nearxos f26f15db61 feat(pcb): add 8-belt CNC router board — FluidNC YAML config + schematic netlist
- esp32-s3-pinout.yml: complete FluidNC machine config for 4×axis, 2-motors-per-axis (8 TMC2209, UART mode)
- schematic_netlist.md: component-level connection table (ESP32-S3, TMC2209, power, connectors, BOM)
- pins derived from Maslow 4 ESP32-S3 board layout adapted for 4-axis gantry
- TMC2209s on 2 UART buses (GPIO17/18), 4 addresses each, VREF resistor matrix
2026-06-20 16:15:25 +03:00

CNC Router Project - Core Research & Comparative Analysis

1. Executive Summary & Design Goal

The goal of this project is to research and evaluate the design of a highly portable, cost-effective CNC router for semi-professional and DIY woodworking. Traditonal gantry CNC systems require massive frames, expensive linear rails, ballscrews, and a large dedicated workshop footprint.

This project pursues a rail-free, multi-belt/cable-driven suspended or surface-riding kinetic motion system. The final design should merge the portability and workspace flexibility of Cubiio X / Gordix with the open-source firmware accessibility and robust DC servo architecture of the Maslow 4.


2. Competitive Landscape: Comparative Analysis

Feature / Metric Gordix (Muherz) Maslow 4/4.1 (Bar Smith) Cubiio X (Muherz) Maker Made M2 Cubiio (Laser Only)
Motion Concept Rail-free, surface-riding sled Flat-rigid-surface riding sled Rail & Ballscrew compact robot Frame-suspended sled Fixed head laser projector
Kinetic Drive 8-Belt drive system 4-Belt drive system 4 Timing belts + linear rails 2 Roller chains None (optical galvo)
Belts / Chains 8x High-stress fiberglass timing belts 4x High-tensile braided Dyneema/UHMWPE line 4x Gates rubber timing belts 2x Metal roller chains None
Drive Motors 8x Sled-mounted motors (calculated) 4x Sled-mounted 24V DC geared servo motors 4x Independent stepper/geared motors 2x Frame-mounted DC geared motors + encoders Gauges / galvos
Workspace Capacity Up to 4' x 8' (1.2m x 2.4m) Up to 4' x 8' (1.2m x 2.4m) Up to 4' x 4' (1.2m x 1.2m) Up to 4' x 8' (1.2m x 2.4m) Sized by lens focal limit
Sled Rotation Control Constraint-locked by 8-belt geometry (Prevents yaw) Sled rides material, yaw resolved mathematically Standard Cartesian inside frame Gravity & heavy sled-mass pivot (2-point) Fixed
Weight ~4.3 kg (very portable) ~7-8 kg Moderate, highly integrated Very heavy (sled + steel chains) ~1.5 kg
Spindle / Cutting Head 3-in-1: Wood router (Makita body), 10W Laser, Pen Wood router (Makita RT0701C / Bosch 1617) Customized miniature spindle plus 10W laser Standard Wood router (Dewalt/Makita) laser diode
Software & Firmware Gordix Studio (Proprietary / Closed CAM Web Tool) FluidNC (Custom ESP32 branch), fully open-source Proprietary G-code sender / parser (restricted lines) Makerverse / GRBL Cubiio App
Homing & Calibration Self-calibrating / anchor reference Self-calibrating (spooling tight to frame anchors) Manual alignment Manual/Chain measurement calibration Optical calibration
Est. Retail Cost ~$1,700 - $3,000 USD ~$650 USD (Kit form) ~$1,250 - $1,900 USD ~$600 USD ~$400 - $800 USD

3. Core Mechanics & Kinematics Study

3.1 Understanding the 4-Belt vs 8-Belt Kinematics

  1. The 4-Belt Limitation (Maslow 4 / Cubiio X):
    • A 4-belt system pulls the sled toward the four corners of the workspace. If the anchor points for the belts are not at the exact mathematical cutting center of the router spindle nozzle, the lateral pulling force induces yaw rotation (sled rotation).
    • Sled rotation introduces substantial mathematical calculation complexity (since the rotation angle changes dynamically across the workspace) and can degrade dimensional accuracy.
    • Additionally, near the corners, a 4-belt system loses tension on one or more belts, causing sag, loss of downforce, or physical slippage.
  2. The 8-Belt Triumph (Gordix Concept):
    • Gordix utilizes an 8-belt architecture where a twin pair of belts splits to each of the 4 workstation corners.
    • By running two parallel belts to each corner, the system creates a rigid geometric lock that naturally constrains yaw (sled rotation) without requiring software mathematical triangulation of rotational drift.
    • Sled orientation remains perfectly constant relative to the cutting boundaries, keeping tension balanced across the entire 4'x8' workspace.

3.2 The Levitating 3D "Sky Spider" Concept

During research of the Maslow community archives, an intriguing alternative design was documented: "Project Sky Spider" / "M8 Concept".

  • Standard sled designs must ride directly on top of the woodworking piece. This introduces challenges with friction, wood chips jamming under the sled, scratching the surface of delicate veneered materials, or getting stuck on pre-carved pockets.
  • The Sky Spider concept uses 8 highly tensioned belts (or 4 pair in vertical-opposing 3D diagonals) to float and hover the entire CNC routing head in 3D space over the material.
  • Mechanical requirements for suspended operation:
    • Redesigning spool anchors with ball-joint (like a CV joint) to rotate freely in 3D.
    • Adding a robust, heavy outer boundary frame.
    • Using longer Z-axis lead screws to drop down into the material from the hovering carriage.

4. Software & Firmware Strategy

An open-source, highly customizable software stack is a hard requirement for this DIY/semi-professional project to avoid the limitations of proprietary systems like Gordix Studio or Cubiio.

  • FluidNC is the undisputed gold standard for ESP32/ESP32-S3-based kinetic motion controllers.
  • It is a highly optimized rewrite of GRBL-ESP32 utilizing a modular, C++ architecture.
  • Why it fits our project:
    • FluidNC supports web page uploading, Wi-Fi Direct (AP Mode), Bluetooth Send, and Telnet on top of standard hardware serial over USB.
    • It handles multi-axis motor groupings, custom kinematics (such as wallplotter or CoreXY), H-bridge drivers directly, and SPI/I2C communication.
    • Since the Maslow 4 firmware is a direct fork of FluidNC, porting the mathematical kinematics for a custom 4-belt or 8-belt kinematics into FluidNC is well-documented and highly achievable.
Description
CNC Router research and design documentation. Portable CNC router for woodworking, inspired by Gordix, Maslow, Maker Made M2, Cubiio X.
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