YOU CAN BUILD A PLATE THAT TURNS SOUND INTO PERFECT SAND PATTERNS
Sprinkle sand on a metal plate, play a tone, and watch chaos snap into perfect symmetric figures — 240-year-old physics you can build in an afternoon.
by Aron Hoekstra (guide) / Ernst Chladni (physics)
SciencePhysics
- difficulty
- ●●○○○
- time
- an afternoon to a weekend
- license
- not specified
- repo
- repo STUDENT PROJECT; GUIDE LIVES ON INSTRUCTABLES1 stars
●●○○○ · an afternoon to a weekend · not specified · 1 stars · repo STUDENT PROJECT; GUIDE LIVES ON INSTRUCTABLES
Partner
COMPAREE VERDICT
This is the simplest build we have catalogued, and one of the most mesmerising: a steel plate sprinkled with salt, driven by a tone, and the grains leap into symmetric figures along the silent nodal lines — Ernst Chladni's 240-year-old experiment, running on your coffee table. We will be straight with you: there is no GitHub project here. The definitive guide is a 6-step Instructables by a dad whose son took first place at a science fair with it, and its central insight is what NOT to do — do not tear apart a speaker to make a 'wave driver' (he ruined one trying). Instead an unmodified subwoofer pushes a threaded rod that carries the plate. A computer tone generator does the rest. If you want the electronics version, a Brazilian engineering-school team published amplifier schematics and Arduino firmware — including the lesson that a little LM386 module physically cannot shake the plate hard enough.
IN THE REPO
NOT IN THE REPO
- —Honest up front: there is NO real open-source repo for this build — it is a classic physics demonstration, not a maintained project
- —The best build guide is on Instructables (6 illustrated steps, complete parts list in step 1) — that is what our page follows
- —The only GitHub hardware attempt we found is a Brazilian student project (IFSP São Paulo) with amplifier schematics, PCB layouts and Arduino firmware — but it declares no license
- —The ~300 'chladni' repos on GitHub are all software simulations of the patterns, not build plans
- —No 3D printing involved — this is sheet metal, threaded rod and a subwoofer
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
Videos
Chladni Figures — random couscous snaps into beautiful patterns3:50
Steve Mould's demo — the clearest explanation of why the grains find the silent lines.
Gallery
Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Follow the Instructables guide (6 steps with pictures; parts list in step 1)
- 2.Watch Steve Mould first (you will understand what you are building)
- 3.Use an online tone generator (the guide's own recommendation — no electronics needed)
- 4.Electronics route: the IFSP repo (amplifier schematic, PCB, Arduino DDS firmware — no license declared)
- 5.More background: the Make: article (the classic wave-driver approach (harder))
Resources
Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.
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KNOWN ISSUES
- Do NOT dismantle a speaker to build a 'wave driver' — the guide's author ruined one and never got it working; his whole design exists to avoid that
- Plate thickness is critical: too thin sags and the salt slides off; too big is too heavy to vibrate — around 18 inches square hit the sweet spot
- Start with the volume LOW — too loud and all the salt jumps straight off the plate
- There is no universal magic frequency — it depends on your plate's material and size (the guide found 80–250 Hz; the IFSP team's smaller plate resonated at 190–340 Hz). Sweep slowly and watch
- The rod-to-speaker joint is the weak point — tape worked on a hard plastic cone; soft paper cones need another approach
- It gets messy — put the whole rig in a large box lid before you pour the salt
Why does the sand form patterns?
The tone makes the plate resonate in standing waves. Most of the plate vibrates violently and throws the grains around — but along the nodal lines the plate stands still, so the grains settle there. The pattern is literally a map of the silence.
Is there any open-source repo for this?
Not really, and we checked hard: ~300 GitHub 'chladni' repos are pattern simulations. The one hardware exception is a Brazilian student project (IFSP) with amplifier schematics and Arduino firmware — useful, but it has no license. The real guide is on Instructables.
Does it have to be salt on steel?
No. Salt, fine sand and cornmeal all work (the IFSP team lists all three), Steve Mould uses couscous, and the plate can be steel or even polypropylene. You just need fine grains with good contrast — spraying the plate black helps.
Can I drive it from an Arduino?
Yes, but not naively: the tone() function makes a harsh square wave, and a bare LM386 module is too weak to form clear patterns. The IFSP project solved both — a DDS sine generator on the Arduino plus a ~1.5 W class-AB amplifier, with schematics and firmware in their repo.
Community builds
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Discussion1
FROM THE COMPAREE TEAM
No repo, no firmware, no printer — just a plate, a tone and physics from 1787. Does a build this simple still count as a project to you, or is the best kind exactly this?
You can build a wall of 80 steel balls that float and ripple like liquid metal
●●●○○ · another mesmerising physics display, much bigger build
You can build a wall of liquid magnet that draws animations in mid-air
●●●●○ · liquid instead of sand, electronics instead of tones
You can build your own floating ring of plasma in a glass sphere
●●●●○ · the high-voltage end of beautiful physics
Aron Hoekstra (guide) / Ernst Chladni (physics)
A dad and his son built the definitive easy version for a school science fair — first place — and wrote down every mistake, 240 years after Chladni first bowed a sand-covered plate.
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DISCLAIMER
- Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM1mo ago
Honest note from our research: we searched about 300 GitHub repositories for this one and found no real open-source build — they are almost all pattern simulations. The definitive guide turned out to be a 6-step Instructables by a dad whose son won a science fair with it, and its core advice is what NOT to do: never tear a speaker apart for a wave driver. The one hardware repo we did find is a Brazilian engineering-school project with a proper class-AB amplifier design — including the measurement of why a bare LM386 module is physically too weak to form clear patterns.