# 4. Computer controlled cutting¶

This week I used actual machines,laser cutter and vinal cutter, to create 2D products.

## Group assignment¶

For this group assignment, we created two combs to define offset size becuase of kurf of laser cutter.

By fitting these combs each other and comparing printed numbers (sizes of gaps) with actual thickness of cardboards, we could know difference between actual and desired cutting sizes. In our case, thickness of the cardboards was about 2.8mm. And the most appropriate actual size of gap to fit comb rigidly was 2.6 mm.

From the result, we calculated offset that should be considered to use laser cutter we would use.
The offset was (2.8-2.6)/2=0.1(mm)

## Individual assignment¶

### Laser Cutter¶

For the individual assignment, I firstly sketched some images of the assembled product. As following pictute shows my idea was to create rectangles that can be assembled in multiple ways.

Next, I drew 2D CAD data to be assembled into a rectangle. The first drawing and parameters are shown below.

To prepare to cut cardboards, I exported the subject SVG file and edited the file by the laptop in Fablab Kannnai. By using the laptop, I defined variations of cutting for each line. The laser cutting machine has a lot of cutting patterns including cutting out. However, in my case, only “Cutting out” was used. To apply the cutting pattern to lines, I should select “Red” color to the lines. After completing applying cutting patterns to all lines, I chose “Print” to send the cutting data to the application of the laser cutting machine.

Next, I set the laser cutting machine to execute cutting. Basically, I followed this tutorial to prepare the machine.

Afetr cutting cardbpard based on the first design, products were shown in below picture.
It looked like good, but when I tried to fit these comoponents, sizes of convex and concave portions were not appropriate so that components did not fit rigidly.

Then, I measured the sizes of convex and concave portions. The result said that the actual size of convex was 3.57 cm (desired size was 3.85cm) and the one of concave was 4.4cm(desired size was 3.85 cm).
So, I realized I completely misunderstood about “offset”. After realizing it, I set parameters again like below figure.

After the second cutting, I tried to assemble the components again.
Finally, I succeeded in making these components fit rigidly each other.

### Vinyl cutter¶

For the outcome of usign vinyl cutter, I worked Sand Blast to print my 2D design on a glass. For this work, I chose SNOOPY drawn by Inkscape in the last week.

First of all, I installed required software to use vinyl cutter in Fablab Kannai. The name of software was “Silhouette Studio”. After downloading it, I opned my 2D drawing on Silhouette Studio like below figure.

The Vinyl cutter would cut via pink line like below picture. For now, I let the vinyl cutter cut very narrow lines.

Next, I should choose the area to peel off. My instructor adviced me that the area peeled off would be white because of blasted sand. So I peeled off like below picture.

After peeling off extra areas, I attached cutted vinly on the glass. Finally by blasting sand around the glass, I created my original glass.

### Distribution¶

All files created for the assignment can be donwloaded from gelow links.