Part Design Suggestions

Trikka Part Design Suggestions 

Vs. 1.0

A couple of things we suggest to consider when making Trikka parts – they are suggestions, not requirements.


Trikka Grid

30mm 3grid

Trikka is inspired by erector sets. Erector sets are modular toys where all parts can be connected to each other with nuts and bolts. The parts are multi-use. This works because the distance between the holes are the same in all parts. All parts are based on the same grid. Trikka tries to make this magic happen for its parts as well. The grid of Trikka uses a 30mm distance between the holes (or multiples thereof like 60mm, 90mm, 120mm etc. or for small parts half steps toward zero 15mm, 7,5mm). Whenever you add holes try to stay within this Grid. This will increase the likelihood of creative reuse of your parts by others. Some designers see this grid as a relief because it allows for quick decisions about how big or small something is. More about universal grids for everyday products and the origin of the 30mm-grid of Trikka you can read here & here.

Meccano, Eitech, Lena are some brands for metal versions of this
BILOfix, Baufix, Brio Constructor are some brands for wooden versions; img by E. Poulsen, cc-by-sa
Different parts with holes based on the same grid. It is obvious that unlike the toys not every possible hole is drilled, just the ones needed in this part.
All parts of Addi the chair are based on the 30mmm Trikka grid. It was a challenge to find a design where the Trikka grid makes a comfortable chair. But it was worth it. The parts are also useful for several other things.



Trikka aims to enable local repair, make and reuse. That’s why many parts in the catalogue are flexible when it comes to the choice of materials and also dimensions. Ideally Trikka parts can be made from a variety of materials using simple tools and still work in most designs.

The standard tolerance allows a size deviation of +/- 15mm from the values mentioned in the parts post. “Strong” material for example includes wood, metal or solid plastic but not bendable foil or foam.

Not affected by the tolerance is the number, position and diameter of the holes!

These are two different parts. The dimensions are the same and the holes are in the same location, but the holes are different in size.

These are the same parts. The dimensions are slightly different but the location of holes relative to each other and their diameters are exactly the same.

The same part executed in different materials and with small deviations in shape and size. Open Shelve Nodes by Mifactori.

Tolerance may lead to cases where a part does not work in a design with that part (for example when the material is too weak or an uneven surface does not work). Le’s see if this really emerges and how big an issue it will be. Trikka is open research. Research with us.

The five parts above are all individual parts. Holes are the most important way in Trikka to connect different parts. Therefor they need to align. We know that it is possible to modify parts for example by adding holes, enlarging them or cutting parts off. Or that you swap them (for example part 1 and 3 in the image above). And also that you can combine smaller parts into one larger part. Currently we can’t show this to avoid unmanageable complexity. But eventually this will be addressed in the future.

The tolerance rule explains why bolts come in these steps:

10 – 30 – 50 – 70 – 90 – 110 – 130 – …

+/- 15mm allows to have all steps in between – for example 14mm. 

heads of bolts are free to chose (tolerance)

“Makes” ?

A Trikka design-solution is a collection of open parts and a way to assemble them. Because there is a tolerance as to what materials parts are made of and what colour they are, there is not one final version of a Trikka design. When a Trikka design is made – turned into atoms – final decisions regarding colours, materials and even shapes are made. Different makers will get different results. But they all made the same Trikka solution – ideally you can disassemble them and swap parts between them. 

To understand this better make sure not to miss what is said above about ↑ tolerance.

If you want to understand this better read here: “What is the final version in Open Circular Design?”