Build BitFlip: a Modular Take on Physical Computing

BitFlip is a modular physical computing system that turns invisible digital logic into something you can touch, build, and watch in motion.

Instead of screens and code, BitFlip uses mechanical gates, binary inputs, pathways, and marbles to demonstrate how computation works in real time.

This project combines product design, education, gameplay, and open-source experimentation into one expandable tabletop system.

BitFlip by Sujal Khera is licensed under Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0).

You may build, remix, and share with credit. Commercial use requires permission.

Acrylic + Cutting

1. Cast acrylic sheets
2. Option A: 300 × 300 mm sheets in blue, orange, red, and yellow
3. Option B: One large 600 × 600 mm clear acrylic sheet
4. Laser cutter or access to a laser cutting service

3D Printed Components

1. Access to a 3D printer or local 3D printing service
2. If using colored acrylic sheets: print parts in white filament
3. If using clear acrylic: use blue, red, orange, and white filament

Color System

Use this if building with clear acrylic and limited filament color options.

1. Spray paint in:
2. Blue
3. Yellow
4. Orange
5. Red

Assembly

1. Super glue (only if required)

Final Requirement

1. Patience, curiosity, and the wildly unnecessary commitment to building a physical computer for pleasure.

BitFlip turns binary logic into motion.

Set the inputs, place the gates, release the marble, and observe the final output. Each path physically represents a computational decision.

Instead of hidden code, logic becomes visible, tactile, and playable.

Scan the QR to go to the BitFlip interactive and understand everything

BitFlip is built from modular parts:

1. The Board
2. Team Gate(AND gate)
3. Any Gate(OR gate)
4. Unpredictable Gate
5. Trap Gate(ERROR)
6. 3bit Binary(1/0) Counter

Each part can be rearranged to create new logic systems, puzzles, or game modes.

Start by preparing all parts before beginning final assembly.

Use 1.8 mm acrylic sheet thickness (measured after removing the protective sticker) for best fit and smooth operation. Files for both clear acrylic and pre-colored acrylic sheets are included.

Laser Cutting Instructions

For all laser cut files:

1. Red lines = full through cut
2. Blue lines = surface etching / engraving

Check scaling is set to 100% before cutting. Even tiny errors become dramatic when parts refuse to fit, a timeless human tradition.

3D Printed Parts

Once laser cutting is complete, prepare all 3D printed components.

1. If printing in white or single-color filament, spray paint the parts to match the reference image.
2. If using multi-color filament or colored acrylic builds, painting is not required.

Make sure all parts are cleaned and supports removed before moving to assembly.

Start by laser cutting the acrylic sheets using the provided files.

1. Take B1, align it lengthwise vertically.
2. Then, take B2 and B3 and insert them into the slots on either side of B1.
3. Pick up the legs labelled as B4 and B5, insert the legs into the slots made for the legs on B1, to give the board a uniform incline.

Voila, you have the board ready

Building the Bits

Assemble the Bits modules using the labeled laser-cut acrylic parts shown in the file. These modules create the main logic pathways used during gameplay.

Parts Used

1. G1, G2, G3, G4 = Bit acrylic base plates
2. G = Side wall panels for each Bit module
3. Matching 3D printed internal guide pieces for each Bit

Assembly Order

1. Select the required Bit base plate (G1, G2, G3, or G4) and place it flat on the table.
2. Insert the matching 3D printed guide component from the bottom into the designated slot on the base plate. Make sure it is fully seated and correctly oriented.
3. Insert the acrylic G side wall panels into the surrounding slots on the base.
4. Press all tabs gently into place until the module is square and stable.
5. Repeat this process for each remaining Bit module.

Important Notes

1. Dry fit all parts before gluing. Optimism is not an assembly method.
2. Red is the first step and yellow is the second step
3. Keep side walls straight and parallel for reliable marble movement.
4. If any slot is tight, lightly sand the edge rather than forcing it.
5. Use a small amount of super glue only after confirming alignment.

Final Check

Test each finished Bit by rolling a marble through the channel.

The marble should move smoothly through the path without catching, stopping, or launching itself into rebellion.

Assemble the Binary Coder module using the labeled acrylic parts. This section acts as the lower interaction zone for creating and reading binary outputs.

