CNC Shield V3 for Arduino Uno – A4988 / DRV8825

CNC Shield V3 for Arduino Uno

Bring your DIY CNC engraving project together with a compact stepper-driver expansion board for the Arduino Uno. The CNC Shield V3 provides four driver-module slots, end-stop connections, spindle control and coolant enable connections, helping you organise your machine's control wiring in one place.

Designed for removable A4988 and DRV8825 stepper-driver modules, this shield works with an Arduino Uno running compatible GRBL firmware. Stepper-driver modules are not included.

Key features

• Four driver slots: supports X, Y and Z axes, plus a configurable A-axis slot.
• Flexible A-axis setup: duplicate X, Y or Z, or use custom firmware for independent fourth-axis operation through pins D12 and D13. Independent four-axis control is not a standard GRBL feature.
• End-stop connections: two connections per axis for X, Y and Z, six in total.
• Machine-control connections: spindle enable/PWM and direction pins, plus coolant enable. Pin assignments must match your shield revision and firmware.
• Microstepping selection: jumper settings configure the installed driver's microstepping mode; DRV8825 drivers can support up to 1/32 microstepping.
• Motor connections: connect stepper motors using 4-pin Molex connectors or soldered connections.
• Step/direction control: each stepper driver uses two control signals.

Compatibility and power

• Controller: Arduino Uno.
• Driver modules: removable A4988 / DRV8825-compatible modules, sold separately.
• Firmware: the existing product specification lists GRBL 0.9 compatibility. Confirm the pin mapping before connecting spindle or limit-switch wiring.
• Shield motor-power input: 12–36V DC, subject to the installed driver's limits. Do not apply 36V to an A4988 driver; select the supply voltage to suit the driver and motor.

Applications

Use this shield as the driver expansion board in a DIY CNC machine or engraving setup. It can also be used in other stepper-controlled projects, including compatible 3D-printer builds, when paired with suitable firmware and electronics.

Before you build

The existing listing identifies this as an unassembled kit requiring soldering. Check driver orientation, current-limit settings, power-supply voltage and firmware pin assignments before powering your assembly. The Arduino Uno, driver modules, motors and power supply are required separately for a working setup.