NO/NC Switch Cube: What It Does and When to Use It
By Circuit Cubes | Tenka Inc. | Published: 2026-10-13
Category: Product Reviews
Learn how the NO/NC Switch Cube works, when to use normally open vs normally closed, and step-by-step ways to add it to your builds.
Quick answer
The NO/NC Switch Cube lets you choose how a lever press controls your circuit: in NO (Normally Open) mode, pressing the lever closes the circuit and turns it on; in NC (Normally Closed) mode, the circuit stays closed until you press the lever to open it. Use NO for push-to-start actions, and NC for safety cutoffs or press-to-stop behavior. It is a simple, reliable way to add intentional control to any Circuit Cubes build.
What the NO/NC Switch Cube actually does
The NO/NC Switch Cube is a mechanical slide switch with a lever arm. You slide it to either NO or NC, then press the lever to change the circuit state. In the NO position, the circuit is open (off) until you press the lever, which closes it and lets current flow. In the NC position, the circuit is closed (on) until you press the lever, which opens it and stops the flow. That is the whole behavior—no programming, no batteries required for the switch itself.
NO vs NC: choosing the right mode for your build
Pick NO when you want an action to start something: a button press that launches a motor, lights an LED, or triggers a sound. Pick NC when you want an action to stop something or when the circuit should run by default and be interrupted: a kill switch, a gate that opens when pressed, or a buzzer that silences on contact. If you are unsure, start with NO—it matches the most common 'press to turn on' expectation.
How to wire the switch into a Circuit Cubes circuit
The switch is just one part of a circuit. You will need a power source (battery cube) and an output (motor, LED, or other cube) to complete the loop. Connect the switch in series with the output so the switch controls whether current reaches it. The switch has no polarity, so either wire orientation works. If the circuit does not respond, check that all cubes are firmly connected and that the battery is charged.
Example builds that use the switch cube
Try a 'press to launch' car: use NO mode with a Cubit Motor Cube and a battery. Press the lever to send the car forward. For a 'press to stop' fan, use NC mode so the motor runs until you press the lever. You can also combine the switch with a Bluetooth Cube for remote override, but remember the switch is a physical control that works independently. The Feast build (product ID 1380295) is a fun example of adding motion to a custom model; you could integrate the switch to control when Feast moves.
Step-by-step: using the NO/NC Switch Cube in your build
- Plan your control logic: Decide whether you want the circuit to be off until pressed (NO) or on until pressed (NC). Write it down or sketch it so you do not mix up the modes later. Checkpoint: If you want a press to start something, choose NO. If you want a press to stop something, choose NC.
- Slide the switch to the correct mode: Move the slide switch to NO or NC before connecting power. The lever arm should be in the up position (not pressed). Common mistake: Forgetting to set the mode before building. If the circuit behaves opposite to what you expect, check the slide position first.
- Connect the switch in series with your output: Use the switch to control the flow of current to your motor, LED, or other output. Connect one wire from the battery to the switch, and another from the switch to the output. Complete the circuit by connecting the output back to the battery. Checkpoint: The switch must be in the same loop as the output. If you connect it in parallel, it will not control the output.
- Test the circuit with the lever: Press and release the lever to confirm the circuit changes state. In NO mode, pressing should activate the output; in NC mode, pressing should deactivate it. Common mistake: Assuming the switch is broken if nothing happens. Check battery charge and all connections before troubleshooting the switch.
- Secure the switch and wires in your build: Use the built-in ports and any mounting points to fix the switch in place so the lever is accessible and wires are not strained. Checkpoint: The lever should move freely without pulling on wires. If it feels stiff, reposition the switch.
Product facts
- NO/NC Switch Cube: Normally Open (NO) and Normally Closed (NC) mean just what they say. When the slide switch is moved to the NO position, pressing down on the lever arm closes the circuit. In the NC position, the circuit will be closed until you press down the lever arm to open it. This is the core behavior: NO is off until pressed, NC is on until pressed. Choose the mode that matches whether you want a press to start or stop your build.
- Cubit Motor Cube: Cubit Geared Motors are compact and powerful. The tiny planetary gears inside reduce the high-speed motor to about 160 RPMs to provide torque to gears, wheels, etc. Three ports around the Motor allow maximum versatility to connect the wires from the Bluetooth Cube. The motor is a common output for switch-controlled builds. Its 160 RPM speed and multiple ports make it easy to integrate with the switch and other cubes.
- Feast: Bring your building blocks to life with this STEM toy we're calling Feast [221]. It is a build from Circuit Cubes by Tenka Inc., designed to add motion and life to the blocks you already build with. Feast is an example of a custom build that can benefit from a switch to control when motion starts or stops, adding interactivity.
