Assignments
Group Assignment
- Review the safety data sheets for each of your molding and casting materials, then make and compare test casts with each of them.
- Compare mold making processes.
Individual Assignment
- Design a mold around the process you'll be using.
- Produce it with a smooth surface finish that does not show the production process toolpath, and use it to cast parts.
- extra credit: use more then two mold parts.
GROUP ASSIGNMENT
More specific detailed from the worked done with Ernesto Castro in Fab Lab Universidad de Lima here
Z A M A K M o l d i n g a n d c a s t i n g
For the group assignment appart from comparing both of our molding and casting with silicone and resin, we decide to try ZAMAK metal process.
Metal casting process
- Design and fabrication of model
- Sand preparation for the mold
- Molding in sand
- Heat the metal
- Metal casting
1. Design and fabrication models
I design a kind of medal with the logo of the Universidad de Lima and the fab academy logo from the front and for the back some drawings of petals and flowers that I wanted to try since I have been using all my drawings in differents assignments. I divided it in two parts since for the silicone casting you need a flat part for casting. However for metal casting the 3d object does not need to be divided. That is why at the end we did each part separated and started with de ulima logo.
2. Sand preparation for the mold
Molding sand is composed of silica sand with water and clay. This makes it malleable and adhesive, so the piece leaves a sufficiently compact imprint as a mold.
The sand must be compacted in the metal box they have in the laboratory, which is divided into two parts: the body and the lid. However, since I had already divided the object into two parts and it had one flat side, we only filled the body and left the lid uncovered to pour the metal into it.
3. Molding in sand
Once the sand is compacted, place the model in the container and compact it. Since it's not a 3D object, we don't need a feeder hole or a vent hole, as one side will be exposed to the air. Carefully remove the model.
4. Heat the metal.
The metal to be worked is ZAMAK. It must be melted above its melting point. It is composed of zinc, aluminum, magnesium, and copper. It is nontoxic and dries quickly, making it a popular teaching material for students in the laboratory. It melts at 430°C.
5. Metal casting
Finally, we poured the zamak into the sand mold and let it cool for approximately 5 minutes until the metal had solidified. We carefully removed it with protective gloves and pliers, then soaked it in water to cool and cure. Finally, we polished it for a better finish.
FINAL GROUP METAL CASTING
other individual assignments in metal
We also tried the metal casting with dome personal objects. Ernesto tried with a topography he made for his individual assignment and as my model of that was sticked to the silicone mold I made I still wanted to try with my rawings so I did the other side of the medal I design but I just cast the flower in center . They ended looking fine and we polish them too at the end.
INDIVIDUAL ASSIGNMENT
For this assignment I decided to still making my drawings in 3 dimensions. This time I tried with a kind of tree and make it like a balloon texture with holes to make it look like a pencil holder.
molding in silicone
1. design and fabricate the mold.
pencil holder design. Resin and PLA 3d printing.
ERROR in height of the mold. I printed 5mm extra and stick it.
2. Test 1 with silicone
Materials.
First I calculated the volume of the mold with water.
Silicone measure till the density I calculated + 4% extra in case of error.
Silicone step 2 in 4%.
Dont forget the release agent in the mold so the silicone doesn't stick in it.
The silicone is poured into the mold.
Silicone molding done.
3. Crystal resin casting
Preparated the mix with resin part A and B.
Casting still drying.
F I L E S
other individual assignments in metal
We also tried the metal casting with dome personal objects. Ernesto tried with a topography he made for his individual assignment and as my model of that was sticked to the silicone mold I made I still wanted to try with my rawings so I did the other side of the medal I design but I just cast the flower in center . They ended looking fine and we polish them too at the end.
INDIVIDUAL ASSIGNMENT
For this assignment I decided to still making my drawings in 3 dimensions. This time I tried with a kind of tree and make it like a balloon texture with holes to make it look like a pencil holder.
molding in silicone
1. design and fabricate the mold.
pencil holder design. Resin and PLA 3d printing.
ERROR in height of the mold. I printed 5mm extra and stick it.
2. Test 1 with silicone
Materials.
First I calculated the volume of the mold with water.
Silicone measure till the density I calculated + 4% extra in case of error.
Silicone step 2 in 4%.
Dont forget the release agent in the mold so the silicone doesn't stick in it.
The silicone is poured into the mold.
Silicone molding done.
3. Crystal resin casting
Preparated the mix with resin part A and B.