Free Universal Construction Kit

Free Universal Construction Kit is a collection of open source 3D-printable adapters that facilitates and enhances creative play by enabling "interoperability between ten popular children's construction toys.”^[1]

Free Universal Construction Kit by Golan Levin and Shawn Sims (detail of "Universal Adapter Brick")

Overview

Examples of pieces printed "in the wild" by end users (2013)

The Free Universal Construction Kit (F.U.C.K.) was developed at Carnegie Mellon University by Golan Levin and Shawn Sims in 2012.^[1] The open source project was conceived to facilitate play by allowing for interconnectivity between unrelated and otherwise incompatible toy construction sets. It is a "matrix"^[2] of reverse engineered 3D-printable adapter pieces that permit Duplo, Fischertechnik, Gears! Gears! Gears! [d], K'Nex, Stickle Bricks (a.k.a. Krinkles Bristle Blocks), Lego, Lincoln Logs, Tinkertoys, Zometool, and ZOOB [d] to be easily assembled with each other.^[3][4][1] The inspiration for the project came from Levin's observations of his own young son's frustration with the difficulty he experienced in attempting to connect pieces from these otherwise exclusive, incompatible, and closed-loop toy systems.^[5][6]

The F.U.C.K. system, as described by the designers, is a "grassroots interoperability [remedy]" that "implements proprietary protocols in order to provide a public service unmet, or unmeetable, by corporate interests."^[2][7][8] It includes approximately 80 individual pieces which were engineered and modelled using micrometre precise data (less than .0001 of an inch) gathered by taking optical comparator measurements of each of the construction toy systems included in the kit – ensuring that the custom pieces and commercial components fit snugly together without alteration, special tools, adhesive tape or glue.^[2][5] Most of the individual pieces allow the user to connect two systems (e.g., Lego bricks ⇆ Lincoln Logs, Lincoln Logs ⇆ Tinkertoys, etc.),^[6] however, the matrix also includes a "Universal Adapter Brick" that integrates the connectors of all ten of the referenced construction sets into one single larger element.^[4]

A library of stereo lithograph printing files (a.k.a. STLs) of the Free Universal Construction Kit 3D models is available to be freely downloaded from a number of online sources.^[9] These files can be used to reproduce the pieces in a number of materials with a variety of 3D manufacturing devices and technologies.^[1][5]

Reception

Free Universal Construction Kit, Ars Electronica, Offenes Kulturhaus [de] museum, Linz (2012)^[10]

The Free Universal Construction Kit was exhibited during the 2012 edition of Ars Electronica in the Offenes Kulturhaus [de] museum in Linz, Austria. It received the Ars Electronica Award of Distinction.^[10] It has also been exhibited at Node Forum for Digital Arts in the Künstler Mousonturm [de] in Frankfurt am Main; Fundacin Telefnica, Madrid, Spain; BOZAR Center of Fine Arts, Brussels, Belgium; Kunsthaus Pasquart [de], Biel/Bienne, Switzerland; London Design Museum; Miller Gallery, Carnegie Mellon University; Gray Area Foundation for the Arts, San Francisco; Center for Bits and Atoms at MIT's Media Lab in Cambridge, amongst other venues.^[2][11]

The F.U.C.K. system is in the collection of several museums, including the Cooper Hewitt, Smithsonian Design Museum, and the Museum of Modern Art (MoMA) in New York.^{[3][5][12][13]} It was also included in MoMA's 2025 exhibition, Pirouette: Turning Points in Design,^[14] featuring "widely recognized design icons [...] highlighting pivotal moments in design history," such as the Bean Bag chair, the Sony Walkman portable cassette player, the NASA Worm insignia, and the Gay Pride flag.^{[15][16][17][18]}