Making a full-color inkjet 3D printer

When Aad van der Geest first heard of 3D printers decades ago, owning one of these machines was just a dream. But for Aad dreaming wasn’t enough and with his inventiveness he was already one step ahead. He has now created the ‘Colorpod’ – an add-on for his Ultimaker that allows him to print in full color, using the same powder and binder technology found in expensive binder jetting machines.

The Colorpod is based on the binder jetting 3D printing technique: a liquid binding agent, like water, is deposited onto a layer of powder, for example PVA powder. The water bonds the PVA powder creating a layer of the print. The build plate is lowered and a new layer of powder is applied, and this process is repeated until the object is finished. Color ink from a regular inkjet cartridge is used used in addition to the water to add any color to the print.

Colorpod step 1Apply and level powder
Colorpod step 2Print with water and ink
Colorpod step 3Lower platform
Colorpod step 4Repeated until finished

You can see the Colorpod prototype being installed on an Ultimaker 2 and printing in the following video:

This Colorpod is the culmination of decades of work. Aad’s journey started as a maker studying electronics at a technical college. Since 1992 he has been an independent product designer with various experiments and projects to his name. From very big projects in the agricultural sector to the very small, like special calculators, were tackled by Aad.

Colorpod powder print examplesColorpod printhead and prints

In the early ’90s Aad heard about rapid prototyping and 3D printing for the very first time. He found it really fascinating but just couldn’t get involved because of the price tag. Being an inventor, Aad knew what he had to do: he had to invent his own. He proceeded to spend a lot of time experimenting and trying out various approaches. Aad’s first idea was a sand and plaster machine. It took him over a year to realize this idea, but he successfully did it. This was Aad’s first introduction to building a CNC machine and controlling stepper motors:

Sand and plaster 3D printer prototypeSand and plaster 3D printer prototype from the ’90s

This project was a great process that helped him get more familiar with the mechanics, but the outcome still wasn’t great due to difficulties with reliability and not getting strong, functional models. But invention isn’t about getting it right first time and the entire experience led to a color 3D printer which was the true predecessor of the Colorpod. Ingeniously, to create this color 3D printer he used the mechanics of a regular 2D printer, so he could fully focus on the materials and print results.

This Frankenstein-style color printer evolved into what we know today as the Colorpod. When Ultimaker got word of his research an Ultimaker printer was made available for Aad to include in his process. Ultimaker’s open source nature gave Aad all the technological freedom he needed to further his work without having to create an entirely new motion system from scratch.

After thousands of no’s, he finally arrived at his yes moment – the Colorpod was born! Well, it’s not completely finished yet, but it’s well on the way. The Colorpod add-on prints in a resolution of 300dpi and usually creates layers of approximately 0.25mm. The layer height depends on the size of the powder particles, which are usually 0.15mm in diameter. At the moment the prints are rather brittle and require a bit of post-processing with sprays or glues before they become functional. But still, it’s great to see the progress he’s making.

Close-up of the installed ColorpodClose-up of the installed Colorpod

A more direct combination of the Colorpod binder jetting principle with the FFF nature of the Ultimaker printer is also on the horizon. In fact, Aad thinks that in the near future the PVA powder could be used as support material for FFF prints and that the inkjet color system could be used to create fullcolor FFF prints.

Using powder as support for FFFUsing powder as FFF support
Using inkjet to color FFFUsing inkjets to color FFF

So for now Aad is continuing development and hosting workshops where he shares his Colorpod with the attendees. Looking to the future, Aad is currently considering moving into production as he envisions more inkjet solutions coming to market in the near future. He’s looking for beta-testers, so if you’re interested now is the time to sign-up!

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