Parts Used

1. C1 = Binary base panel
2. C2, C3 = Side wall panels
3. C4 = Bottom front panel

Assembly Order

1. Place C1 flat on the table with all slots facing upward.
2. Insert C2 and C3 into the side slots of C1 to form the left and right walls.
3. Insert C4 into the front bottom slot to close the lower edge of the module.
4. Press all tabs fully into place until the structure is square and stable.

Important Notes

1. Dry fit all panels before gluing. Confidence has ruined many assemblies.
2. Keep side walls vertical for smooth alignment of internal parts.
3. If any tab is tight, lightly sand the edge instead of forcing it.

Final Result

You should now have a rigid Binary Coder tray ready for installing the internal switches and gameplay components.

Installing the Switches

Prepare all switch components before placing them into the board.

Switch Types Required

1. 1 × Binary Switch
2. 14 × General Switches
3. 2 × Randomiser Switches

Installation Order

1. Sort all switches by type and keep them separated before assembly.
2. Locate the etched markings on the 3D printed parts and board modules. These markings indicate the correct switch position.
3. Match each switch type to its corresponding etched location.
4. Press each switch gently into place until it seats securely and moves freely.
5. Repeat until all switch positions are filled.

Important Notes

1. Do not force any switch into the wrong slot. Parts tend to object dramatically.
2. Check that every switch pivots or moves smoothly after installation.
3. If fitment is tight, clean the slot edges or lightly sand the contact area.

Final Check

Once installed, test each switch by moving it through its full range. Every switch should reset cleanly and remain stable in position.

Visit the BitFlip interactive website and create a logic setup using the digital simulator.

Choose your gates, arrange their positions, and test different switch combinations before building the same layout on the physical board.

Once you have a working path:

1. Recreate the same gate arrangement on the BitFlip board.
2. Match the switch positions to the website setup.
3. Place a marble at the starting point.
4. Release it and compare the physical result with the digital simulation.

This lets you prototype ideas digitally, then test them in the real world where gravity becomes your processor.

Try This Starter Setup

1. Top Row: Team Gate
2. Middle Row: Randomiser Gate
3. Bottom Row: Achieve Any Output On The Binary Coder And Calculate on Website

Test multiple switch states and observe how each change affects the final binary output.

Final Result

The website becomes your planning tool, and the board becomes the live hardware version of the same logic system.

For each mission, use the 2 specified gates only, place them in Gate 1 and Gate 2, then try to reach the required Final Binary Output (0-7).

Available gates:

1. Team Gate
2. Any Gate
3. Trap Gate
4. Randomiser Gate

Two gates, one target, and fresh opportunities to misjudge cause and effect.

Challenge 1: Traffic Override

1. Use: Team Gate + Any Gate
2. Target Output: 3

The Team Gate represents traffic systems working together, while the Any Gate allows one open lane to keep vehicles moving.

Challenge 2: Secure Entry

1. Use: Any Gate + Any Gate
2. Target Output: 1

Either sensor can unlock the system, so two Any Gates model flexible access control.

Challenge 3: Factory Shutdown

1. Use: Team Gate + Trap Gate
2. Target Output: 6

The Team Gate requires two fault conditions together, while the Trap Gate represents an emergency stop or dangerous failure zone.

Challenge 4: Storm Route

1. Use: Randomiser Gate + Any Gate
2. Target Output: 2

Weather and road conditions are uncertain, so the Randomiser Gate adds unpredictability while the Any Gate keeps backup options open.

Challenge 5: Power Recovery

1. Use: Team Gate + Team Gate
2. Target Output: 7

Restoring full power needs multiple systems working in coordination, making two Team Gates the ideal choice.

Challenge 6: False Shortcut

1. Use: Trap Gate + Any Gate
2. Target Output: 5

One path looks easier but fails, so the Trap Gate punishes bad choices while the Any Gate preserves an alternate route.

Bonus Challenges

1. Reach Output 4 using Team Gate + Randomiser Gate
2. Reach Output 0 using Trap Gate + Trap Gate
3. Reach the same output with two different gate pairs
4. Let a friend choose the gates, then solve it blind

BitFlip turns decision-making into something visible, physical, and pleasantly unforgiving.

The included files can be modified to create new boards, new gates, new rules, and larger systems.

You can also print the Make Your Own template and sketch your own logic ideas using walls, paths, and switches. Keep the marble diameter in mind while designing, so every route remains playable instead of becoming a monument to optimism.

Share your custom layouts and remixes. The best concepts can be converted into proper CAD files for fabrication, allowing your design to become a real BitFlip expansion.