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Building a slicer for 3D food printing

Successfull 3D Printing is like a good recipe: you need to select the best products! In our case, we need at least 4 ingredients: a good 3D file, a good 3D printer, a tasty material and a good slicer. Here we’re not talking about a state-of-the-art Japanese knife… But an essential software !

After over 2000 hours of 3D food printing on the counter, a lot of misfires and great successes, we took a step back and came to this conclusion. There is no good slicer for edible 3D printing. Today, we are pleased to announce our new project: providing the best 3D slicer for 3D food printing. We invite you to discover this in a video and through a series of questions.

What is a 3D slicer?

A 3D slicer is a software that translates a 3D file into a set of digital commands. These control lines identify the movements the machine must perform to make each of the printing layers. Often these commands are compiled in Gcode language and many 3D printers use this file format. When the slicer has generated the file, all you have to do is to send or to drop that Gcode into the 3D printer to start printing.

There are different types of slicer depending on 3D printing technology. Often they are included with the sale of the 3D printer itself. It can therefore be proprietary systems or open systems. Open systems are capable of supporting a wide range of 3D printers (all of those which work with files written in Gcode).

The majority of slicing systems for additive manufacturing are dedicated to FDM technology. This makes sense because hundreds of thousands of personal FDM 3D printers have been sold around the world. You will find many rankings and comparisons of these software in the media dedicated to 3D printing.

Finally, there are several open source software that have been developed by communities. Subjectively, we would like to thank all the developers behind Slic3r. Although the project has been completed since 2018, it remains one of the best software for us. That’s said!

Which settings should be set in a slicer?

The good news is that you find a lot of settings to adjust! The bad news is that you will spend a lot of time understanding the influence and relationship between all these parameters.

But you can save time. Developers have designed beginners modes in several software like Cura, so you can manipulate only the essential settings in the first place. For example, these simplified modes give you access to:

  • layer height
  • the thickness of the walls (envelope)
  • the thickness of the bottom of the room and the top
  • the filling density inside these walls
  • print speed
  • print temperature
  • the type of 3D object adhesion for your tray
  • the size of the filament
  • the size of the extrusion nozzle

If these parameters are unknown to you, we explain them in detail in our two-part glossary. You can also easily find and load 3D printer profiles that will apply manufacturer-tested values across all settings into the slicer.

Unfortunately, these profiles were created to print thermoplastics such as PLA or ABS. When you want to print plastic it’s fine, for food it’s a different story…

Are free 3D slicers suitable for 3D food printing?

Recently, Lynette Kucsma, the founder of Natural Machines, explained in an interview with 3Dprint.com:

“We don’t use standard slicing software or one print speed. Typically with 3D printers that use plastic or metal, you are working with one ingredient and one print speed, but we don’t do that. Instead, we are optimizing for the ingredients you are printing, and customizing it thanks to the different nozzle sizes available. ” 

Lynette Kucsma, Natural Machines

In the book Fundamentals of 3D Food Printing and Applications, authors Antonio Derossi, Rossella Caporizzi, Ilde Ricci and Carla Severini of Foggia University are more specific about the problems associated with the use of these slicers:

“Not less important are the softwares and the codes generated by the slicing software. They definitely control the movements of the printer in all four axes, X, Y, Z and E, but they always consider the properties of thermoplastic materials, such as common PLA and BSA. Of course, when printing food, several unexpected issues may be observed. To name only one, the property of retraction, which allows reducing the pressure at the nozzle during non-printing movements, is estimated considering specific properties of plastic filaments, but for cereal dough or fruit and vegetable pastes, it is usually not sufficient in producing oozing”

Fundamentals of 3D Food Printing and Applications, Chapter 3

To put it another way: it is difficult to transpose the calculation methods developed for a plastic filament to the extrusion of an edible paste. Indeed, there are some mathematics behind the calculation of the path made by the 3D printing head. There are also relatively complex formulas that calculate the relationship between the amount of material extruded according to the speed and distance to be covered. These different equations are applied to calculate the command lines that the machine will need to perform one after the other.

