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JNCTURE is an independent design project created by Matt Callahan Š Matt Callahan 2014

What if desktop 3D printers could rapidly create objects at an architectural scale? While consumer 3D printers are becoming faster, more reliable, and easier to use, the technology has yet to be embraced as a widespread means of production for consumer goods. Objects created with desktop 3D printers are constrained by the limited amount of space available in homes for that technology. Medium to large scale objects sculptures, chairs, lamps, etc. - cannot easily be printed due to these constraints. It is clear that scale is one of the biggest limitations on the functionality of desktop 3D printers. Several attempts have been made to solve this problem, and each approach has costs and benefits. Variations in the capabilities of desktop printers coupled with the potential for software to develop infinitely unique geometry suggests that no single software will be suitable for every scenario. Instead, there will develop an array of tools for designers, each suited to fit particular needs and constraints1.

For other solutions to the problem of scale in 3D printing, see:


juncture: noun a particular point in events or time a place where things join

What is JNCTURE? JNCTURE is a script that allows designers to efficiently print modular parts for architectural scale objects using a desktop 3D printer. The script creates small parts at the vertices of polyhedral shapes that integrate with beams constructed from traditional hardware materials. The junctures function as custom modular framing for organic shapes of any size, giving designers and 3D printing enthusiasts the freedom to think big. The scale of designs made using JNCTURE is limited only by the size and material properties of available hardware materials. It allows for the rapid fabrication of very large, complex geometries using inexpensive materials and technology. In addition, many of the strengths of desktop 3D printing are maximized (easy to create small, complex shapes), while weaknesses are minimized (low print resolution is well suited to creating JNCTURE geometry) because JNCTURE has been built in response to many of the limitations of today’s 3D printing technology.

How does JNCTURE work?


JNCTURE is a grasshopper script that runs inside of Rhino, a 3D modeling environment commonly used by industrial designers and architects. Front: JNCTURE analyzes user generated polyhedron geometry and automatically creates junctures at the corners of the polyhedron.


The script does this by way of three basic steps:

1 Analyze user-generated polyhedron geometries, and create junctures based on a material specified by the designer (dowel, PVC, cardboard, etc.)

2 E 133.1








Create PDF diagrams to guide assembly

















3 Label junctures, export files for 3D printing

What can JNCTURE make?

JNCTURE is suited for medium to large polyhedral objects of high complexity, where other modes of fabrication might be difficult or time intensive. JNCTURE is ideal for creating large sculptural works, prototypes, and models. JNCTURE’s designs are not automatically suitable for load bearing usage. Designs for load bearing structures can be created using JNCTURE, but must be optimized by the designer. Additionally, the limitations of the user’s own 3D printing technology must be considered and factored into their own designs. Future iterations of JNCTURE will include tools for stress analysis and part optimization to account for some variation in home 3D printing capabilities.

Design for Playground Structure created in Rhino using JNCTURE