Presentation

The Royal Wax Printer is an Artistic Research and Development Project at the Royal Institute of Art in Stockholm. The project was presented January 21, 2019. Below follows a summary.

From the presentation at the Royal Institute of Art Research Week. 

The project phases and timeline

The timeline-bar above shows the different major phases for the project mapped up over time. All the way from the first idea for developing a wax printer to the finished machine and what the future implementations of it can be. Below are more in depth explanations of the working process during each phase and some background to the project.

Pre Wax-3D-printer 

Between 2013 and 2016, the 3D-Lab, the Glass & Bronze workshop did a number of variating tests of castable and steamable 3D-prints, aiming to find  the perfect link between the three workshops. We did tests with 3D-printed plaster moulds for glass casting, sla-printed wax and pla prints for bronze casting. The conclusions from these tests were:

The 3D-printed plaster moulds for glass casting worked but the prints were fragile and needed reinforcement for casting which was complex and time consuming. The technique also suffered from artistic/exploration limitations once printed.

The sla wax prints were hard wax and contained a lot of plastic. The prints could be burned out for bronze but not steamed out for glass.
None of the methods worked smoothly for both bronze and glass casting.

Burning out pla prints works well for bronze casting (see image above). However, strong chemicals are needed when perfect smooth surface is required on pla prints. It is also not possible to steam out pla prints, for glass casting.

The only method that worked for both bronze and glass casting, without using chemicals, was making wax copies of the prints (see image below).

The question now was: Could we skip the “wax copy” part and find a 3D-printing technique that worked for both bronze and glass casting?

Castable wax, was what the Glass and Bronze workshops had in common. Therefore, a printer printing in the castable and steamable wax that the bronze and glass workshops were using, was the solution.
Now we had the idea. But was it possible to do?

The research, with plaster-printed-moulds technique, by Matthias Gayle & Jorgensen Tavs (2012) Falmouth University (see image above), led us to try this method during the 3D-Labs KU project "Print-Up" during 2012-2013.

Idea, Plan and Artistic possibilities

We took the idea; building a wax printer that could print in sculpture waxes, to Stockholm Makerspace in 2014. Esther Ericsson pitched the project concept to some Makerspace members, among them Erik Cederberg. He looked at her drawing and came up with a solution after about five minutes. Two years later, they became project partners, together with Ulrika Rosengren Gustafsson and Anneli Scheutz, in a research funding application called Digital Wax.

The research we did on existing wax printers, showed that The Royal Wax Printer would be the first of it’s kind. Not only would it be more low-cost and environmental friendly, than existing wax printers, since it would print in pure sculpture waxes. But The Royal wax Printer would also mean new possibilities for artists bringing digital tools like 3D-scanning and modelling closer to bronze and Glass workflows. Some key features are:

• Unique 3D-printer 
• Printing in sculpture waxes which can be steamed and burned out. 
• Big print volume: 750x750x750mm 
• Low cost and environmental friendly
• Printing in pure sculpture waxes. Recyclable material. No chemicals involved
• Improve working methods
• Combining 3D-modeling, 3D-scanning and 3D-printing  technologies 
• Skip mould making for wax copies
• Securing original and enables artistic expressions
• Complex geometry and scale changing freedom
• ontinue working on the object as from a basic form

Artistic possibilities with the printer

The Royal Wax Printer in combination with digital tools will lead to new artistic possibilities. The RWP will contribute with it’s own patterns, possibilities and limitations for artists to work with and explore.

Design & concept

The technical solutions and design for the printer was done by Erik Cederberg (Cederb AB), Founder of Stockholm Makerspace.

The concept is based around feeding molten wax through a nozzle and extruding it layer by layer, in the same fashion as FDM printers that work with plastic.

To reduce the moving weight of the 3D printer and make refilling easier, most of the wax is contained in a larger vessel and then fed to the print head in a molten state.

This system is constituted of three separate sub-systems:

1. The Print Head
2. The Wax Delivery System
3. The Melt Chamber

The Print Head

This part has to be able to feed a easily controllable and very repeatable amount of a molten wax and deposit in on the build plate.

We did put down quite a lot of research into different types of ways to control the wax feed.

The main requirements were:

- Able to work heated to temperatures of up to 100C+

- Move a constant volume of material for a known input value, even with varying back pressure, in volumetric flow rates between 1ml and 50ml per minute.

- Able to keep a constant flow to the nozzle, not having to pause to do a fill stroke or change direction.

During our research phase, we looked at pressure fed screw dispensers & needle valve dispenser heads, but the screw dispensers did not work well with low viscosity mediums, and both the screw and the needle valve was sensitive to input pressure and back pressure at the output.

 

We then progressed towards different type of pumps, including external gear pumps, rotary gear pumps, rotary vane pumps, lobe rotor pumps & progressing.

Out of all these, the most promising were these two types:

• External Gear pump
• Progressive cavity pump

So which pump did we choose? Read more of the story here.

 

To interface the pump we did choose in a reasonable easy way with common 3D Printer Electronics (Step/Dir interface) and still be able to implement functions like a max torque limit to protect the pump if for some reason someone tried to extrude wax without waiting for the wax to properly melt, locking the rotor, we drive the pump with a Clearpath servo motor from Teknic, Inc.

The final design before ordering components

The printer is designed to print wax models with FDM technology to be used in lost-wax technology for glass and bronze casting.
The print head is specially built for us by ViscoTec Pumpen-Dosiertechnik GmbH and fed with molten wax through a heated hose from a pressurized vessel with riser pipe.
The printer's mechanics are based on the C-Beam system from Ooznest, the control card comes from Cohesion3D, and the print head is powered by a Clearpath servo.

Dialogue & Development

When the design was finalized and the funding was in place we could start ordering the components.

Ulrika Rosengren Gustafsson  Head of Glass workshop KKH

Anneli Scheutz Head of Bronze Workshop KKH

Erik Cederberg Cederb AB Founder of Sthlm Makerspace

Esther Ericsson  Head of 3D-Lab KKH

Martin Christensen  Teacher 3D-lab KKH

Dennis Härmä  Teacher 3D-lab KKH
Jonas Mickelsson   Intern 3D-lab. 3D-print operator Nackademin

ViscoTec in Germany required tests of wax melting point

Ulrika and Anneli made some tests of melting behaviour for the waxes that will be used in the printer. The test results were then sent to ViscoTec in Germany together with wax samples.

Conclusions from melting tests

New customized eccentric screw pump from ViscoTec

ViscoTec in Germany customized an eccentric screw pump to meet the needs for molten wax extrusion. As a mechanical base for the printer the WorkBee CNC router kit was a good solution.

The eccentric screw pump has arrived. A happy day for everybody involved in the RWP project!

Jonas Mickelsson, intern from“3D print operator” at Nackademin, did a great job putting together the CNC/printer base parts from Ooznest.

Once the C-Beam system was assembled it was time to work on the cables and electronics.

Designing, 3D-modeling and 3D-printing customized parts was done by Dennis Härmä and Erik Cederberg.

We have 3D-printed approximately 70-80 customized parts for The Royal wax Printer.

Testing the machine

Future

Now the interesting part starts with artistic exploration of the new possibilities the printer offers. Art students at the Royal Institute of Art and artists will be able to work with the printer to find different ways of working with it. 

The printed wax objects can be used as they are or be processed in a variety of ways; such as removing or enhancing the machine’s own created patterns, continue working on the object as from a basic form, or print out digital variants. The wax-3D-printer will entail a whole new way of working and opens for experiments.