<. <br>
####Objective <br>
design a mold around the stock and tooling that you'll be using, mill it (rough cut + (at least) three-axis finish cut), and use it to cast parts
...could not achieve. I need to update this page after I finally succeed.
####Metrics <br>
**A. Designing part** <br>
* Base design: Ring. I followed [this](https://www.youtube.com/watch?v=lIf9orw1Lzc "this") tutorial for the basic ring design, but I modified the design to make my own ring.
* Software: Fusion 360 and Aspire (converting .stl to shopbot extention with toolpaths).
**B. Milling part** <br>
* Milling machine: Shopbot
* Endmills: .25 inch endmill (roughing) + .05 inch endmill (surfacing)
* Material to be milled: Wax
* Software: Shoptbot's standard software
**C. Molding and casting part** <br>
* Material for molding: Oomoo 30
* Material for casting: Bismuth tin
####Protocols and results <br>
**A. Design part** <br>
1. Determine a basic design. I decided to make a ring. Reasons:
* I knew I would fail a lot, so wanted to design something small.
* My wedding anniversary (Nov 3) was approaching:)
<br><img src="./ring_before_cut.png" alt="image" width="500"/><br>
2. Draw a 3D ring design on Fusion.
3. Cut the 3D model to make it ready for milling to make a wax mold.
<br><img src="./ring_after_cut_1.png" alt="image" width="500"/><br>
My Fusion went really, really slow. It took 3min for every new addition/modification of design. I suspected the WiFi connection, but after trying
3-4 different wi-fi including the one at home, I concluded it wasn't the primary factor as the problem did not solve.
As the result, I spent (am still spending) too much time on deisng modification and ran out of time for sanity check of the mold design.
<br><img src="./ring_mold_fail.png" alt="image" width="500"/><br>
**B. Milling part** <br>
1. Use the above-mentioned sketches.
2. Set up a block of wax with a hot glue gun. Type the dimension into the shopbot software.
3. Change the endmill to a .25-inch one.
4. After zeroing, hit the start button to mill.
It went off soon after the endmill hit the wax, apparently because the glue was not enough.
<br><img src="./milling_fail.jpeg" alt="image" width="500"/><br>
However, I realized a more fundamental problem (finally, at this point. could have been way earlier); i.e. my mold design would not work to create a complete mold to make the ring as designed. Namely:
* I forgot to add a wall in between the different molds
* There was no male-female pair of pins to put the different molds together.
* I haven't designed the holes to pour mold and ventilate the air to avoid bubbles inside the material.
<br><img src="./screen_fail.jpeg" alt="image" width="500"/><br>
Joon helped me re-organize my brain and strategy. It would require 3 different molds as shown on the top of the black board below.
<br><img src="./post_mortem.jpeg" alt="image" width="500"/><br>
Coupled with the slow operation of Fusion (a problem that I have not managed to overcome to date), I could not try the second run.
Lessons learned:
* Write down the processes and rough sketch on my notebook to avoid obvious mistakes like my deisgn failure on mold. I was writing down these in my first few weeks and things usually went well. Time to go back to that habit.
* Supply side project management is important.
##Trying again in December 2021
As this week was a complete failure and I was not going to use molding and casting for my final project, I decided to redo the assignment in December.
I modified the design: see the new designs above. I designed one of the two mold with big margin that contains the other half of the mold as it is a better way to put two pieces together than male-female pins would do.
<br><img src="./aspire_ready.png" alt="image" width="800"/><br>
I milled the wax accordingly.
<br><img src="./mill0.JPG" alt="image" width="500"/><br>
<br><img src="./mill1.JPG" alt="image" width="500"/><br>
I think I got a wrong ball mill for finishing... as I had to work on my final project, and also it at least seemed to do the job for castings trial, I decided to move on.
<br><img src="./mill2.JPG" alt="image" width="500"/><br>
I used the Ecoflex to create a soft mold. It was cured for two days.
<br><img src="./mold0.JPG" alt="image" width="500"/><br>
<br><img src="./mold1.JPG" alt="image" width="500"/><br>
<br><img src="./mold2.JPG" alt="image" width="500"/><br>
<iframe width="560" height="315" src="https://www.youtube.com/embed/iIO2zsZIe5g" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
Then, instead of bismuth-tin alloy, I decided to use chocolate as a casting material.
<br><img src="./choco.JPG" alt="image" width="500"/><br>
<br><img src="./pouring.JPG" alt="image" width="500"/><br>
<br><img src="./poured.JPG" alt="image" width="500"/><br>
<iframe width="560" height="315" src="https://www.youtube.com/embed/ynd04fprej0" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
The final result was not satisfactory (as expected from the rough finishing of the original wax mold), but at least I managed to get to the end. Spiral growth!
[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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