Mach3 USB Interface Board

Mach3 USB CNC Controller Board

Control a Mach3-based CNC machine through USB instead of relying on an older parallel-port computer. This Mach3 USB CNC controller board is a practical motion-control option for DIY CNC routers, CNC mills, plasma tables, retrofit control boxes, and replacement use in the Woodsmith CNC Kit.

This board ships inside every Woodsmith CNC Kit. If you are building from that kit, you already have one. If you are retrofitting an existing machine or replacing a failed board, this is the direct replacement controller board.

Best For

• DIY CNC router builds using Mach3 control software
• Woodsmith CNC Kit replacement controller boards
• CNC routers, CNC mills, plasma tables, and retrofit control boxes
• Replacing older parallel-port motion-control setups with USB connectivity
• Mach3-based CNC electronics and controller upgrade projects

What's Included

• Mach3 USB Interface Board
• USB Cable

Software compatibility: This controller board runs with Mach3 CNC control software. Mach3 can be tested in Demo mode with limitations, while a purchased license unlocks the full version for complete CNC machine operation.

Need a full Mach3 license? BuildYourCNC sells official Mach3 CNC control software licenses compatible with this USB controller board. View Mach3 CNC software.

Setup Downloads for Existing Board Owners

Already have this Mach3 USB CNC controller board? Download the required Mach3 USB motion plugin and configuration file below:

• USB Motion Plugin - RnRMotion.dll
• Mach3Mill.xml Configuration File - right-click and select “Save As”

Basic Mach3 USB Board Setup Instructions

1. Install Mach3. Install Mach3 CNC control software. Mach3 may be tested in Demo mode with limitations, or unlocked with an official purchased license.
2. Install the USB motion plugin. Download the RnRMotion.dll file and copy it into your Mach3 Plugins folder. This is typically located at C:\Mach3\PlugIns.
3. Connect the controller board. Plug the Mach3 USB controller board into your computer using the included USB cable.
4. Load the Mach3 configuration file. Download the Mach3Mill.xml file (right-click and select “Save As”), save it to your Mach3 root folder, then open Mach3.
5. Select the controller plugin. When Mach3 prompts you, select RnRMotionController. Check “Don’t ask me again” so Mach3 uses this controller automatically.

Important: Limit switches and the spindle-control section of the board require an additional power source. Do not assume the USB connection alone powers every external device connected to the board.

Technical Features

• USB connection for Mach3 CNC control
• Compatible with Windows XP, Windows 7, and Windows 10 systems
• Supports up to 4-axis linkage control
• 4th axis can be configured as a slave axis
• 100K pulse output
• Minimum-error interpolation for smoother motion control
• Automatic homing support
• Slave-axis auto-leveling during homing
• Automatic tool-setting support
• Emergency stop input
• Limit switch input support
• Spindle control using PWM mode or relay mode
• 4 optocoupler-isolated digital signal inputs
• Up to 12 total digital signal inputs
• 4 optocoupler-isolated relay outputs
• Handwheel interface support
• Interference-resistant design with industrial components

Compatible Products

• Mach3 CNC Control Software License - official Mach3 software license for unlocking the full version used with this controller board
• Woodsmith CNC Kit - complete CNC machine kit that includes this Mach3 USB controller board

Setup and Support Videos