3. Computer-controlled cutting¶
This week I defined laser cutter settings with my fab academy classmates, created a sticker through our lab’s vinyl cutter, and created and cut out a laser cut file through parametric design.
Vinyl Cutter¶
A vinyl cutter is a machine that creates stickers from sheets of vinyl. It works by controlling a small blade to follow a path that will eventually cut out a sticker. Our lab has 4 Sillhoete cameo 2 vinyl cutters. Our lab uses the Silhouette studio software to design and cut the stickers.
Our vinyl sticker assignment was to “cut something on the vinyl cutter”. I decided to make the fab academy logo. To do this, I cut four different stickers- a white background and each third of the logo- in each color. I aligned them by adding a square outside of the sticker, and by lining the squares up, the sticker itself would be aligned. The sticker turned out fairly well - the individual stickers aligned very well- but I did not apply the assembled sticker perfectly, so there were a few bubbles in the final product. Overall, I am pleased with how the sticker turned out.
To create the sticker, I first imported the fab academy logo into Sillhouete Studio:
I then used the “trace” tool to create the cutout from the image, and added a small square in the corner that would allow me to line up the assembled pieces:
I then copied and pasted the previous design into four different files, and cut away everything but the piece I would cut:
I then used our vinyl cutter to cut out each part of the sticker in four different colors- red, green, blue for the arms, and white for the background. My sticker was fairly simple, so it was not extremely difficult to assemble. I started by weeding away the excess material from the four different parts:
I then attached transfer tape to each part except for the white background:
Then, I attached the four parts together by lining up the square in the corner, and applied it to the window where we put our stickers:
The final sticker came out pretty well. Each part assembled nicely, and there are no major air bubbles on the sticker. However, when I applied the sticker to the glass, there were a few air bubbles.
Laser Cutter¶
A laser cutter uses a powerful laser to blast through different materials. Similar to a vinyl cutter, it follows a path, but laser cutters can cut through much stronger materials than vinyl cutters and cut over a larger area more precisely. Our lab has four laser cutters- three that are about 20x30 inches and one larger one that is about 30x40 inches. Currently, we are only using two of the cutters - the larger one and one of the smaller ones - because we ran into some software problems with the other two.
Group Assignments - Settings¶
Our group assignment was to “characterize your laser cutter’s focus, power, speed, rate, kerf, joint clearance, and types”. Our group work can be found on our group site under the first assignment. My main contribution to our group was getting settings for speed, power, frequency, and kerf for each material we used (1/8” cardboard and wood), as well as defining a few of the terms. To characterize the settings for each material, I ran a color mapped file, where I could change settings on 6 different lines to find the most optimal ones. To find kerf, I cut out a 1-inch square and used calipers to find the difference in width.
Personal Assignment - Parametric Design¶
Our personal assignment this week was to “design, lasercut, and document a parametric construction kit”. I already had a good understanding of parametric design from modeling my final project in Fusion 360, so I used fusion again for this assignment. For my kit, I decided to design a few pieces that could be creatively slotted together.
File¶
I created circle, rectangle, and triangle pieces for my first design. I created parameters for piece dimensions and for the joints. The file did not take very long - I finished it in about 30 minutes.
Cut 1¶
After designing the file in Fusion, I uploaded it to our engineering google drive and downloaded it onto one of the computers for the laser cutters. I followed a workflow written by previous and Fab Academy students Kai Vincent and Teddy Warner for using our new laser cutter.
I started by importing the file into Corel draw, used the virtual segment delete command to delete some unnecessary lines (construction lines in Fusion 360 save as normal lines), and sent it to the laser cutter.
The cardboard cutouts turned out well, but I noticed a few problems with the design. First, the joints were not deep enough to grip well. I fixed this by adjusting my “joint depth” parameter. The other problem was the joints on the triangle were too close together. I fixed this by basing the joint on the midpoint of the leg instead of from the center of the triangle.
I also decided to make the pieces a little bit larger. I increased the parameters for piece sizes, and they scaled up with no problems.
Cut 2¶
After the first cut, I decided to design a 90-degree joint. To do this, I designed a wedge joint in Fusion 360. This joint is much stronger than the other joints because it has a pin that holds the two parts together.
I also decided to experiment with kerf bending. I designed a leg piece with many lines running down it that would weaken the piece, allowing it to bend. The piece will then have some weaknesses along the cut where I can bend the piece.
I then cut this out with the laser cutter. The piece cut out with no problems, and I was able to integrate it into the other kits.
I designed the pieces so that they could be integrated into one of my previous cuts, and it was able to assemble well.
My final kit consists of three flat pieces- a triangle, rectangle, and circle, and 2 3d pieces- a kerf bent rectangle and a T joint:
I learned quite a bit from parametric design. I had used it in the past, such as in my final project design in CAD week, but it was especially useful this week. I had some problems with joint sizes, but I was able to adjust some variables in my design and they were easily fixed.
This week’s files can all be found in this zip file.