[proj2] casting + molding: wall tile

0. Part Design

A modular wall tile pice with a pocket. The pocket became a problem when creating a CNC cut file – undercuts! In order to acheive the pocket option, I had to either create sectioned cut parts, or mill the same piece twice (front and back), or create a 4-step mold ( instead of 3-step mold as shown below). For the purpose of quick testing, I deleted the pocket.

1. Foam mold milling
Shotbot
1/2″ dia drill bit for roughing
1/4″ dia drill bit for finishing

Carefully sanded all surfaces, and applied gesso to seal porous foam surface. Lastly, I applied diluted soap solution as release agent.

 

2. Oomoo Pour
1:1 ratio between part a, part b
cures in 10 minutes

3. White plastic 305 Pour

1:1 ratio between part a, part b
cures in 10 minutes

next time: need to clamp the two molds together – the liquid solution kept seeping through. What I did on the second pour was that I waited couple minutes after the initial pour (to the seam line), and then poured the rest, and it worked out better.

What happened after I took out the casted part was that the oomoo mold at pour hole was too thin, and it  tore as I peeled the positive part away from the mold. Next time, the mold will need to be at least 3 mm thick to ensure flatness and firmness after the pour.

 

4. Expandable Flexible Foam

expands 15 times volume

Definitely need to clamp down the mold. I pressed down with  my hands but the pressure wasn’t enough (and uneven) to keep the foam from pushing away the two mold parts. I also took out the piece too fast and left a finger mark. But other surface area was smooth.