Tobold's Blog
Sunday, January 05, 2020
3D Printing Gravitrax

I don't currently have a working 3D printer; but my old printer is in the shop for repairs, and I also ordered a new second printer, seeing how often the first one is out of order. Now home 3D printers are a solution in search of a problem: Most people simply don't have all that many useful things they could print in 3D to make buying a printer really viable. So I am quite happy to have found a new 3D printing project: The Gravitrax marble run system.

I bought a Gravitrax marble run starter set and two expansion boxes for my brother and his children, as a sort of "fun for the whole family" additional Christmas present. That was quite a success. The system has a base plate with hexagonal holes into which you put hexagonal flat pieces, connected with rails. There are stackable hexagonal pieces to achieve height, so the rails can slope downwards and accelerate the metal marble, giving it the energy it needs to cross the flat parts. The whole system is very modular, and if you search for Gravitrax on YouTube, you will find some people who made really huge marble run tracks with all sorts of tricks.

Now the starter set costs $60 for 122 pieces, or 50 cents per piece. Special pieces, like a box with a looping and 6 rails, cost $10. And once you get building, you will quickly want more pieces. So while I hadn't thought of it when I bought the starter set, once I played with it I quickly realized that I could print these pieces. Getting me exactly the pieces I want, and for less money. Plus it turns out that people have designed Gravitrax compatible pieces as 3D prints that aren't available to buy, from the simple straight line hexagon, to the U-turn piece.

So once I have a 3D printer up and running again, I have a project for printed pieces. I bought another Gravitrax starter set for myself, in order to be able to test my printed pieces for compatibility before giving them to my brother. While the hexagon pieces are only 6 cm in diameter and thus of an ideal size to print for a typical home 3D printer, there remain some challenges. A marble run works best with minimal friction, and I suspect that the surfaces of 3D printed parts won't be as smooth as injection molded ones. Maybe if I print in ABS and then smooth the surface with acetone vapors, I can get friction-less parts.

The legal side of this project is a complete mystery to me. If I print stuff that is compatible with Gravitrax, but not an identical copy to something I could buy, is that copyright infringement in any way? As long as I don't start a business selling the pieces I am unlikely to run into any trouble, but I find the question theoretically interesting. 


You should be safe enough, but people generating blueprints for Gravitrax-compatible 3D prints and publishing them might get in trouble, I reckon - if they use the name Gravitrax anyway.

Of course it's possible that the makers embrace this - they might even reckon it will bring them more custom.
> the starter set costs $60 for 122 pieces, or 50 cents per piece.
> Special pieces, like a box with a looping and 6 rails, cost $10

Here you go: microtransactions in the real world. And modding (when you use your printer to build new stuff).
How you handle rails? Based on other similar games, it's first you need in numbers...
The Gravitrax original rails are made out of plastic, so it should be possible to 3D print them. Question is only whether they are smooth enough to work well.
Post a Comment

<< Home
Newer›  ‹Older

  Powered by Blogger   Free Page Rank Tool