Week 12. Molding and Casting¶
This week we will work with molds to implement the final project.
Group assignment:¶
- Review the safety data sheets for each of your molding and casting materials
- Make and compare test casts with each of them Compare printing vs milling molds
Individual assignment:¶
- Design a mold around the process you’ll be using, produce it with a smooth surface finish, and use it to cast parts
Learning Outcomes¶
- Design appropriate objects within the limitations of your process
- Demonstrate workflows used in mold design, construction and casting
Group Assignment: Safety and Test Cast¶
MATERIAL SAFETY DATA SHEETS¶¶
The materials to work with are: gloves, wax, scale, lenses, disposable cups, and sorta clear 37 silicone. Safety: Use in an adequately ventilated area (room-sized ventilation. Wear safety glasses, long sleeves, and rubber gloves to minimize risk of contamination. Use only vinyl gloves. Latex gloves will inhibit rubber curing. Store and use the material at room temperature (73°F/23°C). Warmer temperatures will dramatically reduce working and curing time.
The materials we have at the Fab Lab Pasco are Sorta Clear 37 Silicone. We look at the technical sheet of the product.
We begin to make the combinations of each pot, approximately 2,245 grams.
We measure on the scale with the disposable cups once the combinations have been made. Cure Inhibition: Addition-cured silicone rubber can be inhibited by certain contaminants in or on the pattern to be molded, resulting in stickiness at the pattern interface or a complete lack of cure throughout the mold. Latex, tin-cured silicone, sulfur clays, certain wood surfaces, freshly molded polyester, epoxy, or urethane rubber can all cause inhibition. If you are concerned about rubber/surface compatibility, a small-scale test is recommended. Apply a small amount of rubber to a non-critical area of the pattern. Inhibition has occurred if the rubber is gummy or fails to cure after the recommended cure time has elapsed. Because no two applications are alike, a small test application is recommended to determine suitability for your project. Curing: Allow material to fully cure at room temperature (73°F/23°C) before demolding SORTA-Clear™ 37 cures in 4 hours.
In a work meeting with colleagues Ronal Noel Vilca Apolin from the city of Huánuco, Renzo César Samaniego Ricra from the city of Cerro de Pasco, preparing for teamwork from the digital manufacturing laboratory Pasco.
The mixture of material part A and part B is calculated to obtain silicone 2,245 grams. grams of each part
A keychain has been made with the srm 20 which shows the manufacturing process below and here we will fill the silicone.
Sharing information about what we are doing at the Cerro de Pasco fablab and the colleague in the city of Huánuco
Checking the weight of part A of the SORTA-Clear 37
Checking the weight of part B of the SORTA-Clear 37
Once both parts have been mixed for 5 minutes, they are poured onto the keychain design made in wax.
Once the entire interior of the wax has been filled with silicone, we verify that it is flush with the surface of the wax where the design is located.
We begin to remove the silicone from the wax after 4 hours according to the technical sheet.
Once the silicone was removed without any difficulty from the wax mold, it could be taken out as seen.
The excess parts of the silicone were then removed with scissors.
This image shows the wax that made the mold and the silicone.
We beat the prepared chocolate material to see the consistency and pour it onto the silicone material that at this moment serves as a mold and leave it for 2 hours to solidify as seen in the figure.
Mold Design¶
This image shows the beginning of the drawing of a 55 degree straight line.
In this image 25 additional lines are designed to the first line
Here the upper part of the tower is designed with 2.5 teeth as seen in the figure.
Completing half of the tower with the measurements shown
Tracking the designed lines.
Shaping the edges of the tower in an oval shape
Giving an oval shape to the lower part of the tower design.
Processing axes with the rotate tool
Once processed with the 360 degree rotation completed from the axis, the figure of the tower is complete.
Starting the design of the box that will contain the tower
Complete box design for filling the material
After the design, the finished 3D printing of the two boxes with the tower mold is observed.
Here are the materials we will use to evenly mix the material in a glass to fill the 3d printed container.
Emptying the material into the container
Finishing pouring the material into the printed object
Checking that we need to clean by removing excess material
Once it has finished drying for a period of 6 hours in this case, we proceed to carefully lift the material.
Comparing the positive and negative of design and dried material
We can see the two pieces that when joined together we can obtain an edible material mixture in the form of a tower.
By joining both molds we can obtain results with food material according to our needs.
Conclusions:¶
- I have been able to learn that starting from a design made in this case with Onshape, it has been possible to materialize through a 3D print
- Using materials A and B as explained above, combining them appropriately, you can obtain moldable material according to our needs.
- Since the molds we obtained are for food use, we can respond to future needs.
- The collaborative learning of my colleagues helped me to strengthen my knowledge and other cases to learn from the beginning