Week 14

This is my 14th week at Fabacademy, this week I learnt a lot about molding and casting. This is the summary of the week assignment:

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

Regarding the group assignment, we reviewed in detail the characteristics of the materials we used this week for our molding and casting work: Ferris Wax, Silicone RPRO and GEDEO Epoxy resin. Also we conducted, along with our instructor Luis and in depth safety training of the materials we used, with special care of eyes, breath and hands protection. Check out all the details of our group work here: https://fabacademy.org/2025/labs/aindustriosa/week14.html

Individual assignment

This week we were asked to design, fabricate, and test a mold. In my case I started the process inspired in the free-shared design of a Fender Stratocaster, one of my favourite guitars, created by Ryan Nein and available at sketchfab: https://sketchfab.com/3d-models/fender-stratocaster-guitar-15a37147641b4c1b963bb494b234593f

Once downloaded, I needed to work quite a lot on the design because it was an extremely detailed design which is impossible to cast by molding at a small scale, so actually I needed to simplify it a lot and switching the mesh to nurbs into Grasshopper in order to merge several parts of the guitar until I had a sufficiently simplified design. Also I decided to modify the scaling of the X, Y and Z dimensions. Epecially the latter one was quite upscaled in order to have a larger neck in the guitar to make my first molding feasible. Here you can see sequentially the process done: simplification of mesh, scaling, mesh to nurbs, merging and spliting the parts of the mold:

Then I added pins and resin chanel plus air chanel:

Next I worked a little bit in refining the chanels for making sure that there is no problems with the flow of the resin. After researching on the internet I found that a good recommendation for ensuring that the epoxy flows well is setting a channel of about 5 mm in diameter:

Finally, after the work in Grasshopper I achieved my mold design, here you can see the final result:

Because my course mates Pepe and Francisco also needed to mill their molds, I decided to try to print my mold in the 3D printer with PLA and quite a high resolution (0.2 mm) in order to achieve a smooth surface. Here you can see the result:

However, I realized that the surface was not that smooth as I wanted. Therefore, I decided to apply acrylic onto it on a try for getting better results:

The layers were still visible so I was not happy with the results. Therfore I decided to create a new printed model, this time I used a better resolution of 0.1 mm. Here you can see the result:

This time the layers were not visible and the mold had the quality necessary for the work, so I started working with the wax (see the details of the product and its manipulation on the group assignment section):

And my first ever mold was ready, I was happy with the results. After molding, I started the casting with the epoxy (see characteristics in group assingment section), this time with special care of breath, eye and hand protection. Here you can see the result of the casting:

So finally I got my first casting. This week was very difficult, I did not know that this task may be so challenging. It is very important to think very carefully about the mold and its characteristics before fabrication because there are many things that can go wrong. Also, the resolution necessary for this works is essential for getting polished surfaces, which is not trivial with the common equipment of a digital lab.

Download section and replication

Here you can get all the files of my desinged and fabricated molding and casting work, including the stl files of the mold and vcarve file in case you want to mill it: molding_and_casting.