Laser Cutting

Overview

Laser cutting is a process that uses a high-power laser to cut through or mark the surface of materials. In order to have a file laser cut, you will need to drop off an Adobe Illustrator file and the material that we will be cutting this file from. Before dropping off a file, please read the information provided here in full, and be sure to allow for at least 48hrs for job completion.

Equipment

The RP Centre has two CO2 laser cutters:

  • Trotec Speedy 500, 120 watt CO2 Laser cutter with a 48" x 27" size bed
  • Universal, 150watt CO2 Laser cutter with a 32” x 18” size bed

Pricing

Laser cutting is charged at $1/min +$6 set-up fee per visit

Materials

You will need to provide your own materials for laser cutting. We are able to work with a wide range of materials up to a thickness of ¼”. This includes: Acrylic, Plywood, Fabric, Leather, Cardboard, Paper.

materials

You can find most of these materials available for sale in the OCAD U Plastic Shop, the Wood Shop and at local art supply stores.

Note that for safety reasons there are some materials that are unable cut:

  • Acrylonitrile butadiene styrene (ABS)
  • Double Wall Corrugated Cardboard
  • Foam-core/Polystyrene presentation board
  • Pleather/fake leather
  • Vinyl
  • Polycarbonate/Lexan
  • PVC (Polyvinyl Chloride)
  • Styrene

If you are looking to work with a material not listed here, please bring in a sample to discuss with an RP staff member.

Preparing your files

In order to run a laser cutting job, you will need to provide a vector based file. These can be prepared in Auto CAD, Corel Draw, Inkscape or Adobe Illustrator. We ask that you save your file as an Adobe Illustrator file before dropping it off in the RP Centre. If you have any questions about this, please ask a staff member.

Here is an Adobe Illustrator template that you can use to get started: LaserCuttingTemplate.ai

If you need help getting started with Adobe Illustrator for the first time, take a look at these Online Illustrator Tutorials: https://helpx.adobe.com/illustrator/tutorials.html

We also recommend Lynda tutorials available to OCAD students here:
https://www.ocadu.ca/services/it/wireless-and-web-services/lynda.htm

5 steps to successful laser cutting

1. Match the artboard in your file to the dimensions of the material that you are bringing in. This ensures that your artwork will fit on your material.

When planning your work, keep in mind that your material must be able to fit on our machines. Our machines have a maximum bed size of: 48" x 27" and 32” x 18”.

STEP 1

Note: Because our machines work in inches, we work in inches. You can switch the units of your file when you first open a new file, or by right-clicking (or control-clicking) on the rulers.

2.Set the colour mode of your file to RGB. This can be done in the document preferences when you first open a new file or under the “File” menu.

STEP 2

Once in RGB-mode, you can find the basic RGB colour swatch Select Swatch Library Menu -> Default Swatches -> Art & Illustration

3. Indicate whether you are looking to cut or engrave your work using the guidelines below:

STEP 4

All cut lines need to be indicated using Red, Blue and Green lines with a stroke weight of .01pt

The laser will interpret the colours as ordered cut lines working from the inside out. Starting with Red (RGB: 255, 0, 0) followed by Blue (RGB 0,0,255), and finally Green (RGB 0,255,0). All interior cuts should be cut first and therefore should be red, with any further cuts being Blue, and the final exterior cuts being Green.

Rastering (or engraving) is achieved by using black lines and fills in your file. Different depths of rastering can be achieved by using several tones of grey. Black will always be rastered the deepest, with White not being touched. The darkness of the Grey tone will determine how deep the raster will be. Keep in mind that in order to raster, the laser passes over an area hundreds of times removing one beam width per pass. This means that very large rastering jobs can take a long time and as a result be very expensive! Use this technique wisely. Also note, that while we can do deep or shallow engraving, we cannot engrave to a specific depth.

Linear engraving is a fine-line engraving that is achieved by running a low power cut-line. This is indicated in your file by having a black line .1pt.

Donut example

4. If you are using text in your file, you will need to change it to outlines. We will most likely not have the font that you are working with, by converting your text to outlines you ensure that the text looks the way you intend it to. You can find the “Change to outlines” command in the “Type” drop-down menu.

STEP 5

5. Don’t waste material! Try to cluster pieces that you are having cut close together, in one area of your material. Pieces only need 1/8” between them. By laying out your pieces closely together, you will also save on the material that you need to buy.

Laser cutting tips and tricks

Cutting out text

Using a stencil font will prevent the middle islands of some letters to fall out when laser cut. If you don’t use a stencil font, the text can be difficult to read. You may also want to open up the kerning of the text for better legibility.

text example

Small details / cut widths:

We recommend that minimum cut widths be no smaller than 1/16”. We can go smaller but things can get quite fragile and we cannot guarantee it will work.

Clean vectors:

Before dropping off your work check that your vector lines are joined and that there are no overlapping lines in your file. Also check that there are no vector paths hidden behind white shape fills.

Kerf:

Because laser cutting is a heat based process, some material vaporizes during cutting which results in some space being created on either side of the laser beam- this space is called the kerf. If you are working on something that needs to be of a very specific size (ie. Finger joints, inlays etc.) it is important to take into consideration how the laser's kerf will affect the final result.

The exact size of the laser kerf depends on many variables, including:

  • The material you are cutting
  • The thickness of the material you are cutting through
  • The wear of the gantry that moves the laser head around
  • The power of the laser you are cutting with
  • The strength of the air assist
  • The direction of the woodgrain, if you are cutting wood

If exact fit is crucial, we recommend doing a fit test before you cut your final work.

It is also worth mentioning that laser cutters will cut materials at a very slight angle- wider at the top and narrower towards the bottom. This is generally not very noticeable, but can affect some applications particularly when working with thicker material.

kerf-illustration

Working with Jpegs:

It is possible to raster a jpg that is pasted in your illustrator file so long as you ensure that you have embedded it. This is done in the options that appear when you are saving your file. Without embedding the image, we will be unable to see it.

Additional resources

Joyoflasercutting.com

Lynda.com