Molding and Casting

For this week I explored the molding and casting workflow by designing and fabricating a custom mold in the shape of an animated crochet-style gecko. After creating the mold, I used it to cast a candle using melted wax.

The objective of this assignment was to understand the complete process of transforming a digital or physical design into a reusable mold capable of reproducing multiple copies of the same object.

This workflow involved:

• Designing a mold-friendly geometry
• Preparing the positive model
• Creating the mold cavity
• Casting material into the mold
• Demolding and evaluating the final result

I decided to create a crochet-inspired animated gecko because its organic shape, rounded surfaces, and stylized appearance made it visually interesting while also presenting unique challenges for mold fabrication.

The model was inspired by handmade crochet-style geckos commonly seen in plush or knitted art. Instead of designing a realistic reptile, I focused on creating a more stylized and animated appearance with soft curves and rounded proportions.

One of the reasons I selected this type of design was because organic geometry behaves differently compared to rigid mechanical parts. In molding and casting, smooth surfaces and rounded transitions are often easier to demold and produce more aesthetically pleasing results.

The crochet-inspired style also created a softer visual appearance, making the final candle look decorative rather than industrial.

Before fabricating the mold, it was necessary to think about how the object would separate from the mold after casting. This is one of the most important aspects of molding design because some geometries can trap the part or create undercuts that make demolding difficult.

The gecko geometry was designed with:

• Rounded transitions
• Smooth surfaces
• Minimal sharp internal corners
• Controlled depth differences

These considerations helped reduce stress during demolding and improved the quality of the final cast.

The mold itself works as a negative geometry: the empty cavity inside the mold corresponds to the final shape of the candle.

After preparing the design, the mold fabrication process began. The goal was to create a reusable cavity capable of reproducing the gecko shape consistently.

During fabrication, it was important to ensure:

• Correct cavity depth
• Clean internal surfaces
• Proper alignment
• Enough wall thickness around the mold

These factors influence both the durability of the mold and the quality of the casted object.

Since the final object would be a candle, the mold also needed to resist moderate heat from the melted wax without deforming.

Once the mold was completed, I used it to create a candle by pouring melted wax into the cavity.

The casting process involved:

1. Heating the wax until fully melted
2. Preparing the mold on a stable surface
3. Carefully pouring the wax into the cavity
4. Allowing the material to cool and solidify
5. Removing the final candle from the mold

One important aspect during casting was avoiding air bubbles while pouring the wax. Pouring too quickly can trap air inside the mold and affect the surface quality of the final piece.

Cooling time was also important because removing the candle too early could deform the geometry.

The final result was a decorative candle shaped like a crochet-style animated gecko. The mold successfully captured the main geometry and preserved the rounded aesthetic of the original design.

The project demonstrated how molding and casting can be used not only for industrial manufacturing, but also for artistic and decorative objects.

Some of the most important observations from the final result were:

• The mold geometry transferred correctly to the wax
• The rounded surfaces demolded successfully
• The candle maintained the original character style
• The mold could potentially be reused multiple times

Although this project had an artistic appearance, the molding and casting workflow still required several engineering considerations.

During the design process, it was important to think about:

• Draft angles: to help release the casted part
• Undercuts: to prevent trapped geometry
• Wall thickness: to maintain mold rigidity
• Thermal behavior: because wax is poured in liquid form
• Surface finish: because every imperfection transfers into the final cast

One of the most interesting aspects of this week was understanding how every detail in the mold directly affects the final object. Unlike subtractive manufacturing, casting reproduces almost every surface characteristic present in the mold cavity.