How to Make a Split Flap Display: Oat Foundry’s Process

Split Flap displays are intricate mechanical systems where motion, sound, and precision engineering come together to create a uniquely analog experience. Building these displays requires careful planning, mechanical fabrication, electronics, software, and extensive hands-on craftsmanship. Each module contains a carousel of characters that must rotate at exactly the right moment, in perfect synchronization with dozens, hundreds, or even thousands of other modules.

Building a Split Flap at Oat Foundry

At Oat Foundry, building a branded Split Flap display is an engineered and intricate process. As every sign or kinetic wall installation is made to order and assembled by hand in our Philadelphia shop, we follow the same refined steps to ensure that every display we construct is of the highest quality. Here’s an overview of our bespoke process from start to finish. 

Watch our process here, and see how just one set of flaps gets updated with a custom logo here. 

The Drawing Board 

At Oat Foundry, building cool stuff starts with planning cool stuff. 

Every Split Flap display we create is bespoke—designed for a specific space, brand, and experience. Before production begins, we work through the design details that will shape the project: display size, colors, messaging requirements, mounting approach, and the technical needs of the installation environment.

Even our smallest boards contain thousands of individual components. Larger installations can exceed 50,000 parts, all working together in coordinated motion.

Because each board is custom-built, careful planning ensures the display performs exactly as intended once it arrives on site. Once the design is finalized, our production team begins building the display from the ground up.

The Hardware: Metal Cabinet and Framework

Every lover of puzzles knows you start with the frame. If you’re wondering how to make a Split Flap display, you’d be wise to take a page from their book. Every Split Flap display begins with its cabinet—the structural backbone that supports the entire system. The cabinet starts as bare sheets of cold-rolled steel fabricated by our partners at General Metal Company, located just up the road from our Philadelphia shop. Their team laser-cuts and bends sheet metal into the precise shapes needed for our cabinet panels. Before assembly, the pieces of the metal framework are powder-coated in either our classic black, a modern white finish, or a custom color selected by the client, such as Kit Kat red or Julith Coffee cobalt blue.

The Kit Kat Chocolatory retail signage was custom-matched to red, the brand’s signature color. Pictured: 5 Row x 32 Column display.

Julith Coffee selected a custom color, Cobalt blue, for their Split Flap display as their interactive cafe menu signage.  Pictured: 7 Row x 32 Column display.

Once the coated panels arrive at our shop, our technicians rivet together a series of uniquely designed components to create a rigid frame capable of supporting rows of modules and electronics. The panels themselves are designed to be modular, built in sets of eight columns. This modular approach allows Split Flap displays to expand to virtually any length while maintaining a consistent structural pattern.

As a result, we can create displays ranging from compact installations to massive architectural features—such as our 7-row by 168-column (40-foot) display at the Kendall Center. This extensible sheet metal system allows each board to be precisely tailored to the space it will inhabit while maintaining the strength and precision required for long-term operation.

The Tech That Makes It Tick

With the cabinet complete, the electronics that power the Split Flap display are installed. Inside the cabinet, technicians carefully route wiring and install circuit boards to coordinate communication among modules. These boards house hundreds of electronic components and constantly exchange information with the display’s main controller, located in the header section above the modules.

This network forms the display’s nervous system, allowing every module to be addressed individually and precisely coordinated. It’s what enables complex animations, seamless transitions, and the synchronized motion that defines the Split Flap experience.

To make the user experience seamless and natural, we also developed Portal, proprietary software that comes free with every Split Flap display. Portal is a content management system that allows users to control the messaging, timing, and animation styles of their Split Flap display with precision. It’s based on popular, easy-to-use interfaces, so users without technical expertise can navigate it with ease from either a phone or a computer. 

Printing the Flaps

With the cabinet and electronics prepared, attention turns to the most recognizable element of the display: the flaps themselves. Each module contains 50 individual flaps, printed with characters, symbols, or custom graphics. We work with two trusted regional partners to produce them. After printing and cutting, our technicians then punch them out by hand and install them one by one into a rotating carousel (as described in our nifty Analog Dictionary). 

