CNC V3 Shield with 4 A4988 Drivers
CNC V3 Shield with 4 A4988 Drivers
Complete Arduino-compatible CNC controller for 3D printers and milling machines
Introduction
The CNC V3 Shield is an all-in-one motion control solution that combines an Arduino-compatible microcontroller with four A4988 stepper motor drivers. This robust shield provides everything needed to control CNC machines, 3D printers, or robotic applications with precision and reliability.
Key Features
4-Axis Control
X, Y, Z axes + 1 additional axis
Integrated Drivers
4 × A4988 stepper drivers
Microstepping
Up to 1/16 step resolution
Fan Control
Dedicated PWM fan output
Heat Management
Large heatsinks + cooling fan
Endstop Inputs
3-axis limit switch connectors
Technical Specifications
| Compatible Boards | Arduino Uno, Mega, Duemilanove |
|---|---|
| Stepper Drivers | 4 × A4988 (replaceable) |
| Motor Outputs | 4 axes (X,Y,Z,A) |
| Max Current per Axis | 2A (with cooling) |
| Microstepping | Full, 1/2, 1/4, 1/8, 1/16 |
| Power Input | 12-36V DC (recommended 24V) |
| Logic Voltage | 5V (from Arduino) |
| Spindle Control | PWM + direction |
| Fan Output | 12V PWM (max 1A) |
| Endstop Inputs | 3 × mechanical endstops |
| Dimensions | 68.6mm × 53.3mm |
Pin Configuration
| Connector | Function | Arduino Pin |
|---|---|---|
| X.STEP | X-axis step pulse | D2 |
| X.DIR | X-axis direction | D5 |
| Y.STEP | Y-axis step pulse | D3 |
| Y.DIR | Y-axis direction | D6 |
| Z.STEP | Z-axis step pulse | D4 |
| Z.DIR | Z-axis direction | D7 |
| A.STEP | A-axis step pulse | D12 |
| A.DIR | A-axis direction | D13 |
| FAN | Cooling fan PWM | D9 |
| SPINDLE | Spindle control | D11 |
Installation Guide
- Power Down: Disconnect all power sources
- Mount Shield: Align and press onto Arduino headers
- Insert Drivers: Place A4988 drivers in sockets (observe orientation)
- Connect Motors: Wire steppers to appropriate axis terminals
- Power Input: Connect 12-36V DC to power terminal
- Endstops: Connect limit switches if used
- Cooling: Connect fan to FAN output
Current Adjustment
Procedure
- Power off and disconnect motors
- Set multimeter to 200mV DC range
- Place probes on driver potentiometer and GND
- Power on system
- Adjust until VREF = I_Trip × 0.8
- Repeat for each driver
Example Settings
- NEMA 17 (1.2A): 0.96V
- NEMA 17 (1.5A): 1.2V
- NEMA 23 (1.7A): 1.36V
- NEMA 23 (2.0A): 1.6V
GRBL Configuration
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 |
// Sample GRBL settings for CNC V3 Shield $0=10 // Step pulse, microseconds $1=25 // Step idle delay, milliseconds $2=0 // Step port invert, mask $3=0 // Direction port invert, mask $4=0 // Step enable invert, boolean $5=0 // Limit pins invert, boolean $6=0 // Probe pin invert, boolean $10=3 // Status report, mask $11=0.010 // Junction deviation, mm $12=0.002 // Arc tolerance, mm $13=0 // Report inches, boolean $20=0 // Soft limits, boolean $21=0 // Hard limits, boolean $22=0 // Homing cycle, boolean $23=0 // Homing dir invert, mask $24=25.000 // Homing feed, mm/min $25=500.000 // Homing seek, mm/min $26=250 // Homing debounce, milliseconds $27=1.000 // Homing pull-off, mm |
Troubleshooting
Motors Not Moving
- Check power supply voltage
- Verify driver installation
- Test step/direction signals
- Confirm current settings
Overheating Drivers
- Reduce motor current if possible
- Ensure cooling fan is working
- Check for short circuits
- Improve ventilation
Inconsistent Movement
- Verify microstep settings
- Check motor wiring connections
- Ensure sufficient power supply
- Test with different GRBL settings
Application Examples
3D Printers
Cartesian and CoreXY configurations
CNC Routers
Small to medium-sized milling machines
Robotics
Multi-axis robotic arms
Plotters
Laser engravers and pen plotters
