About STEMFIE
STEMFIE is a free, open-source construction toy for the age of home 3D printing: thousands of parts that all fit together, made on your own printer, whenever you want them.
What it is
STEMFIE is a construction set in the classic tradition, beams, braces, plates, gears, wheels, screws, and nuts, with one difference: nobody sells you the parts. You print them. Every part follows one open geometric standard, the STEMFIE Standard, so any two parts fit, whoever designed them and whenever they were printed. The files are free, the standard is free, and both will stay free.
It was made to share a love of technology and science with children and schools everywhere. The idea is simple: a child who prints a part, builds a machine, and sees it work has learned something no screen can teach. Learning by building is what STEMFIE is for.
How it began
In 2015 I co-created 3DBenchy with Daniel Norée, the little boat that became the standard test print of the 3D-printing world. What struck me was not the boat itself but how easily it spread: at a time when far fewer people had a printer at home, thousands of Benchys were being printed everywhere, from a single file. I wanted to make something that could travel the same way, but that added to what you had already printed. A fleet of identical boats is fun once. A construction set is different: every new part makes every old part more useful.
I had grown up building contraptions with my father from a metal construction set of the kind sold since the early 1900s, all strips and nuts and bolts, and I still had it at home. I remember those hours vividly, inventing a machine from nothing and watching it come to life piece by piece. Today I understand how much those afternoons shaped me. So the choice of what to make was easy. The first STEMFIE parts, in 2018, were beams and plates in that spirit.
The real work was the size. A construction set needs screws and nuts, and the scale of a printed thread is set by how accurately a consumer printer can make one. Too small and the threads do not hold; too large and the toy is no longer a toy. The early parts were built on 12 mm. Having worked in product design most of my life, I was at home in both the metric and the imperial systems, and in the imperial habit of halving and doubling, and I found myself drawn to 12.5 mm: metric, but halvable all the way down, and eight of them make exactly a decimeter. That became the STEMFIE Unit, and every part since has been a fraction or a multiple of it. STEMFIE is metric, but it thinks in halves.
The first parts went online on 21 December 2019 and the first kit, a rubber-band-driven car, on 2 January 2020. Since then the system has grown to thousands of parts, and to kits, teaching material, and a community of builders in many countries. I gave the standard and all the parts away from the start, because I knew children would enjoy printing the parts as much as building with them, and because a standard is only worth something if everyone can use it.
Paulo Kiefe, creator of STEMFIE
Milestones
- 2015
- 3DBenchy is released and spreads worldwide. The idea of a printable construction set takes shape.
- 2018
- The STEMFIE Unit is set at 12.5 mm; the first beams, screws, and nuts are designed around it.
- 21 Dec 2019
- The first STEMFIE parts are published for free download.
- 2 Jan 2020
- The first kit, the Rubber-Band-Driven Car, is released.
- 2020 – 2025
- The catalog grows to thousands of parts; kits, tools, and teaching material follow, and STEMFIE parts are printed by makers, families, and schools around the world.
- 2026
- The STEMFIE Standard is formalized and stemfie.org is rebuilt around it.
Who is behind it
STEMFIE is created and maintained by Paulo Kiefe, a product designer based in Sweden, with contributions from a community of designers, teachers, and makers. The project is independent and funded by its supporters; see how you can help it grow.
STEMFIE is open all the way down. Every part is designed in FreeCAD, visualized in Blender, and illustrated in Inkscape, all free and open-source software. The choice is deliberate: a child, a teacher, or a designer anywhere can open the same source files with the same tools, at no cost, and carry on where the project left off.
Contact
Questions, ideas, teaching enquiries, or partnership proposals: write to paulo@stemfie.org.
⚠️ Contains small parts that are a choking hazard. Not suitable for children under 3. Suitable for ages 3 and up under adult supervision.