HKD CNC GRBL Shield V3 for Arduino UNO Drives 4x A4988 Stepper Drivers

The HKD CNC GRBL Shield V3 is a versatile expansion board designed for Arduino UNO, enabling precise control of 4 stepper motors using A4988, DRV8825, or other compatible stepper driver modules. This shield is GRBL 0.8c compatible, making it ideal for CNC machines, 3D printers, laser engravers, and other motion-control projects. By turning G-code commands into stepper motor signals, it allows you to automate movements with high accuracy and repeatability.

This compact and durable shield can drive up to four stepper motors (X, Y, Z, and an optional A-axis) and provides six general-purpose I/O pins for additional functionality such as spindle control, coolant control, or endstop inputs. The board supports microstepping adjustments via jumpers, allowing smooth and precise motor movement with resolutions up to 1/32 steps (depending on the driver used).

Key Features

GRBL 0.8c compatible open-source firmware for Arduino UNO

Supports 4-axis CNC control (X, Y, Z, A)

Drives up to 4 stepper motors using Pololu-compatible drivers

Compatible with A4988, DRV8825, and similar stepper drivers

Endstop support: 2 per axis (6 total) for accurate homing

Spindle and coolant control outputs

Adjustable micro-stepping via onboard jumpers

Motor connections via 4-pin Molex connectors or solder points

Operates on 12V-36V DC (depending on driver capability)

Compact, open-source design, easy to integrate into DIY projects

Expansion Board Pin-Out

8 EN (Stepper driver enable, active low)

7 Z.DIR (Z-axis direction control)

6 Y.DIR (Y-axis direction control)

5 X.DIR (X-axis direction control)

4 Z.STEP (Z-axis step control)

3 Y.STEP (Y-axis step control)

2 X.STEP (X-axis step control)

Optional D12 and D13 pins can be used for a full 4th axis or duplicated X/Y/Z axes with custom firmware.

Applications

DIY CNC engraving machines

3D printer stepper control

Laser engraving and cutting machines

Automated motion-control systems

Robotics projects requiring precise stepper movement

The HKD CNC GRBL Shield V3 is perfect for makers and engineers looking for a plug-and-play solution to convert G-code into precise stepper motor motion, providing full compatibility, reliable performance, and a compact design for a wide range of CNC applications.

What's in the box
1 x HKD CNC GRBL Shield V3 for Arduino UNO Drives 4x A4988 Stepper Drivers