8. Moulding and casting¶
This week, I undertook the task of designing and creating molds for casting. With a meticulous approach to each step of the process, I was able to achieve excellent results in both the quality and precision of the molds and casts produced.
Group Assignemnt¶
In the group assignment, we were assigned to test and evaluate various materials for their effectiveness in molding and casting. My specific focus was on RTV2 silicone rubber, which I researched and experimented with extensively. While I was engaged in material testing, my colleagues Mohammed and Sayed Ali were responsible for documenting our group’s progress and findings. Please refer to their respective pages for more information on our assignment and the materials we tested.
Individual Assignemnet¶
For my individual assignment, I took on the task of designing, creating, and casting a mold entirely on my own.
Designing¶
I worken on Fusion360 to design a 2.5D cat-shape keychain.
To begin, I created a new sketch and utilized a variety of shapes and lines to draw a cat.
NOTES: - I used the mirror tool to ensure that the shape is symmetric. - I used the trim tool to remove the extra edges.
Then, I extruded the shapes with the desired heights.
Also, I used the fillet tool to round the edges.
Finally, I saved the design as an stl file.
To download the stl file click here
Machine Setting¶
The Software used is SRP Player which is to have a view on what will the end result be.
After uploading the STL file, the software provided a clear preview of the design, with step-by-step instructions on the left-hand side.
The preview provided by SRP Player included dimensions of the design, ensuring that the final product was accurate and met the necessary specifications.
When working with the SRP Player software, I had the option to choose the type of milling needed for the project. I opted for a better surface finish rather than faster cutting time, as there were certain details that I wanted to be visible in the final product.
Additionally, I had to consider whether the design had curved surfaces, which was the case with my design. This required careful attention to the milling process, as curved surfaces can be more challenging to mill accurately.
After selecting the appropriate milling options in SRP Player, the software automatically generates the tool path. This allows for accurate milling of the design and ensures that the final product meets the necessary specifications.
Then, SRP Player provides a preview of the final product and estimates the cutting time required for milling.
I then went back and changed the tool path. I chose a 3/32” Square tool for roughing and a 1/16” Ball tool for finishing to achieve the desired level of accuracy and detail in the final product.
The milling machine used is Roland SR-20.
To establish the origin, the center point of the x-y surface of the wax is measured and marked
The wax was affixed to the machine using double-sided tape.
Once the roughing process is complete, a notification will prompt the user to switch to the finishing drill bit.
The end product was remarkable, with clear details and smooth curves.
Silicone Moulding¶
To create the mold, I utilized silicone, beginning by measuring out equal quantities from each container.
After measuring out the equal amounts of silicone, I mixed them together and poured the mixture carefully into the mold.
After waiting for approximately 24 hours, the final result is revealed, as shown.
Casting with Resin¶
1 For casting I worked with resin.
NOTE:
It takes approximately 40 minutes to work with the resin for casting. The curing time for the resin is approximately 24 hours, while it takes an additional 48 hours for the resin to fully harden.
To begin, measure out a 10A:6B ratio of resin A and hardener B.
Once the resin and hardener have been measured, they are mixed together thoroughly before adding black acrylic color and glitter to the mixture.
After adding the desired color and glitter to the resin mixture, it is poured into the mold for casting.
After allowing for 48 hours of curing time, the final result is revealed, as follows.
