Wildcard Week: vaccum forming

vaccum machine maykuformbox

This week, we are getting so close to the end of FabAcademy, and I’m feeling both excited and nervous. During Wildcard Week, I explored an exciting fabrication method: vacuum forming using the Mayku FormBox. In this process, a thermoplastic sheet is heated and then pulled over a 3D model using vacuum pressure to create a precise negative mold.

I designed a small object in Fusion 360, originally intended to be used as a mold for soap or chocolate. In the end, I decided to use the vacuum-formed mold for wax casting and created a candle.

Design Preparation

I began by creating a simple sketch in Fusion 360 to design a rectangular object.

The design is compact and features sharp edges—no rounded corners—but still worked flawlessly for vacuum forming. I made sure to avoid any undercuts to ensure the object could be easily removed from the mold.

For the design, I chose our FabLab logo. I modeled the lines of the logo as raised (embossed) features to create nice, visible details in the final vacuum-formed mold.

I also made sure that the object was slightly taller than the final wax cast, since a bit of height is typically lost during the vacuum forming process due to the stretching of the plastic.

Since my object had a relatively flat surface, I drilled small holes into the model to avoid trapped air and ensure a clean form. These air channels help the plastic conform more tightly to the details of the model.

After modeling, I exported the design as an .STL file and printed it in PLA using a BambuLab A1 mini printer. How to work with the BambuLab slicer i showed it in Week5

During the setup, it was important for me to use a low infill percentage. Therefore, I adjusted the settings to 5% infill.

Mold Setup

After the print was finished and cooled down, I placed the object centered on the perforated surface of the FormBox. It is important that the object stands firmly and adheres well to the baseplate – double-sided tape works well for this.

Next, the frame with the vacuum forming material is moved into the upper position and the heating elements are activated. After about 30 seconds, the plastic softens and starts to sag slightly – this is the moment when the frame is quickly pulled down and the vacuum starts.

Here you can see the important buttons. On the right is the power on/off button. On the left, there are the heating dial and the timer dial. I set the heating dial to the maximum temperature. The Mayku FormBox offers only basic controls.

My setup for Mayku Form Sheets material:

The heat could be set to four levels, and I connected an industrial vacuum cleaner for suction, which operated at a fixed strength—approximately 4 bars, displayed on the vacuum’s control panel.

For the forming process, I used a standard thermoplastic sheet that was compatible with the FormBox, but unfortunately, the exact material type was not specified.

Additionally, I connected the dust extractor and set it to medium power. The ideal setting varies depending on the dust extractor used; since we have an industrial vacuum, the medium setting worked better than a stronger one.

Within seconds, the material tightly conforms to the model. Once cooled, the formed shell can be removed.

Material:

The Mayku Form Sheets are 0.5 mm thick white plastic sheets designed for use with the Mayku FormBox. The Cast Sheets are suitable for creating decorative objects, prototypes, and packaging. Here you can find the sheets

Result and Finishing

The resulting mold was clean and detailed. Small unevenness on the sides were caused by print lines in the PLA object – these could be improved by sanding before vacuum forming.

Afterwards, I used the mold as a casting form. For my test, I heated candle wax in a water bath – using a tealight candle – and carefully poured the liquid wax into the mold.

The result was surprisingly stable and detailed.

files Fusion file stl file gcode file