4.140/MAS.863

Where Emilee Johnson Tries to Make Almost Anything

Molding and Casting

So this week we had the opportunity to try out some molding and casting. I've been a bit interested in this for awhile because work on a previous project had me strongly consider it as a way to cast a sleeve into a shell I was working with. Ultimately that's not what I ended up doing for several reasons, but I watched many very cool demonstrations on YouTube that made me want to try it out in some other context. This week was a bit difficult in terms of time because there were a lot of issues with the west section modela, and scheduling time to get on the machines due to how long the projects take also was tedious. Ultimately though I came out with a finished product that I'm relatively pleased with given that this is my first attempt. I am also going to add in a note that I forgot to take into account this week: It's to my benefit to pull often even if I'm not updating. Otherwise it takes forever and a second to get an updated version on my computer so I can merge/add/push whatever I'm doing with my information.

Project 03a
Here's my model for the week. Yes, I decided to be a nerd about it and it is Star Wars. I wanted something with symmetry and I was watching The Empire Strikes Back when I was designing so I figured why not. I also made a quick one of Texas because I was thinking of some friends who just moved there, but due to time constraints decided to only make one this week. I will likely do the other by the end of term though just for fun. I intended to mold chocolate as my final product.
Project 03b
Here's the modela....hard at work....finally. I used the fab module for it of course. The bit size of the endmill is 1/8. Given the nature (simplicity) of my design, I only did a rough cut because everything is square level changes. It was about a 20 minute job. I used the double backed tape to secure it because I had a really poor experience getting hot glue up on the shopbot when I first thought I was going to use that machine instead.
Project 03c
Finished the first mold. This one is the positive, given that we're casting a mold into it to cast the final product. It turned out about how I expected it to look. The modela missed a couple of really small regions that are probably the result of a low resolution image when I moved it over to the desktop computer from my laptop. They were pretty easy to knock out. That being said, so were the outside walls of my part. I busted a couple of small pieces of it. Going back I would definitely redesign it to have a thicker outer ring and possibly use the 1/16 end mill as well just for precision's sake.
Project 03d
Making the negative mold. I used the OOMOO 25 because it had a quick set time and I was finishing it a bit late.
Project 03d
Final product. I chose the smoothcast plastic material, which set relatively quickly. It was also nice because it came out of the mold pretty well...firm enough to hold it's shame but flexible enough that it didn't break when I took it out. I'd like to make the food safe mold next go at it so my final product can be chocolate, just because I think it would fun to have a consumable product. I think that I could have designed the original image to be a bit more friendly for the methods I used to produce it, but I didn't really have a sense for that before starting. The resolution of the image did impact what the modela milled and that reflects in my final product. That being said, it was a very valuable lesson for the next iteration, and for a first time shot at it I'm pleased that things at least came out in a predictable way with small explainable faults.