A recipe for a 3D chocolate printer

Aksh Dadwan, Bedir Goybulak, Danial Haji-valizadeh, Sangwon Hwang, Thomas Powley and Zesheng Sun

Degree: Bachelor of Applied Science
Program:
- Mechanical Engineering
Campus: Vancouver

Our design solution and process

Our client was Dr. Ahmad Mohammadpanah, a mechanical engineering professor who proposed the project and set out the initial requirements in terms of print speeds and nozzle diameters. However, this project was always about more than building and testing a chocolate 3D printer.

One of our goals from the outset was to empower non-technical people to build their own printers by providing them with a “recipe” of easily accessible components, instructions on how to assemble the components, and guidance on how to use the printer to produce their own edible creations.

The ChocoLUXE 3D printer consists of a FDM printer, a 3D-printed extruder that can be easily attached to the printer and a secondary reservoir to melt the chocolate as preparation to reload the extruder when it empties.

Throughout the design process, we were careful to choose components that would be readily available and easy to assemble by the end user.

There are 3D chocolate printers available, but they cost around $1500 or more, and they are not open source.

In our solution, about 88% of the components are off the shelf or 3D printed.

Only a few components need modification with a few simple hand tools that most people would likely have. Users can use their existing 3D printer to build the housing into which all the components are fitted. Assuming you already have a 3D printer, our components would cost you around $350-$400.

Dr. Ahmad Mohammadpanah

The challenges we faced

One of the first challenges was coming up for a design for the extruder.

We started off with an Archimedes screw design. However, this approach was not successful due to the low pressure it generated. We would need to pressurize the system, which would drive up cost and go against the theme of accessibility. In the end we pivoted to a more straightforward syringe design controlled by a motor.

Another challenge was the material itself.

As an organic non-Newtonian fluid, chocolate is difficult to work with because its properties are not uniform. Dark chocolate, milk chocolate and white chocolate have different oil and cocoa content and will melt at different temperatures and perform in different ways. At the macro level, we found that although various brands will behave in roughly the same way, there is still considerable unpredictability.

The thickness of the layer lines affects the quality of the prints, which is true for regular PLA printers as well.

A lot of trial and error was therefore needed to optimize the printer settings in terms of temperature and flow rate.

What we’re most proud of

We all really enjoyed working with our client on this project.

His expertise in additive manufacturing meant that he had firsthand understanding of the engineering product design process and how much work and time is required to design, test and build a product like this.

It was very rewarding to work together as a team.

And it was great to be designing and building something tangible, where we could immediately identify the shortcomings of our ideas and see where we were on the right track.

The accessibility component of this project also meant a lot to us. We’ve built a product that we can use to 3D print chocolate creations. But more importantly, we’ve created instructions so that other people can build their own 3D chocolate printer at a reasonable cost and with minimal effort.

Our project’s future

A few of us have already started purchasing the components to make the extruder for own 3D printers.

Beyond our group, we see this printer as a way to get kids excited about STEM.

It’s a pretty low barrier to entry for a teacher or club to purchase the components, build the machine and experiment with additive manufacturing in a fun hands-on way. The food industry might also be interested in this product.

Chocolatiers tend to use moulds when designing chocolate sculptures, but 3D printing allows you to make much more complex geometries that could be of interest.