Mechanical Design

2. Mechanical Design

2.1 CAD Design

All mechanical components were designed in Fusion 360 with modularity and manufacturability in mind. The frame is built from 20x20 T-slot aluminum profiles. Mounts and fixtures are mostly 3D printed using PLA, while enclosure and structure panels are laser-cut from acrylic or CNC-milled from polycarbonate.

2.2 Key Mechanical Features

• Winding Axis: NEMA17 motor rotates the filament spool; rotation is counted using a beam break sensor.
• Pitch Axis: A second NEMA17 motor drives a carriage along an 8mm trapezoidal threaded rod using a T8 nut.
• Limit Switch: Provides homing functionality for the pitch axis.
• Linear Carriage: Slides on an 8mm rod and is supported by bearings.
• Frame: Constructed using 20x20 aluminum profiles for rigidity and ease of assembly.

2.3 Fabrication Methods

• 3D Printing (PLA): Used for motor mounts, carriage, sensor brackets, and spool holders.
• Laser Cutting (Acrylic): Used for the electronics panel and UI faceplate.
• CNC Machining (Polycarbonate): Used for structural side panels and base platform.

2.4 Mechanical BOM

Component	Qty	Material	Fabrication	Notes
20x20 T-slot Aluminum Profile	4–6	Aluminum	Cut to length	Main structure
M5 T-slot Nuts	~20	Steel	Off-the-shelf	Frame assembly
M5 Screws & Washers	~20	Steel	Off-the-shelf	Mounting and securing
Spool Holder Arms	2	PLA	3D Printed	Holds filament spool in place
Linear Carriage	1	PLA	3D Printed	Slides on linear rod
8mm Trapezoidal Threaded Rod	1	Steel	Off-the-shelf	Drives pitch axis
Trapezoidal Nut (T8)	1	Brass/Nylon	Off-the-shelf	Thread engagement
Coupler (Motor to Rod)	1	Aluminum	Off-the-shelf	Connects motor to rod
Bearings (608ZZ)	2–4	Steel	Off-the-shelf	Supports rod rotation
8mm Linear Rod	1	Steel	Off-the-shelf	Guides carriage
Electronics Mount Plate	1	Acrylic	Laser Cut	Holds PCB and screen
UI Panel	1	Acrylic	Laser Cut	OLED and button interface
Enclosure Panels	3–5	Polycarbonate	CNC	Protective casing
Spool Base Plate	1	Polycarbonate	CNC	Under the rotating spool