Show HN: I spent 6 years building a ridiculous wooden pixel display
391 benholmen 63 8/4/2025, 4:16:21 PM benholmen.com ↗
I built the world's most impractical 1000-pixel display and anyone in the world can draw on it. It draws a single pixel at a time and takes 30-60 minutes to complete a single image. Anyone can participate in the project by voting for the next image to be drawn, and submitting images.
Mine was entirely mechanical (driven by punch cards and a hand-crank), and changed all of the pixels in parallel, but a lot of the mechanism development looked extremely familiar to me.
I was recently in the presence of some linotype machines from the 1800s and it's so good to be humbled by the achievements of people who came before us. That machine was so complex, I could barely begin to figure out how to manufacture one. Your discussion of looms reminds me of that!
https://en.wikipedia.org/wiki/Calm_technology
A few suggestions for improvements:
- After completing a submission, move the "pen" out of the way as much as possible to get a clean photo of the completed art before moving onto the next submission.
- On the website, show attribution for the currently in-progress submission.
- On the website, have a "history" gallery for completed submissions. It looks like pending submissions have permalinks that say "Timelapse will be available after this is drawn", but there's no way to discover permalinks for completed submissions (or the in-progress one).
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With the most cost effective and creative "wear item" ever.
I found a blog post about it and someone who made one with a servo for each pixel. Now that would be expensive!
https://differencing.blogspot.com/2010/04/kinotrope-clackers...
Has there ever been designed a "display" that is just a thermal printer hidden in one end of a box, and a take-up spool + tensioning spring hidden on the other end, such that the "display" is then a continuous thermal paper "scroll" stretched across the box behind [UV-protective!] glass, that can be "refreshed" by printing a new full-width image to the thermal printer?
This ink is interesting in that it fades when heated (60 C), but darkens when cooled (-10 C). In between those temperatures it is stable.
Thus you could have one loop that is continuously reused. Not sure how many cycles you can get before the ink degrades.
What about some system to shoot wooden spheres into a tube or channel for each scan line, selectively feeding different color spheres. Some combination of gravity or pneumatics to drive it. So a scan line would flush out one end and refill from the other. Then scale it up to a stadium size unit with bowling ball pixels.
I guess a challenging part would be proper timing to recycling the colors back into their appropriate supply channels. And also introducing some kind of damping to quiet it down and reduce the wear and tear on the pixels.
On the other extreme, you could go active matrix and have blocks that simply rotate in place to show different face colors based on some solenoid/servo action.
"Motorized pin art display" is what i'm going for...
The problem with passion projects: Progress is never as much or as fast as I want, though! Hard to find the people who want to throw money at things like this and/or buy them. And anything mechanical gets complicated and expensive very quickly. But it's so much fun and a great way to learn and apply so many new skills: laser cutting, 3D printing, CNC milling, circuit design, embedded programming, etc.
[1]: https://youtu.be/tx4W3ZDA_Vg
- naively: Levenshtein
- better: real world edit time based on a model of the display : probably dominated by XY travel distance
Given the current image being shown and the next image, you (presumably) want to plot the pixels of the next image as quickly as possible. I believe the optimal algorithm is:
1. Calculate the set of pixels that are changed between the current and next image.
2. Find the shortest path from the plotter's current position through each of those pixels. I believe breadth-first search (O(n)) is sufficient here.
Running this on all potential upcoming images and choosing the one with the lowest total path cost would do what you propose under "better".
> I have a mechanism to quickly delete problem submissions.
Did you build a male genitalia swastika classifier like the fish guy? (What a sentence)
https://news.ycombinator.com/item?id=44719222
Could turn this into a 4 color display at the cost of drawing speed?
In addition to the user-controlled modes I also have ambient modes. My favorite is a clock that struggles to draw the current time because it takes too long
Basically you want to avoid keyframes on this thing, they'll kill you
https://trixter.oldskool.org/2014/06/19/8088-domination-post...
https://trixter.oldskool.org/2014/06/20/8088-domination-post...
Unfortunately I can't find the video. Will edit if I do (or anybody else finds it first).
https://www.smoothware.com/danny/woodenmirror.html
It had cubes in different colors so from further away it would look like an image.
I need to go find some corgi art to upload next!
How is it volume wise while it's working? Manageable or painful?