I found myself wishing I knew how to use a laser cutter one time too many.
Last weekend I was browsing field microscopes online for my Microthingy project, and I came across a clever tutorial for turning your smartphone into a microscope. The concept and construction are wonderfully simple: by taking a lens from a laser pointer and taping it to the phone camera you enhance its magnification capability, and with just a few pieces of plexiglass, plywood, a clicklight, a handful of bolts and screws you’ve got a suitable stage for positioning your phone and the sample you want to observe.
Intrigued I was, but I didn’t have appropriately sized pieces of plastic and wood at hand. This wasn’t the first time that I couldn’t easily come up with parts for DIY projects such as this one and I thought that this would be a good opportunity to learn how to use a laser cutter. It was just my luck that my local makerspace had a group training session on the same day for exactly that. So I went.
We learned how to create basic vector blueprints in CorelDRAW X8 and how to operate a VersaLASER® (VLS) 4.60 CO2 laser cutter and its software, the Universal Laser Systems (ULS) user interface, in order to cut and engrave into different materials*.
I got to make an acrylic tray, a tabbed plywood box, and also engraved a design into a drinking glass. In this post I’ll go into some steps we took to make these items and what I learned about laser cutting.
First we prepared the design file
A laser cutter uses a powerful laser beam to cut, engrave, and mark materials. We started off by creating our project design files which are basically instructions on what we wanted the laser cutter to do.
Both vector and bitmap images are acceptable; the shapes and lines of a vector image (or dots in the case of bitmap) in your imported design file are what the laser cutter uses to determine what to do and where. The images we worked with were in black and white / greyscale so that the darker parts would get a higher power burn and the lighter parts would get a lower power burn for engraving. We were taught that the laser cutter software recognises specific colours such as Red (#FF0000) and Blue (#0000FF) as instructions to “cut” or “mark” — another reason to work in greyscale — to avoid potential cutting errors.
Although we used CorelDRAW, any other design program with vector support such as Adobe Illustrator, Inkscape, or GIMP would have worked as an alternative.
We learned how to make and manipulate different shapes, set appropriate line widths and colours to create the blueprint for our acrylic tray from scratch, and for our plywood box we generated a blueprint from makercase.com and imported it to CorelDRAW for adjustments and adding our graphic of choice.
Then we configured the laser cutter
Once we were done with our designs, we loaded our CorelDRAW file into the laser cutter’s software a.k.a. the Universal Laser Systems (ULS) user interface. There, we had to give it details such as the type and thickness of the material the laser would be working with to ensure a proper cut or engraving. What I found interesting were the many specific material presets that were available as well as the laser’s cutting/engraving abilities and limitations with different materials or thicknesses (can engrave into stone and glass but not really cut through). For our three projects, we went with plastic/acrylic, birch plywood and soda lime glass.
A laser cutter requires some physical calibration as well. The starting location of the nozzle (from which the laser comes out) needs to be configured/set via the laser cutter UI and the nozzle needs to be maintained at a 2-inch minimum distance (focus height) from the materials’ surface.
Our laser cutter had a metal honeycomb platform in the bed that could be raised, lowered, or removed to accommodate the user’s need, and with the acrylic and plywood sheets it was enough to simply adjust the platform’s vertical height since they were fairly flat and thin. However, when we got to engraving our glasses, we took out the platform entirely to make way for the rotary setup and propped up the glass and its fixtures with a bubble level and wedge.
Each laser cutter at the workshop had its own exhaust and air assist which needed to be turned on before the laser cutter could its work. Apparently having good ventilation is quite important when laser cutting not only to reduce the risk of inhaling bad fumes, but also to keep smoke/particles from building up and interfering with the laser. As for the air assist, my understanding is that it allows for a cooler burn and also prevents the laser’s lens from overheating and cracking.
Cutting! Engraving! Making the things!
Here’s the laser cutter at work on my tabbed plywood box with finger joints as well as the finished product. We used a makercase.com generated blueprint and since I wanted something buggy I chose a Colorado potato beetle from ClipArt ETC and turned it into a vector to tidy it up.
To keep the sides of the box together after assembling it, I dabbed a small amount of wood glue on the edges of the tabs.
For the acrylic tray, I used a doodle I drew for my personal website’s homepage a while back. After the laser cut out the tray, we used a Formech Line Bender 500 to heat and soften the plastic along the marked lines so that we would be able to bend each of the tabs upwards. In the pictures below you’ll see little circles in each nook on the tray cutout; those are meant to help make the bending go more smoothly. On the line bender (right side pic), heat comes out of the vent between the two metal strips, so only that specific straight area gets softened for bending.
And finally, the drinking glass!
I drew a bunch of cartoon microbes in CorelDRAW for this one. Here’s the rotary tool at work – it turns the glass as the laser cutter engraves:
Neat Trick: Coating the glass with a bit of dish soap prior to etching helps dissipate heat and results in a smoother etch texture.