System Integration
Overview
In this section, I document how all parts of my final project — the Smart Desktop Filament Winder — are integrated into a fully working, finished, and enclosed machine. This includes the mechanical design, electronics, user interface, sensors, and power system working together.
Packaging and Enclosure
The design is inspired by the Roland DE-3 desktop engraver, featuring a fully enclosed structure with a transparent front panel and top-loading access. I used 20x20 aluminum profiles as the frame, CNC-milled polycarbonate for side and top panels, and laser-cut acrylic for the UI panel.
- All electronics are mounted on an internal acrylic control panel.
- Spool holder and carriage system are mounted cleanly with no exposed belts.
- Wires are routed inside the frame using clips and sleeves.
UI & Control Panel
The user interface is located on the top-right of the machine and includes:
- 2.42" OLED Display (I2C)
- 1 Tactile Buttons:
Up,Down,Select,Back - Power indicator LED
- Emergency Stop Button (planned)
The user can select desired filament thickness and winding mode through the display menu. Settings are updated live and sent to the stepper control loop on the ESP32-C3.
Electronic Integration
All components are wired into a custom PCB based on the Seeed Studio XIAO ESP32-C3. It includes:
- 2x A4988 stepper drivers (for spool and pitch axes)
- Limit switch input for pitch homing
- Beam break sensor to count spool revolutions
- I2C communication for OLED display
- One tactile button for confirming actions (wired to GPIO)
- One potentiometer for analog pitch adjustment (wired to A0 / GPIO20)
- 12V DC power input with an inline rocker switch
System Wiring Diagram
The image below illustrates the full system integration: stepper motors, drivers, sensor, limit switch, OLED, single button, and potentiometer — all wired to the XIAO ESP32-C3.
This schematic shows all final connections in the working prototype. The system enables user interaction through one rotary control (potentiometer) and one confirmation button. The OLED display gives real-time feedback, while stepper drivers receive commands via STEP/DIR pins from the ESP32-C3.
System Behavior
At startup, the system homes the carriage via limit switch. The user sets the desired filament pitch. When winding starts:
- Pitch axis moves according to step size
- Spool motor rotates
- Beam break sensor counts revolutions
- System stops once set count is reached
Design as a Product
Effort was made to design the final machine as a manufacturable and user-friendly product:
- Compact size, clean layout, all wiring hidden
- Button and OLED placement easily reachable
- Modular parts for quick assembly and debugging
Final CAD render showing packaging and UI layout, inspired by Roland DE-3.
Inspiration: Roland DE-3
The design and packaging of my Smart Desktop Filament Winder were strongly inspired by the Roland DE-3 Desktop Engraving Machine.
I was particularly influenced by its fully enclosed acrylic body, clean internal wiring, and dedicated external control interface. I adopted a similar layout by:
- Using a transparent enclosure to keep moving parts visible but protected
- Mounting the control interface (OLED screen and buttons) flush into the front panel
- Routing all electronics and wiring internally to maintain a neat and professional look
- Planning for a large emergency stop button in an accessible position, just like the DE-3
The goal was to give the machine a product-like appearance while also maintaining accessibility for debugging and modularity, similar to what the DE-3 achieves in the desktop fabrication industry.
Bill of Materials (BOM)
Total estimated cost: $121.10 USD
| Component | Qty | Material/Type | Fabrication | Unit Price (USD) | Total Price (USD) |
|---|---|---|---|---|---|
| 20x20 T-slot Aluminum Profile (500mm) | 4 | Aluminum | Cut to length | $4.00 | $16.00 |
| M5 T-slot Nuts | 20 | Steel | Off-the-shelf | $0.10 | $2.00 |
| M5 Screws & Washers | 20 | Steel | Off-the-shelf | $0.05 | $1.00 |
| Spool Holder Arms | 2 | PLA | 3D Printed | $0.50 | $1.00 |
| Linear Carriage | 1 | PLA | 3D Printed | $1.00 | $1.00 |
| 8mm Trapezoidal Rod (T8, 300mm) | 1 | Steel | Off-the-shelf | $4.00 | $4.00 |
| Trapezoidal Nut (T8) | 1 | Brass/Nylon | Off-the-shelf | $2.00 | $2.00 |
| Coupler (Motor to Rod) | 1 | Aluminum | Off-the-shelf | $1.50 | $1.50 |
| Bearings (608ZZ) | 4 | Steel | Off-the-shelf | $0.80 | $3.20 |
| 8mm Linear Rod | 1 | Steel | Off-the-shelf | $3.00 | $3.00 |
| Electronics Mount Plate | 1 | Acrylic | Laser Cut | $1.00 | $1.00 |
| UI Panel | 1 | Acrylic | Laser Cut | $1.00 | $1.00 |
| Enclosure Panels | 4 | Polycarbonate | CNC | $6.00 | $24.00 |
| Spool Base Plate | 1 | Polycarbonate | CNC | $3.00 | $3.00 |
| Seeed Studio XIAO ESP32-C3 | 1 | MCU | Off-the-shelf | $6.00 | $6.00 |
| A4988 Stepper Driver | 2 | Driver | Off-the-shelf | $1.50 | $3.00 |
| NEMA17 Stepper Motor | 2 | Motor | Off-the-shelf | $13.00 | $26.00 |
| Power Supply | 1 | Adapter | Off-the-shelf | $8.00 | $8.00 |
| Beam Break Sensor (TCRT5000) | 1 | Sensor | Off-the-shelf | $1.00 | $1.00 |
| Limit Switch | 1 | Switch | Off-the-shelf | $0.50 | $0.50 |
| OLED Display (2.42\" I2C SSD1306) | 1 | Display | Off-the-shelf | $2.50 | $2.50 |
| Push Button (Tactile) | 1 | Input | Off-the-shelf | $0.10 | $0.10 |
| Potentiometer (10kΩ) | 1 | Input | Off-the-shelf | $0.50 | $0.50 |
| Custom PCB | 1 | PCB | Fabricated | $5.00 | $5.00 |
| JST / Header Connectors | 20 | Connectors | Off-the-shelf | $0.10 | $2.00 |
| Wires (22 AWG assorted) | 1 | Wiring | Off-the-shelf | $2.00 | $2.00 |
| Heat Shrink Tubing | 1 | Insulation | Off-the-shelf | $1.00 | $1.00 |