Show HN: I spent 6 years building a ridiculous wooden pixel display (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.

https://kilopx.com/

Comments (44)

re · 11m ago

Really cool! I just watched it finish "cat saying 'hi'". It doesn't look like any new posts have shown up on @kilopx.com on Bluesky for the last 9 days though.

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).

fentonc · 45m ago

Awesome project! I built a somewhat similar 30-pixel display: https://www.chrisfenton.com/the-pixelweaver/

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.

benholmen · 30m ago

This is incredible! I can appreciate how much work it took to make this happen. Well done!

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!

derefr · 37m ago

Speaking of "alternatives to e-ink for a zero-power-use-when-not-updating dot-matrix display"...

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 class, that can be "refreshed" by printing a new full-width image to the thermal printer?

(I feel like this would be especially neat because the resulting display could be really long. Not very wide, though—I don't think you can get thermal paper rolls much wider than standard receipt-printer size. Correct me if I'm wrong!)

cgriswald · 34m ago

Allow me to correct you: Some fax machines use thermal paper so your display can be at least 8.5".

tristor · 15m ago

Ooh, I like this idea. You could also use the box structure to stretch the display so it has 4 sides if you build the mechanism correctly, which means as you refresh the image on the "primary" display it moves the other images to the secondary, tertiary, and quaternary displays before it gets taken up. You can use tensioned rollers at each corner hidden by the frame if you plan for a gap for "bezel".

xpe · 49m ago

Another idea: have the cubes point an edge straight forward (instead of a face). Then if each cube has two adjacent dark sides and two adjacent light sides, one could setup two ‘simultaneous’ images: one viewed from the left at 45° and another viewed from the right. (Each pixel would have four possibilities.)

boothby · 20m ago

Similarly, the camera could stay face-on and double the pixel count with largely the same hardware.

saltcured · 15m ago

I keep trying to imagine "faster" variations.

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.

rented_mule · 10m ago

Your idea is not too far from marble pixel art machines... https://youtu.be/w1ks0Vy98KI

jstanley · 13m ago

Hah, cool, I had an idea for a similar project (although I'm not crazy enough to make 1000 pixels, or a robot to turn them for me). But I got as far as making a JavaScript simulation and realised I couldn't be bothered manually turning the beads https://incoherency.co.uk/beadboard/

aarondf · 1h ago

This has to be the the most expensive cost per pixel display I've ever seen. And I've never loved a display more. This is absurd in the best possible way

Rexxar · 24m ago

And absolutely no energy consumption when you don't change the image.

benholmen · 1h ago

I don't think I want to think of the actual cost per pixel - especially the cost of my time! I have deliberately avoided accounting the final cost

zahlman · 1h ago

For what it's worth, dollar stores typically sell wooden cubes for arts & crafts purposes (board game designers also like them for prototyping) in bags that work out to a few cents per piece. I guess they're quite a bit smaller than what you ended up using, though. And of course that doesn't account for the frame or the control mechanism. (And now you have me trying to think of more robust ways to turn the pixels...)

xpe · 54m ago

You could order the presentation of a set of images by some distance metric :)

- naively: Levenshtein

- better: real world edit time based on a model of the display : probably dominated by XY travel distance

munificent · 15m ago

I was wondering about the algorithm to drive the plotter and update pixels, which ties into this.

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".

benholmen · 49m ago

Oh I kinda love the idea of drawing the next one based on the pixel diff! Would be fun to game that queue.

skrebbel · 13m ago

you could have it render a movie

cinntaile · 1h ago

There was a fish project on here a few days ago that also had to deal with uh... adverserial images and it was (mostly?) solved by training a neural net to detect those.

benholmen · 53m ago

TTFP will surely be < 1 day

boredpudding · 46m ago

This used to exist! I remember a video about this large analog billboard in Amsterdam (?).

Unfortunately I can't find the video. Will edit if I do (or anybody else finds it first).

smokel · 37m ago

Perhaps you are thinking of Daniel Rozin's "Wooden Mirror" (1999)?

https://www.smoothware.com/danny/woodenmirror.html

boredpudding · 17m ago

That's a very good one, but in my case it was a huge billboard that was advertising movies and stuff.

It had cubes in different colors so from further away it would look like an image.

benholmen · 29m ago

Rozin was a direct influence on me! Seeing his stuff ~10 years ago got me thinking about unorthodox displays.

mosdl · 1h ago

Really cool and it would totally work for a restaurant/coffee shop.

benholmen · 1h ago

I think I might put this in my friend's coffee shop but I'll restrict access to people in the coffee shop. Not going to let the internet get a hold of that.

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

Mabusto · 57m ago

You gotta do the classic bouncing logo from The Office.

benholmen · 45m ago

Genius. I'll do this when I install it in my Zoom background and take it off the internet

xnx · 1h ago

Wow. Impressive. I would never have guessed you'd use a Vanna White / Wheel of Fortune turning method.

benholmen · 53m ago

That it, the method will forever be called the Vanna White Method

mjwhansen · 17m ago

Ben, can I get a vowel, please?

joetannenbaum · 1h ago

Incredible write-up and a hugely ambitious project. Thanks for sharing!

eclipticplane · 1h ago

Amazing.

Could turn this into a 4 color display at the cost of drawing speed?

benholmen · 54m ago

Yes! I have an RGB sensor that could handle that, but it's more bulky than the simple IR on/off sensor I went with. Could be four colors, or four shades of a color.

cgriswald · 39m ago

This is great, but you can get even more impractical: build a framebuffer!

mjwhansen · 19m ago

Such a cool project, Ben!

joshmanders · 38m ago

This is awesome, Ben!

ashleyhindle · 49m ago

This is so great

How is it volume wise while it's working? Manageable or painful?

benholmen · 28m ago

Pretty quiet! I spent some time figuring out how to make sure the stepper motors don't whine (the answer is microstepping and decent motor controllers). The pixel turning is very quiet unless it misses slightly, then it makes a clunk.

explodingwaffle · 1h ago

This is awesome! Just so you know, you are legally obligated to do Bad Apple when interest dies down.

alnwlsn · 1h ago

By my estimation, it would only take 1/3 of a year to render

benholmen · 1h ago

y'know, I've been excited / feared that Bad Apple would show up. The good news is a lot of frames would probably just be a few pixels to change from the previous frame, so some might draw really quickly.

Basically you want to avoid keyframes on this thing, they'll kill you

drivers99 · 25m ago

Some of the ports of Bad Apple have had to deal with this and they narrowed it down to the few changes needed for each frame. When there were too many pixels to change all at once, they would make fewer changes in exchange for a loss of quality.

https://trixter.oldskool.org/2014/06/19/8088-domination-post...

https://trixter.oldskool.org/2014/06/20/8088-domination-post...