<. <br>
[Joint experiment](https://fab.cba.mit.edu/classes/863.21/Harvard/people/GabbyPerry/joints.html "Joint experiment"). <br>
####Objective <br>
To fabricate a construction kit using laser cutter.
####Approach <br>
As it was my very first time to fabricate something by myself, I decided not to overcomplicate this task while aiming to create something interesting.
I ended up with three types of basic geometry pieces (square, triangle and circle) to form a cuboctahedron.
<br><img src="./cuboctahedron_sketch.jpg" alt="cuboctahedron_sketch" width="300"/>
<img src="./cuboctahedron.gif" alt="cuboctahedron_gif" width="300"/>
####Metrics <br>
* Laser cutter: Thunder Laser Nova 24 (60W). *based on my web research. The name and watt might be incorrect.
* Laser cutter setting: laser-head speed = 40 mm/s, power = 50%, focus = 6mm
* Material: cardboard, with the thickness of 4mm (approx.)
* Software: Fusion 360 (2D sketch only)
* Protocol: below was my approach.
1. Sketch the concept on the notebook. Calculate by hand the angle and lengths, and number of each pieces required.
2. Draw the construction base kit (6 squares, 8 triangles and 24 circle joints) in Fusion 360.
3. Render a dxf file of each and feed them to the software for laser cutting (lightburn).
4. Confirm that minimum set of basic materials works as planned.
5. Replicate the parts fabrication.
6. Assemble.
7. Examine.
<br><img src="./laser_module.JPG" alt="laser_module" width="300"/>
<br><img src="./laser_parts.JPG" alt="laser_parts" width="300"/>
####Results <br>
* It went well, and I was able to make the final outcome as I wanted in one sequence of protocol (which surprised me as I was expecting a lot more failure).
* From the group experiment, I knew that kerf will be more or less 0.5mm. I thought designing a ditch width of 4mm to accommodate the 4-mm joint parts might just work. My hypothesis was true and each joint fitted perfectly; however, it was so perfect that I had a hard time to fit the last few pieces on while not putting any other pieces off the joint. Probably it would have been better if I cut the corner of the joint, despite a potential tradeoff of losing friction of the joint to retain the parts together.
* I did not anticipate, but because of my circle joint shape, my cuboctahedron became exactly like a coronavirus!
<br><img src="./corona.JPG" alt="laser_parts" width="300"/>
###Vinyl cutting of an MDE sticker<br>
<br>
####Objective <br>
To cut something with a vinyl cutter
####Approach <br>
Cut a same shape with different scales.
<br><img src="./vinyl_des.JPG" alt="vinyl_des" width="300"/>
####Metrics <br>
* Vinyl cutter used: Roland CAMM-1 GS-24
* Pen force: +1.5 (as the vinyl was not cut through with smaller pen forces)
####Result <br>
* The designs on both edge did not cut well. Possibly, it reached the limit of the digital canvas.
* The smallest one looked a little bit rough in shape. I did not check the blade speed parameter, but could have adjusted to see whether it improves the outcome quality.
<br><img src="./vinyl_fail.JPG" alt="fail" width="300"/>
<br><img src="./vinyl_success.JPG" alt="fail" width="300"/>
<br><img src="./vinyl_complete.JPG" alt="fail" width="300"/>
[original files](https://hu-my.sharepoint.com/:f:/g/personal/ttokunari_mde_harvard_edu/Eo_MW5iJhp1GvL7Oqn-jOrYB6G4nvFlrPQ0QWN5hT0okVg?e=J0TZIo "original files") <br>
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