When you use the basic settings of slicers to print food, you get 3D prints with many structural flaws. One way to get around the problem is to use vase modes, also named spiral modes. In practical terms, the slicing software will only consider the outer walls of the 3D shape. Then, it will generate the instructions to mount the walls following a spiral. If you are attentive, you will see that many 3D printed chocolate pictures, are based on vase shapes.

Is there a specific slicer for 3D food printing?

Yes and No.

Yes, because manufacturers of 3D food printers such as ByFlow, Printotaste or Natural Machines have included slicers in their 3D printer sales. We can’t say anything about it: we haven’t tested them, since we don’t own their machines.

For anyone who turns their FDM 3D printer into a food printer : NO. If you’re willing to build new 3D food printers from open source plans, as you can do with the Queensland University of Technology (QUT) project in Brisbane, the answer is also NO.

Therefore, we thought that there were many of us on the same boat and that there was a real need! We’re not the only ones saying that. In the “Critical variables for 3D food printing” chapter of the excellent book Fundamentals of 3D Food Printing and Applications, the authors conclude on the need to create such a slicer for 3D food printing:

“Overall, we are only in a first step of development of the 3DFP technology, and many advantages will be obtained when we will be able to set and to control all printing variables with a high level of accuracy. We believe that two main branches of research must be encouraged: (1) the improvement of the printing behaviour for nonplastic materials; and (2) the precise understanding of the effect of process variables and their optimisation. The first area involves many aspects redefining how the slicing software and the G-code generation making the printer behaviour more adaptive to the specific properties of food…”

Fundamentals of 3D Food Printing and Applications, Chapter 3

Why set up a research project with UTT?

The University of Technology of Troyes is a major French engineering school, with seven research, innovation and expertise platforms bringing together all research teams.

Within these platforms, one is devoted to 3D scanning and virtual engineering. NUM3D has developed various research projects related to 3D printing. Mr. Pierre-Antoine Adragna is a teacher-researcher at UTT and has built the program to generate a continuous trajectory for a given file. This program is the technological brick inside of our software project.

The program inputs the classic parameters of a slicer (speed, nozzle size, layer height, etc.) as well as the design and outputs a functional Gcode. It produces a continuous path to achieve 3D printing, and avoids non-printing movements as well as retraction pauses.

3D food printing: royal icing rosace on chocolate pie.
Dessert Notre Dame: 3D print of royal icing on chocolate ganache

How to 3D print an edible Notre Dame rosace?

To demonstrate the slicer’s capabilities for 3D food printing, we gave ourselves a challenge:

  • Choose a 3D file that cannot be made by a pastry chef,
  • Select a design that is so complex that it cannot be processed in vase mode,
  • Use a very viscous material,
  • Print the 3D object directly on a dessert,
  • Produce the major piece of the dessert composition (rather than just a decoration in a dessert on plate).

This led us to choose the file of the southern rosace of Notre-Dame de Paris, which you can easily find on platforms to download 3D files.

Honestly, the Gcode file worked the first time. In addition to having a great program, we have been 3D printing royal icing for a long time. Therefore, we had a good set of parameters and a sustainable recipe. The bulk of the work has been to adjust the planearity of the chocolate pie, and it’s no joke!

The demonstration was made on a form with a simple extrusion in height. But we are confident that we can make more complex 3D shapes.

What are the next steps for 3D food printing slicer?

Today, we need your feedback and hear about your interest. We are ready to test other files, other materials for further demonstrations.

Also, we would like to produce more files for other food 3D printers. This way, we can together produce a wider variety of tests. Our interest in this phase is to produce the most accurate specifications before developing the user interface.

Finally, we are looking for partners willing to co-finance this development with us in collaboration with the Technological University of Troyes. This may take the form of a pre-sale of a license for example.

What would you like to print in 3D with food? What do you think of such a 3D slicer? At the Digital Patisserie, we can’t wait to hear from you!

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