Circuit Cubes Parts Explained: Motors, Gears, Wires, and LEDs

Quick answer

Start with a Cube Combo if you need both power and motion, add a Gears Go Kit when you want gears, wheels, and axles in one box, and buy individual parts like the Cubit Motor Cube, RGB LED Cube, Gearbox - #6585, or Tire - 30.4 x 14 - #92402 only when you already know the exact piece you are replacing. Match the connector type and the mechanical fit before you buy, because not every part works with every build.

Circuit Cubes builds are simple on the surface: a battery, a motor, a light, and a few wires. The confusion starts when you need to replace one piece or add a new function. Is the motor the problem, or the gearbox? Do you need a new wire, or a different Cube?

This guide breaks the system into four part groups — motors, gears, wires, and LEDs — and gives you decision rules for buying replacements or spares. It uses only the catalog facts available for each product, so you can compare what is actually included before you spend.

Motors and power: what each Cube does

The Cubit Motor Cube is the motion source. Its catalog description says the tiny planetary gears inside reduce the high-speed motor to about 160 RPMs to provide torque to gears and wheels, and it has three ports around the motor for connecting wires from the Bluetooth Cube. If your build moves but stalls under load, the motor is usually working — the gearing or wheel size is the limiting factor.

The Cube Combo pairs a classic Battery Cube with a Geared Motor Cube. The Battery Cube delivers approximately 3.7–4.2 volts DC when switched on, and the Geared Motor Cube rotates at more than 1,000 RPM before its internal gears reduce speed. That difference matters: the Combo is the fastest way to get a powered, moving build, while a standalone Cubit Motor Cube is a replacement or expansion part.

• Buy the Cube Combo when you need power and motion together; buy the Cubit Motor Cube when you already have a battery and only need to replace or add a motor.
• If a build is slow but strong, you are seeing torque; if it is fast but weak, you are seeing speed. Change the gearing or wheel size before replacing the motor.

Gears, wheels, and the Gears Go Kit

Gears and wheels are where most fit problems appear. The Gears Go Kit is a multi-vehicle launch kit that includes a rechargeable Battery Cube, Motor Cube, RGB LED Cube, and 71 total parts such as bricks, wheels, gears, and axles. Because it bundles the core electronics with mechanical parts, it is the most efficient purchase when you are starting from nothing or replacing several categories at once.

For single replacements, the Gearbox - #6585 is a quantity-one gearbox part, and the Tire - 30.4 x 14 - #92402 is a quantity-one tire. Neither listing supplies a diameter or tooth count beyond what is written, so treat the part number and the stated size as your fit check. If you are unsure whether a gear or tire matches your current build, compare it to the part you are removing before ordering.

• Measure or note the old part before buying a replacement; the catalog lists part numbers and sizes, not full compatibility charts.
• When you need several gear sizes at once, the Gears Go Kit is usually cheaper than assembling the same parts individually.

Wires and connectors: the part that stops most builds

Circuit Cubes circuits depend on seamless connectivity between Cubes. The Cubit Motor Cube listing specifically mentions three ports around the motor to connect wires from the Bluetooth Cube, and it includes custom axles in 10mm and 14mm lengths. That tells you the motor is designed to accept multiple wire connections, which is useful when you want to route power around a crowded chassis.

The catalog does not list a separate wire or connector part with its own specifications, so do not assume a generic cable will fit. If a build will not run, check the connection points first: reseat each wire, confirm the battery is switched on, and test the motor directly. Only replace a wire or Cube after you have ruled out a loose connection.

• Test one Cube at a time to isolate whether the fault is the wire, the battery, or the motor.
• Keep spare axles and connectors from kits like the Gears Go Kit; they are the parts most often lost.

LED parts and adding light to a build

The RGB LED Cube contains three LEDs in one bulb — red, green, and blue — with small switches to turn each one on. You can mix the colors to get purple, teal, and yellow. The catalog is clear that the RGB LED Cube is just one part of a circuit: it needs a battery to power it and a motor to make a build move, so it is an add-on rather than a standalone toy.

That makes the RGB LED Cube a good second purchase. If you already own a battery and motor, adding the LED Cube changes how a build looks and behaves without changing its mechanics. If you are buying your first Circuit Cubes product, choose a kit that already includes the LED Cube so you are not buying the same function twice.

