In plain English
This page skips the engineering. The technical summary has the numbers.
What this is
A split flap display is the mechanical board that used to hang in train stations and airports, where each letter sits on a stack of little cards that flip over until the right one shows. They clatter, they move, and they were replaced by screens decades ago because screens are cheaper.
flip forward makes them buildable again. The design, the instructions and the software are published for free, so you print most of a display yourself and buy the few parts you can't print. It's run by one person in Germany, not a company.
How it works, briefly
A display is built from identical boxes called modules, one per character. Inside each is a drum carrying 43 thin plastic flaps, turned by a small motor. A magnet and a sensor tell the module where the drum is, so it can turn to any letter on demand rather than cycling in a fixed loop the way an old flip clock does.
Modules clip straight together, so a row has no wiring to build, and only the first module in a row joins your WiFi. It passes instructions along to the rest.
What it costs
Two routes, and the difference matters.
Build it yourself. Every price on this site, including everything the display planner works out, is the cost of the parts only. A module's parts come to roughly €15–90 depending on whether you print the case and flaps or buy them ready-made, and whether you use the cheap motor or the good one. Your own time isn't in that figure, and the first module takes an hour or two to assemble.
Have it built. Assembled modules and finished displays can be ordered instead. They cost more than the parts, for the obvious reason, and they're quoted per project because flaps, case, power supply, mounting and shipping all depend on what you're building. For scale: for a commissioned installation, budget meaningfully above the parts figure rather than treating it as the price.
Either way it undercuts the commercial alternatives, which start around €1,000 for a small finished unit and climb steeply for anything custom.
What you need
For a self-build: a 3D printer, a stepper motor, two small circuit boards, a magnet, a handful of M3 screws per module, and a 12 V power supply for the display. No soldering, no programming, no laser cutter. Flaps and cases can be printed at home or bought.
For a commissioned build: a wall, a deadline and an idea of the size. Send those to hello@flipforward.de and you'll get a quote back.
Before committing either way, play.flipforward.de will show you a working display on screen, at your size and with your content, without any hardware.
Asking an AI about the project
Everything on this site is also published as one plain text file, so you can hand ChatGPT, Claude or a local model the whole documentation and ask questions in your own words.
If your assistant can browse the web:
Read https://www.flipforward.de/llms-full.txt in full, then answer my
questions about the flip forward split flap display system using only
what that document says. If it doesn't cover something, say so rather
than guessing.
My first question: <your question>
If it can't browse, or you're running a model locally, download llms-full.txt and attach it to the conversation instead. It's about 95 KB of plain text, well within what current models handle. There's also a shorter llms.txt listing every page, which some tools prefer.
Ask it what a 3 × 12 display would cost in parts, whether a wall recess needs ventilation, or what a print shop needs for custom flaps. One caveat: a model will invent a plausible part number or dimension without hesitating. Check anything you're about to spend money on against the page it came from, or ask on Discord.