Small & Sensitive Bite Switch

This project is a custom-made bite switch designed as a low-profile, high-sensitivity assistive device for users who require hands-free input. By leveraging a compact momentary tactile switch housed within a flexible, 3D-printed lever assembly, the device allows for reliable activation through minimal jaw movement or pressure. This makes it an ideal solution for individuals with significant mobility impairments who need to control devices via oral or facial movements.

The bite switch is engineered for seamless integration with assistive technology, connecting to the Xbox Adaptive Controller or similar interfaces via a standard 3.5 mm jack. This allows the switch to be mapped to any specific button or trigger command, providing the user with a vital link to gaming, communication, or environmental control.

Key features of this design include:

1. Ergonomic Low-Profile Geometry: The tapered, wedge-shaped housing is designed to fit comfortably within the mouth or against the cheek, minimizing fatigue during extended use.
2. Mechanical Leverage: The integrated top plate acts as a lever, amplifying the user's force and providing a larger target area to ensure the internal button is triggered even with slight or off-center pressure.
3. Durable and Hygienic Potential: Utilizing 3D-printed materials allows for easy replacement and customization, while the simple internal wiring is protected by heat-shrink tubing to ensure longevity and safety.
4. Cost-Effective Accessibility: By using readily available electronic components and a streamlined 3D-printed frame, this switch provides a professional-grade accessibility tool at a fraction of the cost of commercial alternatives, empowering makers and users alike.

Electronics

1. 1 Button Switch, ~1 cm × 1 cm, ≤1.5 cm² surface
2. Wires to connect the button to the 3.5 mm jack (type, length, and thickness can vary depending on your button, jack, and soldering preference)
3. 1 3.5 mm Jack compatible with the Xbox Adaptive Controller (male or female, panel-mount optional)
4. Heatshrink Tubing (Optional to make button extra sensitive, and to make wiring safe)

3D Printed Parts

1. 1 Main body printed in PLA

Adhesives

1. Hot glue To the secure button in place)

Tools

1. Soldering Iron and Solder
2. Wire Cutters/Strippers (if needed to adjust wires)
3. Tweezers or Small Pliers (optional, for positioning wires/components or removing supports)

Extras

1. Flux (optional, for better soldering)
2. Plastic Bag (to cover the button housing)

3D Print the Parts

Start by printing the internal frame for your bite switch. This design utilizes a minimalist 3D-printed skeleton to provide structure, while a food-grade plastic sleeve acts as the final outer housing to ensure a hygienic, moisture-resistant barrier for the electronics.

Download and open the 3D files in your slicer (STL format). You will see the core components:

1. Tactile Lever Frame: The primary "V" shaped structure that holds the switch in place and provides the spring-back tension for activation.
2. Base Plate: The bottom support that secures the wiring and provides a solid foundation for the switch.

Recommended print settings:

1. Material: PLA. Since the part will be encased in a plastic bag during use, standard filaments are perfectly suitable for the internal structure.
2. Layer height: 0.2 mm.
3. Infill: 20% (Grid or Gyroid infill is recommended for consistent spring tension in the lever).
4. Supports: Not required.

Before moving on:

1. Smooth the Surfaces: Ensure there are no sharp points or "zits" on the print that could puncture the plastic bag housing.
2. Prep the Housing: Select a small, durable, food-safe plastic bag (such as a heat-sealable sleeve or a small poly bag) that will fit snugly over the assembly once the wiring is complete.

Wiring the Switch

Prepare the components:

1. 3.5 mm Mono Cable: Use a cable with a standard jack on one end and exposed wires on the other. If you are recycling an existing cable, strip the outer insulation to reveal the two internal wires (typically red and black, or white and black).
2. Tactile Button: Use a 2-pin or 4-pin momentary tactile switch. If using a 4-pin switch, ensure you are soldering to the pins that form a normally open circuit.

Wiring Steps:

1. Strip and Trim: Strip about 5 mm of insulation from the ends of the cable wires. Apply a small amount of solder to the tips of the wires and the pins of the button to make the final connection easier.
2. Solder the Button: Solder one wire to each side of the tactile switch. Since this is a simple momentary switch, polarity does not matter—one wire to one pin, and the other wire to the opposite pin.
3. Insulate: To prevent short circuits and protect the joints from moisture, slide a piece of heat-shrink tubing over each connection or use a small amount of electrical tape, but do not shrink it yet. If you shrink it now, the button will not fit correctly.
4. Extra Info: Heatshrink tubing is especially important for this build, as the wiring will be tucked through the 3D-printed frame before being sealed in the plastic housing.

Seating The Switch

Seat and Secure the Switch: Place the tactile button into the tallest point within the 3D-printed base. Once positioned, apply a small amount of hot glue around the base of the switch to secure it firmly in place. This prevents the button from shifting during use and ensures consistent activation.

Route the Wires: Carefully route the wires through the exit hole. Use another drop of hot glue at the exit point to act as a strain relief, protecting the solder joints from being pulled. Ensure no wires are pinched by the mechanism.

Final Wiring Steps:

1. Strip and Trim: Strip about 5 mm of insulation from the ends of the wires attaching to the button and to the jack. Apply a small amount of solder to the tips of the wires and the pins of the button to make the final connection easier.
2. Insulate: To prevent short circuits and protect the joints from moisture, slide the piece of heat-shrink tubing that you put on the wire earlier to cover each connection or alternatively use a small amount of electrical tape if you forgot to slide on the piece of heatshrink tubing.

Final Testing & Setup:

1. Seal The Switch: Grab a plastic bag and wrap it around the controller tightly. To ensure a snug seal, you can use twine or an elastic band.
2. Controller Sync: Plug the 3.5 mm jack into your Xbox Adaptive Controller.
3. Input Verification: Open the "Xbox Accessories" app on your console or PC to verify that the switch registers a signal every time it is pressed.
4. Comfort Check: Before use, inspect the Ziploc housing for any sharp edges or loose plastic. Ensure the device feels stable and the activation force is comfortable for the intended user.

Example Video: Click Here

Side Note: For hygiene purposes, it is recommended to replace the plastic bag housing regularly, especially after heavy use.