The EDU Kit is a modular plastic recycling system built from autonomous, interchangeable building blocks - currently in development.

Each module handles one stage of the recycling chain — shredding, grinding, injection, extrusion, filament winding, pelletising, or sheet pressing — and can operate independently or be combined into complete processing lines.

The design principle is simple: every module fits the same physical footprint, shares the same drive interface, and connects to the same control bus. Rearrange them for a different task. Add a module when you need it. Remove one when you don't.

This is not a single machine. It is a system of machines that grows with your needs and your understanding.

Why Modular?

Traditional recycling machines are monolithic — large, fixed-purpose, and difficult to adapt. The EDU Kit inverts this by separating each processing step into a standalone unit:

• A school might start with a single shredder and a grinder, then add an injector the following year.
• A university lab runs the full chain — shredding, extrusion, filament winding, and pelletising — for materials research.
• A restaurant or hotel installs a compact shredder + grinder pair tucked against a wall, processing their own plastic waste on-site.
• A fab lab combines the extruder with the filament winder to produce custom 3D printing filament from recycled stock.

Every configuration starts with the same building blocks. Every block works alone. Every block works together.

The Modules

G — Grinder (EDU-GR)

A single-shaft granulator that reduces shredded plastic into uniform flake or fine regrind. 1500 W motor, 25 kg. Uni-housing compatible.

What it teaches: Cutting geometry, screen sizing, particle size distribution, and motor load curves. The grinder is the simplest module to understand mechanically — and the one where students first observe how material properties (hardness, elasticity) directly affect processing behaviour.

INJ — Injector (EDU-INJ)

Manual plunger injection module. 2300 W across multiple heating zones, 70 kg. Uses the shared main shaft for plunger drive.

What it teaches: The full injection cycle — barrel heating, melt behaviour, plunger force, mould fill, cooling, and ejection. Students control every variable by hand: temperature setpoints, plunger speed, hold time. No automation hides the physics.

SH-S — Single-Shaft Shredder (EDU-SHR)

A compact single-shaft shredder for rigid plastics. 1500 W, 25 kg. Uni-housing compatible, bench-top ready.

What it teaches: Shear mechanics, blade geometry, feed rate vs. torque, and jam detection. The single-shaft design is easier to disassemble and inspect than dual-shaft systems — ideal for first encounters with cutting machinery.

SH-D — Dual-Shaft Shredder (EDU-SHRD)

Counter-rotating dual-shaft shredder for mixed and flexible plastics. 1500 W, 50 kg. Higher torque, handles films and elastomers.

What it teaches: Differential shaft speeds, counter-rotation mechanics, and how blade overlap affects throughput. The dual-shaft architecture handles materials the single-shaft cannot — comparing the two side by side is one of the most instructive exercises in the system.

Status: Experimental

M — Drive Module (EDU-DRI)

The shared motor unit. 1500 W, 17 kg. Provides the mechanical drive for any module that doesn't have its own integrated motor.

What it teaches: Power transmission, shaft coupling, torque multiplication through gearboxes, and motor sizing. The drive module makes the relationship between electrical power and mechanical work explicit — students calculate torque, RPM, and efficiency before connecting it to a processing module.

LX — Extruder (EDU-LX)

Screw extruder module. 2200 W, 15 kg. Produces continuous melt output for filament, beams, or downstream modules.

What it teaches: Screw conveying, compression zones, melt pressure, die swell, and temperature profiling along the barrel. The extruder is the module with the most variables — and the one where systematic experimentation (design of experiments) produces the most dramatic results.

Status: Experimental

E-FW — Filament Winder + Cooler (EDU-FW)

Downstream module for the extruder. Pulls, cools, and winds filament onto spools. 50 W, 10 kg.

What it teaches: Drawdown ratios, cooling rate vs. crystallinity, tension control, and spool winding geometry. The winder closes the loop between recycled plastic and 3D printing — students produce filament from waste and print with it the same day.

Status: Experimental — depends on Extruder (LX)

E-IC — Clamping Module (EDU-LC)

Injection clamping unit that pairs with the extruder for continuous injection workflows. 800 W, 35 kg.

What it teaches: Clamp tonnage calculation, platen alignment, mould locking mechanics, and the relationship between injection pressure and clamp force. This module turns the extruder into a semi-automatic injection system.

Status: Experimental — depends on Extruder (LX)

E-PC — Pellet Cutter (EDU-PC)

Cuts extruded strand into uniform pellets. 70 W, attaches downstream of the extruder or filament winder.

What it teaches: Strand cooling, cutting speed synchronisation, pellet geometry, and the difference between strand pelletising and underwater pelletising (conceptually — the EDU Kit uses strand cutting). Pellets are the universal feedstock; making them from recycled material completes the material loop.

Status: Experimental — depends on Filament Winder (E-FW) or Extruder (LX)

G-PC — Grinder Addon (EDU-PCI)

An accessory module for the grinder, extending its capabilities with additional cutting configurations or screen options.

