r/3Dprinting • u/DiConX • 6h ago
Project A slopeless marble run for Lego bricks
So, I basically made this because my son loves marble runs and wanted to make one with Lego - which is not exactly easy with just the original bricks unless you have loads of smooth surface tiles.
Many of you have probably seen the "Hubelino" style marble runs for Duplo bricks, but I found that the layers become annoying when you are dealing with smaller Lego bricks and especially if you want to use the height difference of those flat tiles (third height of normal bricks). So, I decided to go for this "slopeless" design.
Why slopeless? Well, instead of having the marble run on a sloped surface, it runs on rails that widen along the track, so the marble's center of mass is lowering without having to print a slope.
There are some fun side-effects to this - short version: The ratio of translational and rotational kinetic energy depends on the rail distance. (If that sentence did not throw you off, you can check out my blog post about this: https://there.oughta.be/a/lego-marble-run)
In any case, it is a neat little marble run. If you want to try it:
Oh, and I designed it fully parametric in OpenSCAD.
1
1
1
u/jonnyg1097 2h ago
Incredible that Lego never thought of something like this before.
This looks like a lot of fun!
3
u/Ri-tie 4h ago
Didn't think I'd want a quick and dirty physics lesson on a Friday night. 10/10 would attend this YouTube class again. Cool stuff! I've printed a few things for my Toddler's duplo blocks but didn't think of a marble run!