AncientJames

I built another row, and made some improvements to the sequencing system. It's now big enough to run a cycle of a glider:

I just built a cell from that model, and I discovered a few errors. Most importantly, it has two of the angled connector #3, where it should be using #5. I'll upload a fixed version, but look out for that if you do try building from the original model.

I've uploaded a model of the cell mechanism to bricksafe here. I used stud.io this time, but I can export it as something else if that's not generally convenient. The chassis and control unit will take a while to model, but will eventually appear in the same place. The cell is a pretty easy build - apart from making sure the moving parts move freely, there's no finessing or calibration needed. Just snap it together and it works. I couldn't get the rubber bands right in the model. It should be obvious where they attach. Knock the red lever to make it count. Push the orange liftarms up to make it flip. I haven't actually built one from this model, so consider it untested. Please let me know if you try building one and it doesn't work.

Oh yes, I was really excited when I saw your cellular automaton! My device does have a restriction on its rules that any given neighbour count can only flip in one direction. You can't, for example, have a rule where 3 neighbours will cause a dead cell to be born and cause a live cell to die. I'd like to try different rules, but Life has always been the one I come back to. You can implement the von Neumann neighbourhood by replacing the probe at the back with a shorter axle. An interesting possibility, since each cell carries its own copy of the rules, is to have different rules in different places. Using lower neighbour counts along the edges might help counteract the small size of the matrix.

I only finished this iteration of it at the weekend, so I don't know about long term reliability. It hasn't jammed or miscalculated yet. With a 3x3 matrix there isn't really any long sequence - I cranked the handle on a blinker until I got bored. There's a lot of building to do to get it up to the next grid size. Bonus build timelapse: http://www.youtube.com/watch?v=LtFyHihO5Cg

Vertically it would grind to a halt pretty soon, but horizontally, you could put a motor on each column and stack them indefinitely.

There's a fair bit going on here, and I'm still making the LDD files for it. The principle is pretty straightforward. In order to implement Life, you need a matrix of cells. At each step, each cell needs to count the number of live neighbours, and then change its own state based on that count. 3 live neighbours will cause a dead cell to come to life. 2 or 3 live neighbours will allow a live cell to stay alive. Any other count will result in the cell dying or remaining dead. Each cell is identical. At the front is the display, which can show alive (orange) or dead (black). At the back is a turntable which is used to poll its neighbours. At the heart of each cell is this setup: As the turntable revolves, each live neighbour it encounters knocks a lever which pulls on the axle on the right. This moves the blue linkage, which pushes the grey rule block up by one tooth. After a full revolution, the red pieces on the left are pushed in, and depending on whether they hit a tile or a gap in the grey rule block, push a rod on the left or the right of the mechanism. This sets the state to alive or dead. The block then drops down back to its starting position, and the cycle starts again. It's all modular, and given enough Lego you could make an arbitrarily large matrix. You can also swap out the rule block if you want to run a different cellular automaton.

Here's a device I've built which implements Conway's Game of Life:

I've just discovered bricksafe, so I've uploaded a little web app for programming the cards: http://www.bricksafe.com/files/AncientJames/flipdot/card.html

Awesome! Did you do it by hand, or is there a tool that automatically flips? Either way, thank you. The three blue 1x1 plates should be a single 1x3 plate, but LDD considers that to be illegal. The floating piece is something I've gone back and forth over - it goes on the steering arm at the bottom, replacing the 2L axle with a bar. This provides a little bit more play in the connecting rod to the press mechanism, which affects how smoothly it all runs. My current build doesn't use it, and I should have removed it from the file.

I've shared the LDD file for this display here: http://1drv.ms/1bSM59J This first version doesn't show the full construction. The missing pieces are all just mirror images of the other side, so all the information you'd need to build one is still there. I'm not sure whether it's more work to manually fill in the other side, or to write a tool to do it automatically. Some parts aren't currently available in LDD, and I've had to make substitutions. Where I've done this, I've coloured the substituted parts in pastel blue. The missing parts are:

And Kotaku: http://kotaku.com/mechanical-lego-display-is-another-level-of-awesomeness-1699666287

I just used that 16L link in my latest MOC! I got 8 of them in 1999 with the Y-Wing, and I hadn't used them for 15 years. It was a joyous moment when I found I needed a link of (almost) exactly that length.

The old scrolling version would probably be less of a headache at a show - you just turn it on and leave it going. The new one, you spend most of your time restacking the hopper. I'll have a go at attaching the LDD file for it. (edit: Looks like that didn't work.) There are some changes that would make it neater and more robust (I basically abandoned this version when I had the idea for the new one), but the big advantage is that you can make it as wide as you like.

You should totally build one! I'd love to see how well it works connecting two together.