Computer Controlled Cutting
Hands-down, my favorite toy of all times is LEGO bricks. My desire to build with them has never wavered and to this day I am still a massive fan. As a child, I dreamed of being an architect, so in addition to building with LEGO, I gravitated towards building with Lincoln Logs. To honor both of these fantastic toys, I set out to design a construction kit that allows people to use a simple laser cut unit to build larger elements that could then be used to build larger models. Essentially, the kit will be comprised of pieces that, when put together, form a LEGO-like brick, or a Lincoln-like Log.
I made a few quick sketches to get the basic shape sorted out. I started thinking about a two piece design that would allow the "studs" to always be on top, but quickly scrapped that idea as it meant the user would have to pay close attention to which piece they grabbed when building each element.
I then considered an alternative shape that had the same positive and negative shape on both the top and the bottom, but this design would cause trouble when the element was placed in various rotated positions.
In the end, I designed this single piece that could be inserted into itself to form a highly versitile element.
I designed the part in SolidWorks and took advantage of its equations and global variables to make changing the design super-simple.
I wanted to give MODS a try, so I saved my design as a PNG and then read it into the Epilog program. It was simple to use and it cut well, but the placement in the workspace seemed rather arbitrary and the scale was off. I tried to tweak things a bit, but after producing two bad samples, I decided to skip the conversion to a PNG and just take advantage of the vectors I could extract from SolidWorks. I saved my drawing as a DXF, and then opened it in Illustrator. After making sure to set the line thickness to 0.07 pt, I sent the job to the laser cutter.
I was rather fortunate to get a great press fit the first time! I measured my carbboard to be 4.25 mm thick, so I started by cutting my slots at 4 mm wide.
To verify this was the best fit, my classmates and I created a simple "Calibration Board". It has varying thickness slots as well as sample swatches that were etched with increasing power intensities.
We used the Trotec laser to etch and cut the cardboard to the various power settings shown on the calibration board. Here's how it came out...
Afterwards, I experimented further with the Trotec laser settings and found that these Power, Speed, and Frequency settings work best:
3mm Plywood
6mm Acrylic
These are the settings I ended up using to cut the parts for my final project.
I went back to SolidWorks to build out the rest of my design. I used Excel to drive my model and produce a number of different lengths.
Then I produced a drawing that had views of varying numbers of each piece on it. As before, I saved a DXF, but this time, I used Rhino to push the job to the laser cutter.
I ran several batches and then took home a box full of parts to share with my family.
It wasn't long before my wife and son were building awesome creations and pushing the design to the limit, exploring various ways that these basic elements could connect togehter!
Download my SolidWorks 2018 file
Vinyl Cutting
Inspired by my childhood video games, I decided to cut a series of Space Invaders to place on my laptop. I found many images online that I could just cut directly, but I thought it would be more fun to first build a "PixelArt" model in SolidWorks that I could repeatedly use to generate any pixelized image.
I extruded a simple cube and then patterned the body (without merging the results), so I ended up with an array of cubes that I could individually color. I created three global variables so I can easily change the size of the base cube as well as the length and width of the pixel array.
I exported a PNG of a drawing I made in SolidWorks and then used Mods to send it to the Roland vinyl cutter.
Then I used the typical process to go from the cut sheet to final placement. First, I "weeded" the vinyl.
Then, I applied the release paper.
And then removed the vinyl backing.
Finally, I applied the sticker to my laptop!
