Nozzle Design

One of the easiest ways to influence concrete flow is to adapt the print nozzle. Here you can find several nozzle designs and follow the design process that led to the design we're now using and testing. These nozzle designs can be printed on a 3D printer in PLA or other plastics.

There are several advantages to using interchangeable nozzles made out of plastic on the print head:

1. If the nozzle gets stuck or clogged, it can easily be removed by breaking the nozzle.
2. By changing the nozzle diameter, the behaviour of the concrete layers can be influenced.

Our nozzles can be screwed directly onto a GEKA coupling. The GEKA coupling is connected to the hose, which is connected to the concrete pump.

The nozzle files presented here are parametric, which means the dimensions (or other properties) of the nozzle can be changed in the file. This way, we only need one file but we can design the nozzle to fit our particular needs.

In designing this nozzle, we looked at a few key components:

1. Screw length
2. Room for a wrench to fasten/loosen the nozzle
3. Size (diameter) clearly visible on the nozzle
4. Rubber seal on screwthread end to prevent leaking

The files were created in an open-source 3D modelling program called OpenSCAD: www.openscad.org. In contrast to other 3D modelling software packages, OpenSCAD is text-based, which lends itself very well to parametric design. To open the files below, you will need to download OpenSCAD from www.openscad.org/downloads.html.

• The latest version of the round nozzle we're currently working with can be found here: nozzle_screw_thread_v5.scad
• Our square nozzle: nozzle_square.scad
• Our square nozzle with wings: nozzle_screw_thread_rectangular_with_lips_v2.scad
• Our angled nozzle: nozzle_angled_v3.scad

When you open the file, you will see the following warning in the console: “DEPRECATED: polyhedron(triangles=[]) will be removed in future releases. Use polyhedron(faces=[]) instead.” In the version of OpenSCAD used to create the nozzle (2015.03) this is not a problem and the nozzle will render just fine.