Cutter Control Panel
The black arrows are for moving the support bed up and down. Be careful when using these buttons--moving the bed too far up can make it collide with the laser head and can damage the machine.
Step 6: Placing Your Piece
If the laser head is too close to the bed for you to slide your piece underneath, use the up/down arrows to move the tray down first.
Step 7: Adjusting the Laser's Focus (Part 1)
The laser cutter should come with a small metal tool (pictured below). It two feet on the bottom and a small square on the back. Identify this piece or ask for the equivalent for the laser cutter that you are using.
Step 8: Adjusting the Laser's Focus (Part 2)
Step 9: Adjusting the Laser's Focus (Part 3)
Step 10: Close the Lid
Step 11: Connecting to the Laser Cutter
At the Tech Shop, there is a dedicated computer wired to each laser cutter. It has all of the proper software to operate the laser cutter installed: Corel Draw, Adobe Illustrator, and Job Control. I will not be going into detail as to how to set up a station like this; if you are in a position where you need to install software or connect to the cutter for the first time, I would advise you to do some research or ask someone who is qualified on the subject.
Step 12: Software Setup: Using Corel Draw (Or Adobe Illustrator)
Open Corel Draw. If your file was made in Corel Draw, open it. If it was made in Illustrator, first create a new RGB file and import it. Both options can be found under the "File" menu.
Step 13: Software Setup: Lining Up Your Piece
You should also use the rulers to determine the size of your piece; the selection arrow in the upper left hand corner can be used to both move and resize your design. [If you are unfamiliar with CorelDraw software, I would recommend viewing a basic tutorial]
Step 14: Software Setup: Line Weight and Colors
To change the color and weight of your lines, begin by selecting a line that you would like to change. In my example, I want the outer rectangle to be cut out of the material but I want the rest of the design to be etched. I therefore select the outer rectangle.
In the lower right hand corner of the window there should be a set of buttons (highlighted in the picture below). If you click on the lower of the two boxes, a menu like the one shown below should pop up. Click on the color box and select "RGB Red". Click on the width dropdown and select "hairline". Click the "Ok" button when you are done. Repeat this for any item you wish to cut out or change the width of.
Step 15: Software Setup: Sending Your File to Job Control (Part 1)
Step 16: Software Setup: Sending Your File to Job Control (Part 2)
In the "Size Settings" section of the menu, specify the width and height of your material.
In the "Material Settings" section, select the material type and subtype from the dropdown. I chose "Plastic" and "Acrylic".
When you are finished, click on the button marked "JC". This will send the file, placement, and materials preferences to the laser cutter program called Job Control. Close out of this menu, press "Apply" and "Print" in the Print Menu, and switch over to the Job Control program. (If Job Control isn't open, open it manually.)
Step 17: Job Control: Placing Your Image
Step 18: Job Control: Printing Your Image
The rulers in this window correspond with the rulers on the edges of the laser cutting bed. In order to save space and to not waste material, use these rulers as guides to get your material and file lined up. My material is an irregular shape; I therefore positioned my file so that it wouldn't run off the edge of the material.
When you are ready to print, click the "Play" button in the lower right hand corner.
Step 19: The Cutting Process: Waiting, Watching, and Material Removal
Keep an eye on the cutting process. That being said, do not look straight at the laser beam. It can damage your vision.
The cutting process can take anywhere from less than a minute to an hour or more. Often, you will need to do more than one pass on the laser cutter for the cut to go all the way through the material. If the design is intricate or the material demands a slower cut, be sure to allocate enough time for the cut to finish. Again, it is highly recommended that you test the laser settings on a piece of scrap material before you start a bigger project.
The laser cutter should beep when it is done cutting. Lift the lid and pull out your material. Pop out any extra pieces cut out by the laser. You should also remove any remaining scrap material from the laser bed.
Step 20: Tada!
You may not have gotten the effect you wanted--it is common in laser cutting to not turn out the way you expected the first time. If lines are skipped in the cutting sequence or parts of your piece do not turn out quite right, adjust your settings in Corel Draw, Print Settings, or Job Control. It may take a few tries to get it right.