02/25/2024
When we casted the 150th Belt last year, we ran into a huge issue in which chunks of the belt were missing or "Zombified" as we nicknamed it after doing a lost PLA casting. The molds weren't caked in paste wax before being dipped into the slurry, and we thought that was the issue as we could see chunks of the PLA stuck in the mold itself. After a few other classmates had similar results, and they utilized paste wax, we could not figure out why the process kept failing except for a select few.
The running theory was that the white PLA had something to do with it due to the metals present that give its stark white color. So we printed a few in black and white, and The Foundry did some tests to see what would happen. The following are some of the highlights of the results - showcasing some similar issues the black and white PLA both had, as well as some differences.
One interesting response is all four of the plates have a chunk missing out of the 2D figure's chest, of which is not missing on the original belt. The biggest issues seem to be on the top of the plates, which was the bottom when they were fired to get all the wax, PLA, and paper out of it (on both the tree and plates). This could signify that its getting stuck on its way out of the mold, ontop of other issues it may have.
Out of all the most recent PLA castings The Foundry has done, the only one to come out clean was in green - so that will be the next color we test out (cause why not).
Shoutout to the and Marjee for helping conduct this experiment so we can mitigate issues on future belts!