Any leftover material from the process is recycled locally.

Modules: The Stars of the Show 

When thinking about how to make a Split Flap display, the flapping modules themselves are always the first image that pops to mind. But without all the behind-the-scenes work discussed up until this point, they’d have nowhere to live. Here’s where modules come into play. 

The modules contain the iconic flaps and the analog system that rotates them into place. Like the cabinet panels, modules begin as flat pieces of metal that our partners at General Metal Company cut and bend. After precision bending and powder coating, they arrive at our shop ready to be assembled into working units.

Each module receives a custom printed circuit board and a carefully selected stepper motor. The motor drives the carousel that holds the flaps, rotating through them with precise control.

Once assembled, the module becomes a fully functioning analog device capable of flipping through characters with the iconic motion and sound associated with Split Flap displays.

Sign Assembly: Bringing It All Together

With modules complete, the display finally begins to take shape.

Technicians install each module into its designated position inside the cabinet. Modules are hung and connected to the cabinet’s wiring network, receiving both power and data.

Installation proceeds row by row, starting from the bottom and working upward. Once all modules are in place, the header panel is attached, concealing the electronics and completing the display’s front face.

At this stage, the board is fully assembled and ready for testing.

Quality Assurance: Installation and Testing

Before shipping, each module is rigorously tested to ensure that the mechanical and electrical components function properly and that Portal integrates with the system. We don’t package our displays until each module has undergone 50,000 rotations under supervision in our shop. Over several days, our team monitors each module to ensure smooth motion, accurate positioning, and flawless communication with the system controller.

Once testing is complete, each module is calibrated so that all flaps across the display—whether there are tens, hundreds, or thousands of them—land in perfect synchronization. Only modules that complete testing without a single issue are approved to move forward. By completing 100% functionality inspection and testing before the displays leave the shop, clients can ensure boards can be easily installed and integrated. 

Crating and Packaging

The modules and cabinet are then carefully packaged and shipped out to their new home. Our partners at Arrow Crating and Packaging, located just across the Delaware River, build foam-lined crates designed specifically for the display’s size and configuration.

Smaller displays are typically shipped with modules already installed. Larger boards are shipped with the cabinet structure and the modules separated. In those cases, modules are labeled, bagged, and boxed to make on-site installation straightforward.

Worldwide Shipping

Once crated, the display begins its journey.

Our boards travel by truck, plane, and shipping container, often crossing multiple countries and continents before arriving at their final destination. Throughout the process, we coordinate closely with shipping partners and installation teams to track the display and ensure safe delivery.

Over the years, Split Flap displays from our Philadelphia shop have traveled across the United States and around the globe—to Central America, the UK, Switzerland, Hungary, Azerbaijan, Hong Kong, Australia, and beyond.

Installation: The Final Step

Installation day is always exciting. It means the display is about to come to life.

The cabinet is mounted to the wall or structure using the included hardware and carefully leveled. If modules were shipped separately, they are installed in their labeled positions from the bottom row upward.

Once power and data are connected, the display springs to life — flipping characters into place with the unmistakable rhythm of analog motion.

Many of our installations are completed by teams already working on the project site, including general contractors, electricians, and maintenance staff. Our team is always available to answer questions, assist remotely, or provide on-site support when needed.

Split Flap Display DIY: For the Hardcore Hobbyists 

Building a DIY Split Flap display is a fantastic challenge for hobbyists with experience in mechanical and electrical engineering, coding, and arts and crafts.

So much, in fact, popular engineering YouTubers Engineezy, Dave Madison, and Scott Bezek have taken on DIY split-flap display projects and documented their experiences. 

Their videos and content demonstrate what we know to be true: analog technology is both much harder – and much cooler – than its digital counterparts. Watching either video gives a clear sense of how intricate even a single Split Flap display module is, and of the engineering know-how embedded in every component of a Split Flap display board. So if you’re an expert mechanical and electric engineer with coding know-how and the patience to hand-letter dozens, if not hundreds (or thousands) of flaps, a Split Flap display DIY project might be the right fit for you.