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Marble Fountain

willmorrison.net

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Re: Marble Fountain

#41

Post by sixtyj »

WillMorr wrote: post #35
kazinator wrote: post #29

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…

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 largel…

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.)

Re: Marble Fountain

#42

Post by djmips »

sixtyj wrote: post #41
WillMorr wrote: post #35

Earlier quoted context omitted.

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 largel…

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 ex…

Well except for this is SIM only whereas the OP (WillMor) is making them for real with a 3D printer!

Re: Marble Fountain

#43

Post by bigiain »

hinkley wrote: post #31
randyrand wrote: post #25

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

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.

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?

Re: Marble Fountain

#44

Post by IshKebab »

9dev wrote: post #28
wxce wrote: post #9

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

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!

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

Re: Marble Fountain

#45

Post by WillMorr »

MomsAVoxell wrote: post #14

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...

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.

Re: Marble Fountain

#46

Post by hinkley »

bigiain wrote: post #43
hinkley wrote: post #31

Earlier quoted context omitted.

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.

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 amplificati…

How you mount things matters a lot, and adjusting shapes to prevent harmonics might be something this guy could add to his algorithm.

I saved a couple friends in college from getting into fights with their downstairs neighbors by finding them milk crates to set their speakers on so the bass doesn’t all end up in the floor. Isolating from the base or making the base of TPU could likely help.

Re: Marble Fountain

#47

Post by hinkley »

hinkley wrote: post #30

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

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.

Re: Marble Fountain

#48

Post by smusamashah »

WillMorr wrote: post #45
MomsAVoxell wrote: post #14

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...

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…

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

Re: Marble Fountain

#49

Post by sixtyj »

djmips wrote: post #42
sixtyj wrote: post #41

Earlier quoted context omitted.

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 ex…

Well except for this is SIM only whereas the OP (WillMor) is making them for real with a 3D printer!

My point was that these software could help to find weak parts in trajectory - so instead of trying to figure it out by looking where balls are too quick to fall from the ride - you can simulate it. I saw real tramway simulation done in Ansys.
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