• Add the RGB LED Cube when you want visual feedback or a night-light effect; it will not move a build on its own.
• If color mixing is the goal, test each switch separately before combining colors so you can identify a faulty channel.

Replacement parts vs. kits: how to decide

The cheapest path is not always the smallest purchase. A single Gearbox - #6585 or Tire - 30.4 x 14 - #92402 solves one broken or lost piece at a low catalog price. But if you are missing several mechanical parts, the Gears Go Kit includes 71 parts plus three electronic Cubes, which covers motors, gears, wheels, and LEDs in one order.

Use this rule: if you can name the exact part number you need, buy that part. If you are guessing, or if more than one category is missing, buy a kit. The catalog prices shown here are comparison prices, so check the current listing before you order.

• Buy individual parts for known replacements; buy kits when you need multiple categories or want spares.
• Keep a small spares box with at least one gearbox, one tire, and spare axles so a lost part does not stop play.

Decision rules for buying Circuit Cubes parts

• If you need power and motion: Choose the Cube Combo. It includes the Battery Cube and Geared Motor Cube, so you get a complete powered circuit rather than two separate purchases. Best first buy for a moving build.
• If you need gears, wheels, and axles: Choose the Gears Go Kit. Its 71 parts include bricks, wheels, gears, and axles plus three electronic Cubes, which covers several categories in one order. Best value when more than one part type is missing.
• If you know the exact broken part: Buy the individual replacement, such as Gearbox - #6585 or Tire - 30.4 x 14 - #92402. Match the part number and stated size to the part you are removing. Cheapest fix for a known failure.
• If you want light but not motion: Add the RGB LED Cube only if you already own a battery and motor. The catalog states it is one part of a circuit and needs a battery to power it. An add-on, not a starter product.
• If a build will not run: Check connections and battery power before buying anything. Reseat wires, confirm the battery switch is on, and test the motor directly to isolate the faulty part. Diagnose before you replace.

Product facts to know before you buy

• Cubit Motor Cube: Catalog description: compact and powerful geared motor; internal planetary gears reduce the high-speed motor to about 160 RPMs to provide torque to gears and wheels; three ports around the motor connect wires from the Bluetooth Cube; includes one Cubit Motor Cube and custom axles in 10mm and 14mm. This is the right replacement when your build needs more pulling power or when a motor has failed. The three ports give you routing flexibility, and the included axles mean you can mount it without buying extra hardware.
• Cube Combo: Catalog description: includes the classic Battery Cube, which delivers approximately 3.7–4.2 volts DC when switched on, plus the Geared Motor Cube, which rotates at more than 1,000 RPM before its internal gears reduce speed. Buy this when you need both power and motion in one purchase. It is the fastest way to get a moving build, and the voltage detail helps you understand why the battery is the foundation of every circuit.
• Gears Go Kit: Catalog description: a multi-vehicle launch kit with a rechargeable Battery Cube, Motor Cube, RGB LED Cube, and 71 total parts including bricks, wheels, gears, and axles; builds at least five different vehicles. This is the best value when you need several categories at once. It covers motors, gears, wheels, and LEDs, so it works as both a starter kit and a spare-parts source.
• RGB LED Cube: Catalog description: contains red, green, and blue LEDs in one bulb with small switches to turn each on and mix colors such as purple, teal, and yellow; it is one part of a circuit and needs a battery to power it and a motor to make a build move. Add this when you want light effects, but do not expect it to power or move a build by itself. It is an add-on for builders who already own a battery and motor.

Will these parts fit your build?

Best for

• Builders who already own a battery and need a replacement motor, gearbox, tire, or LED
• Families who want one kit that covers motors, gears, wheels, and LEDs
• Anyone replacing a part with a known part number such as #6585 or #92402

Not for

• Buyers who have not identified which part is actually broken — diagnose first
• Builders expecting a standalone toy from the RGB LED Cube, which needs a battery and motor
• Anyone assuming generic wires or connectors will fit; the catalog does not list a separate wire part with specifications

Buy the exact part when you know what failed, buy the Cube Combo when you need power and motion, and buy the Gears Go Kit when you need several categories at once. Check the part number, the stated size, and the connector points before ordering, and keep a few spares on hand so a lost gearbox or tire does not end a build day.