Status: Experimental — depends on Grinder (G)

HL9000 — Control Bus (EDU-HL9000)

The central controller and power distribution hub. Based on the PolyMech Controller architecture (ESP32-S3, Modbus-RTU/TCP, Wi-Fi). 300 W – 1500 W power routing, 15 kg.

The HL9000 connects to every module over a shared communication bus, providing:

• Centralised temperature monitoring and PID control
• VFD motor speed management across modules
• Real-time data logging and web-based HMI
• Safety interlocks between connected modules
• OTA firmware updates for the entire system

What it teaches: Industrial bus protocols, SCADA architecture, distributed control systems, and the engineering challenge of coordinating multiple autonomous machines as a single system.

Status: Alpha

HS — Sheet Press Module (EDU-SPM)

Hydraulic sheet press for flat panels. 6000 W, 300 kg. The largest and most powerful module in the system.

What it teaches: Hydraulic pressure distribution, thermal uniformity across platens, compression moulding vs. injection moulding trade-offs, and composite layup with mixed materials.

Status: Experimental

Shared Architecture

Uni-Housing

Most modules share a common housing form factor. This is not just aesthetic — the uni-housing defines:

• Mounting interface — modules bolt together side-by-side or stack vertically
• Shaft pass-through — the main drive shaft can extend through multiple modules
• Electrical connectors — standardised power and signal connectors on every unit
• Safety enclosure — all moving parts are contained within the housing

The Main Shaft

Modules that require rotational drive (grinder, shredder, extruder) connect to a shared main shaft. The Drive Module (M) provides the power; the shaft transmits it through couplings. Students learn about:

• Shaft alignment and coupling types (jaw, rigid, flexible)
• Torque transmission through multiple modules
• The mechanical consequences of misalignment (vibration, bearing wear, heat)

Width and Footprint

Every module is designed to fit within a minimum width constraint. A full processing line — shredder → grinder → extruder → filament winder — occupies less than 2 metres of bench space. This matters for:

• Schools with shared workshop space
• Restaurants with limited back-of-house area
• Labs where bench space is more valuable than floor space

Configuration Examples

Classroom Starter

Modules: Grinder (G) + Drive (M)

Two modules, one shaft. Students shred pre-cut plastic samples and grind them into flake. Teaches motor control, particle size, and material identification. Fits on a single workbench.

Filament Production Line

Modules: Shredder (SH-S) + Grinder (G) + Extruder (LX) + Filament Winder (E-FW) + Drive (M) + HL9000

Full waste-to-filament chain. Shred → grind → extrude → cool → wind. The HL9000 coordinates temperatures and motor speeds across all modules. Students produce 3D printing filament from plastic waste.

On-Site Waste Processing (Hospitality)

Modules: Shredder (SH-S) + Grinder (G) + Drive (M)

A compact, quiet pair for processing plastic packaging waste. No extrusion, no injection — just size reduction. The output (clean regrind) is stored for collection or further processing off-site. Fits against a kitchen wall.

Research Lab — Full System

Modules: All modules + HL9000 + Sheet Press (HS)

The complete system. Researchers reconfigure the line for different experiments: injection studies one week, extrusion trials the next, sheet pressing the week after. The HL9000 logs every parameter for every run.

What Connects Everything: The HL9000 Bus

The HL9000 is not just a controller — it is the nervous system of the EDU Kit. Every module that connects to the bus becomes visible, controllable, and loggable from a single web interface.

The bus architecture is intentionally transparent:

• Modbus-RTU over RS-485 for motor drives and temperature controllers
• Modbus-TCP over Wi-Fi for remote monitoring and data export
• WebSocket for real-time HMI dashboards
• REST API for integration with external systems, data loggers, and cloud platforms

Students can tap into the bus at any level — from reading raw UART frames with a serial monitor to building custom dashboards in the browser. The firmware is open-source, documented, and version-controlled.

Design Priorities

1. Autonomy — Every module works alone. No module requires another to function (except where explicitly noted as a dependency).
2. Safety — Enclosed operation. Interlocked housings. Emergency stops on every module. No exposed moving parts during operation.
3. Repairability — Standard fasteners, replaceable wear parts, accessible internals. If a student can't disassemble it, it's not educational.
4. Transparency — Open-source hardware (CERN OHL v2), open-source firmware, full CAD files and BOMs. Nothing is hidden.
5. Compactness — The full system fits in a small workshop. Individual modules fit on a bench.

Status Overview

The EDU Kit is an active development project. Some modules are mature and production-tested; others are in experimental or alpha stages. The spec table below reflects the current state of each module — including mechanical specifications, maturity level, and documentation coverage.

Mature modules are ready for deployment. Experimental modules are functional prototypes undergoing refinement. Alpha modules are in early development.

Open Source

Every module in the EDU Kit is licensed under the CERN Open Hardware Licence v2. CAD files, firmware, assembly instructions, and BOMs are published at git.polymech.info. Community contributions — from students, teachers, and engineers — feed back into the project.

The EDU Kit is not a product you buy and forget. It is a system you build with, learn from, and improve.