For my first project on the laser, I decided to make coasters, like for beverages. Only, these wouldn’t be regular coasters: they would connect together to form a trivet, puzzle, or whatever the user wants them to be. The idea was to create something simple yet multifunctional that will also be a good test of the laser’s etching capabilities. I started with a few simple drawings to determine the patterns I’d be etching and how they would connect together. Initially I wanted to go with a tongue and groove mechanism.
I had a ton of left over pine from my last project (the failed birdhouses), so I chose to reuse this material that I already have over buying a new piece of wood or acrylic. This posed a few challenges:
- I had to cut the wood to half its thickness. The board were about 1″ thick when I bought them. Doing this was going to be tough because it would require splitting it.
- Cutting out the coasters with the laser would be impossible because of the thickness the tongue and groove mechanism would require. I’d be on the saws again for this project.
The bandsaw plus some fancy jig work seemed like the best tools for this job, despite the shop staff looking at me like I was crazy for wanting to do it. I selected one of the birdhouse roofs and needed to separate the two pieces that were stuck together with wood glue. I used the bandsaw for this too.
Once the two glued together pieces were separated, it was time to split the largest piece. I built my jig using the bandsaw’s fence and a long, thick piece of wood from the scrap pile.
I clamped down the piece of wood and used one of the shops “push snakes” to push the piece of wood I was cutting through the bandsaw blade.
As expected, the cut wasn’t perfect and the resulting pieces were rather lumpy. Nothing a good sanding couldn’t fix.
One piece was more than 1/2″ thick, but close enough. I focused on evening out that one with the belt sander. I sanded the front and back, as well as the edges of the piece until it was smooth and flat throughout (or as much as it could be).
Realizing that the remaining piece gave me a decently thin slice of wood for future projects, I decided to sand it down as well. This was more difficult because it kept slipping through the gap between the sanding bed and the sander belt itself, but eventually I was able to smooth it out as well.
Back at my desk I completed some additional sanding by hand to further smooth out the edges and remove any splinters.
Next I made my drawings of the coasters in Illustrator. I was learning the program from scratch, so this part took a while.
It was about this time that I started talking to one of my Intro to Fab classmates. She had created a beautiful box for her Arduino using laser cut wood that fit together like puzzle pieces. I had already been contemplating ways to do more than just etch designs into my coasters, but after seeing what my classmate made I had an epiphany: why not shelve my tongue and groove idea for now and instead use the extra thin piece of wood I had left over to create puzzle piece coasters? It was a compromise, but a good one, and I could always continue working on my original coaster idea on the side.
I shifted my focus to designing coasters with teeth that could still fit together into a trivet. This proved to be a better way to learn Illustrator than I realized. To create the teeth on the edges of the coasters I needed to redo my Illustrator file. I started a new file and used the pen tool and grid lines to draw four identical squares with teeth on each side. I used the “snap to grid” feature heavily for this. I then colored in the corners of the squares where I wanted the laser to etch.
With the corners filled, I added a thick, diagonal bar through the center of each coaster, ensuring that the bar and shaded corners were all aligned. I filled these in with solid black for raster etching as well. Once the coaster shapes and patterns were where I wanted them, I removed the coasters on the bottom of the file because the piece of wood I had could only accommodate two.
My file was ready for the laser cutter! Or so I thought. Luckily, I knew I needed to test my work first to make sure nothing was amiss. I used cardboard I found laying around the shop for couple test runs.
The etching worked great, but the cutting didn’t go quite as expected. Only two cuts were made, as you can see below.
Turns out I had missed some wayward objects and had set the stroke value way too low. I went back to my Illustrator file, deleted the extra objects, changed the stroke weight to .1 pt, and saved the file under a new name.
I tried again the following day, starting with another round of test runs. I couldn’t quite get the settings right for cardboard during the first couple of passes. For the first pass, I set the power too high and the speed too low, resulting in ragged burns in the cardboard.
The second time around I corrected my speed and power settings, but still go inconsistent results for the etching. Still, it was good enough for me to try cutting. The laser didn’t cut through enough the first time around, so I had it go again. This time something weird happened: the laser barrel pushed the cardboard, moving the beam out of alignment with the coaster shapes. Lesson learned: use tape to secure material.
I found a new piece of cardboard and tried again. Once more, the etching was inconsistent (though the color gradient was pretty cool), but the etching worked much better. That was until I removed the cardboard to inspect it and then accidentally placed it in just slightly off from where it had been, resulting in jagged cuts again.
“Close enough” I thought, but one more test was needed. I found a piece of scrap press board and placed it in the cutter bed. I changed the raster and vector settings to accommodate wood and hit go.
This test worked like a charm with both the etching and the cutting.
Feeling good about this last run, I was ready for the final step. I placed my piece of pine in the cutter bed, double checked my settings (I turned up the power slightly for the etching to make it darker), and hit go.
It worked marvelously! Check out the final product: