Marble Fountain

https://willmorrison.net/posts/marble-fountain/

by chris_overseas • 9 months ago

895 92 9 months ago

willmorrison.net

matthewfcarlson• 9 months ago

This is absolutely brilliant

dbacar2• 9 months ago

"ramble about marbles"

nice one!

scubbo2• 9 months ago

A pun? I don't get it, could you explain?

jwiz• 9 months ago

Anagram, perhaps.

dbacar2• 9 months ago

I meant same letters, ramble -> marble

xnx• 9 months ago

Stupendous project and video as well! The music is very complementary.

neomantra• 9 months ago

Amazing on so many levels!! Thank you also for including the source.

Levitz• 9 months ago

Mesmerizing and beautiful in a simple way, I really like this type of thing.

foltik• 9 months ago

Be sure to turn on sound for maximum mesmerization.

CGMthrowaway• 9 months ago

Mesmerizing is the right word. "I can watch them for hours" was the key bit for me - I have always been fascinated how humans can stare at a random visual generator for forever, if it's the right one.

I think there is an instinct built deep in our lizard brain somewhere for this. Humans will happily stare at a fire, or an ocean, or a wave in a river, or (sometimes, especially children) a TV screen - and all I have worked out why is because it is constantly changing in an unpredictable way.

This marble run shouldn't even be unpredictable - clearly the paths are fixed and the cadence of balls is regular - but somehow it is still mesmerizing.

ecountry• 9 months ago

This is magical. Thanks for sharing!

wxce• 9 months ago

Beautiful, I wonder what kind of craziness would be possible with this, at scale. Whole buildings being printed and assembled block by block. Real life Minecraft, if you will

temp0826• 9 months ago

Are procedurally generated rollercoasters a thing?

sergiotapia2• 9 months ago

Blame! is a manga where in the future humans have robots that build, and are controlled by people with Net Terminal Genes. Something happens and those humans die leaving the robots building non-stop procedurally for eons. By the time our protagonist moves about in the world, its said the Megastructure reaches from Earth all the way to Jupiter.

Also, the movie Fracture features these cool marble machines. https://www.youtube.com/watch?v=Y-v6E9H6nh0

Back when movies were made with unique good scripts and not marvel slop.

stavros3• 9 months ago

Where did they get the material for it?

9dev• 9 months ago

There are serious efforts and working prototypes of printing houses. This works surprisingly well, allows construction in days instead of months, and shows a lot of promise. It’s a great rabbit hole to fall into!

IshKebab• 9 months ago

Does it though? I have yet to see a 3D printed house that would be cheaper than SIP panels.

lloydatkinson• 9 months ago

I wish there was a write up of how some of the code works. There's a lot of Python in the repo. Looks fascinating, seems to use Python to generate OpenSCAD code, I think.

WillMorr8• 9 months ago

It's specifically using SolidPython2 to generate the models. I originally wanted to do a quick code cleanup and have the specific math be much clearer but by the time it was working that was an absolutely massive undertaking. If I touch the code again I'm probably going to refactor the entire codebase and use a different 3D engine.

fogleman• 9 months ago

What did you not like about the SolidPython2 / OpenSCAD approach? What would you want from a different "3D engine" for this?

CasperH2O3• 9 months ago

Have you considered Build123D for CAD code?

I am also procedurally generating marble tracks and 3D printing them for about a year now and found that library very useful.

The community is very active and its very similar to features we know from Fusion360/SolidWorks but all in code.

collingreen• 9 months ago

This is cool! Great job on the video - Simple voiceover, synced music, and the fountain speaks for itself. Bravo.

MomsAVoxell• 9 months ago

This is beautiful. It would be amazing to have the tracks encode/decode audio, you know? Like, the track of the marble can be used to generate different frequencies...

amenghra• 9 months ago

There's a Tom Scott music about a musical road in California: https://www.youtube.com/watch?v=Ef93WmlEho0

WillMorr8• 9 months ago

I actually attempted this, the idea of a python script that converts a midi track into a marble run is just too good to not try. I printed a large drum with different track structures inside so I could test various "slopes" by changing the speed and it just doesn't work, the balls bounce around too much to get an audible pitch. A less rigid material or a larger bearing would likely work better but I decided to focus on getting the normal version working well.

smusamashah• 9 months ago

Did you try changing thickness of rails instead of bumps to produce different sounds?

m_kos• 9 months ago

I am not surprised you tried given your earlier project :) https://hackaday.com/2022/09/25/this-found-sound-organ-was-m...

Maybe at the bottom your marbles could land on surfaces with different accustic properties. Track selection would determine the surface and release time would determine the timing.

aitchnyu• 9 months ago

Is the banking of the curve for a specific velocity?

stevage• 9 months ago

It says that the banking is intentionally excessive.

LandStander• 9 months ago

This is a great example of a good use case for 3D printers. The smooth marble run action combined with the interwoven organic forms would be a huge PITA to fabricate with any other method I can think of, even if your just making one.

stavros3• 9 months ago

A good use case for 3D printers is random, small, custom household items that greatly increase my quality of life, much more than it is a unique sculpture.

cissou• 9 months ago

What printer do you use for that and are you happy about it?

deaux• 8 months ago

Really curious to hear a few of these!

eschluntz• 9 months ago

Very cool! I've designed a lot of Hilbert Curve marble tracks, using OpenSCAD and python

WillMorr8• 9 months ago

That sounds super interesting, do you have a link?

gaudystead3• 9 months ago

Not the person you asked, but look up "Hilbert Curve" on Thingiverse, Printables, or Thangs and I bet you'll find somebody who uploaded a marble run with more information for you.

CasperH2O3• 9 months ago

Small world, I opted for a Gosper curve myself, but when it got too big, cut out specific pieces and connected those.

It gives everything a uniform look while allowing to fill the space in a different way.

fHr• 9 months ago

so cool!

CasperH2O3• 9 months ago

This is really quite interesting and similar to a project I'm working on. I've been using procedural generation to generate a marble dexterity track similar to a Perplexus. My tools are mainly Python, the Build123D library and a 3D printer.

cyrusradfar• 9 months ago

I appreciate the work. It's really beautiful and checks so many of my "oddly satisfying" boxes as a builder. It seems it hit those for you too, obviously.

Separately, the timing of seeing this is uncanny. I've been using marble runs to explain probability to my kids and was filming a marble run conversion lesson. Seeing this at the top of HN felt like someone was reading my minds.

TealMyEal• 9 months ago

I would pay silly money for one of those things on my desk

rwmj• 9 months ago

Is it printed / sintered in metal?

hinkley5• 9 months ago

Looks like fiber infused filament.

randyrand• 9 months ago

I wonder if you could get it to run silently, or close to it.

hinkley5• 9 months ago

That guy who makes marble music recently worked out a ball funnel that uses inserts in a different material to eat most of the noise. But in that case it’s also eating momentum as well so I’m not sure how that would work for this design. Maybe some bushings in the supports to reduce harmonics.

bigiain• 9 months ago

Now my brain is doing it's usual "over complicate things to the extent a project cannot possibly get started" thing"...

Active noise cancelling. Vibration detectors on oscillating parts of the track with LRAs or similar actively driving opposing vibrations. Might be able to use whatever the cheap active noise cancelling electronics headphones have? Might be able to use a high speed camera and video motion amplification to work out the best places to deploy it?

kazinator• 9 months ago

Designers of marble fountains who don't use computing to design the paths run into reliability issues: sometimes balls derailing out of their track. They have to observe the contraption, identify problems (balls getting jammed up or jumping out) and then guess at the root causes and make manual adjustments.

That's the thing here: he has it running for hours presumably without any ball jumping out.

Most of the tracks consist of two rails, so the ball has two contact points. I'm no physicist but it seems like the goal would be to have ideally nearly equal forces at the two contact points at all times during the ball's descent. In other words, the track has to be perfectly banked so that the gravity and centripetal acceleration vector are balanced by a normal vector perpendicular to the rails. During a derailment, the ball has to lift away from one of the two contact points, so the normal force must have dropped to zero.

WillMorr8• 9 months ago

It's actually much weirder than that: banking changes the axis of rotation and thus kills the rotational inertia. The tracks bank super aggressively in order to prevent the ball from accelerating too much and hopping the track. This is part of why the descent is so smooth and all the balls move at more or less the same speed.

Also to be fair the final system does lose a ball every 30ish minutes. The tuning was largely me staring at the run or taking a video trying to catch where they get lost. Instead of hand tuning I would just update the generator and print another one. I'm considering closing the loop with a camera but that would be a whole new project.

sixtyj3• 9 months ago

For roller coasters there is a software for simulation. It is imho similar situation compared with balls in your Marble Fountain

https://www.nolimitscoaster.com/

First, I thought about Ansys or CATIA software but I couldn’t find any module specialized for simulation of balls.

But I think that people from those companies could help as well and participate in simulation as an interesting usecase. (These software are expensive for personal projects.)

adzm• 9 months ago

Does the temperature of the track change much after thirty minutes?

rendall• 8 months ago

Could (or do) you include a catch basin at the bottom to automatically return the odd errant lost ball to the queue?

hdjrudni• 9 months ago

That's the thing here: he has it running for hours presumably without any ball jumping out.

You can see a ball on the ground at the end of the video :-)

ljsprague3• 9 months ago

My naïve guess would be that you can't change the route of the ball without asymmetrical track pressure.

rjmill• 9 months ago

Not to dimish the achievement, but TFA is pretty clear about the limitations of the piece:

I was able to get it working consistently, although it did lose 2-3 balls an hour and could only run for a few hours without the motor overheating.

IMO that's more impressive to hear than if he hadn't mentioned it at all. (I would have assumed more marbles getting lost.)

fho• 8 months ago

Just nitpicking, but there is at least one ball next to his contraption in his video :-)

Doesn't make the whole thing less remarkable.

jjcob• 8 months ago

You are missing inertia!

The state of each ball can be described by 9 parameters: the current location of the center of mass (x,y,z), the current linear velocity (vx, vy, xz) and the angular velocity on 3 axes.

I don't think the forces acting on the rails need to be similar -- they just need to be such that the acceleration of the ball is always parallel to the track. Unfortunately the equation of motion will look pretty ugly and optimizing the system will be quite a challenge.

And finally, the system has to be stable, ie. small perturbations should be cancelled rather than grow - if a ball gets a little too fast there should be something like a bend that slows it down, but that bend should at the same time not slow down a ball that is already too slow...

there4• 8 months ago

Another parameter - as a track designer you can manipulate the width of the track to change the ball speed. It raises and lowers the ball on the track, changing both the rolling diameter and the center of gravity. This can be used to make subtle changes to the ball speed before a turn.

hinkley5• 9 months ago

Maybe it’s the color and this would look better in a brighter shade, but I hate it. It looks wrong. Malignant.

hinkley5• 9 months ago

I bet this would look baller with green rails and brown supports. Also might help with losing the balls visually as they get to the bottom. The visual noise makes them harder to track.

underdeserver• 9 months ago

It looks like Bones from Hades 2. Beautiful, and super cool.

bix6• 9 months ago

Super cool! I would love to see a white / clear one with LEDs. Rainbow road :)

Taek• 9 months ago

White/clear is just a matter of picking filament, I'm not sure LEDs would be easy to incorporate into the build

WillMorr8• 9 months ago

I've actually done clear prints with LEDs installed. The bottom is much brighter than the top and it just look kinda tacky. I briefly hollowed out the supports and tried running fiber optics but it didn't help much.

I'm realizing now that I tried a lot of weird shit during this project that just did not work at all or make it into the final product, I should do another video just of all my failed abomination marble runs.

gaudystead3• 9 months ago

Please do! Also just some footage of the machine running from specific angles for a few minutes would be lovely! Nice work! :)

timmg2• 8 months ago

Minor suggestion/request: would be great if you added a final STL file to the github repo of a working example. Might be easier for people to try if they can't get the python code running on Linux.

(I haven't tried yet. But I'd love to just send an STL to my printer to see how well it prints.)

ashepp• 9 months ago

Stl?

titanomachy• 9 months ago

The particle simulation approach to generating an organic "tree-like" support structure is super creative! If I'm understanding correctly, you defined some laws of physics and then ran a simulation with the "time" dimension mapped to the z-axis? Is this a well-known approach, or something you came up with?

Either way, it produces a beautiful aesthetic. I'd love to play around with this idea.

WillMorr8• 9 months ago

That's pretty much it! It's the simplest method of supports I could come up with that allows for robust keepout zones. I did have a bunch of issues at first with supports blocking the path but with a little tuning it became surprisingly consistent. I doubt I'm the first to come up with it but I have not seen any similar systems.

Thank you! The emergent forms are much more interesting than they have any right to be for such a simple system.

froh• 9 months ago

The emergent forms are much more interesting than they have any right to be for such a simple system.

hehe I wonder if this is how evolution in nature "comes up with" beauty :-D

ljsprague3• 9 months ago

Gorgeous!

ljsprague3• 9 months ago

Why isn't the top-down footprint a square?

codr7• 8 months ago

Up next: https://www.youtube.com/watch?v=IvUU8joBb1Q

3oil3• 8 months ago

Just wow.

ch_fr• 8 months ago

Awesome project, I love to read about all kinds of different procedural generation approaches!

worldmerge• 8 months ago

Will this is incredible! I’ve been learning openscad and making 3d models with it using python and this is such an inspiration. Check out the latest nightly version of openscad it’s significantly faster, like seconds vs multiple minutes on my exports.

frenchie4111• 8 months ago

This is awesome! I'd love to print one for my office. Any chance there is an stl around I can print without having to get the script running?

chrisofspades• 8 months ago

!play

Marble Fountain

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