Mechanical design, machine design

Mechanical design (part 1 of 2)

Group assignment:

• Design tomachine which includes mechanism + actuation + automation + app
• Build the mechanical parts and operate them manually.
• Document the group project.

Individual assignment:

• Document your individual contribution

Machine design (part 2 of 2)

Group assignment:

• Take action and automate your machine.
• Document the group project.

Individual assignment:

• Document your individual contribution

Link to the group page https://fabacademy.org/2026/labs/lima/MachineWeek.html

Aim

Design, build and validate a biomaterial shredding machine oriented towards the production of bio-paper, integrating cutting mechanisms, power transmission and mechanical structure, with experimental validation of the processing of organic fibers and projection towards its automation as part of a sustainable manufacturing system.

A LITTLE CONTEXT ABOUT OUR MACHINE….

GROUP ASSIGNMENT

Initial Project Brainstorming and Conceptualization Collaborative Ideation and Definition

This image captures the foundational moment of the project where all team members participated in a dynamic brainstorming session to define the scope and function of the "Smart Shredder." During this phase, critical input regarding machine operation from Esteban Valladares and Carmen Gutierrez helped shape the initial mechanical concepts. The entire group collaboratively sketched and debated various ideas on the whiteboard, aiming to integrate the machine's capabilities with a clear purpose. Grace Schwan, Mario Chong, and Rocio Maravi meticulously tracked these discussions to begin the official technical documentation, ensuring that every idea was logged for future reference.

Defining the Core Purpose and Material Workflow

A key output of this collaborative session was defining the primary use-case for the shredder: processing specific bio-fibers to create sustainable materials like "Bio-Paper." Cindy Crispin's preliminary research on local fibers—such as Yuca, Coconut, Platano, and Piña—was vital in steering the machine's functional requirements towards sustainable material development. Jianfranco Bazan analyzed this workflow to begin identifying necessary sensor integration and automation requirements for regulating the cooking and blending processes outlined. This comprehensive diagram serves as the master conceptual blueprint, aligning all members on the machine's purpose before proceeding to CAD modeling and electronic prototyping.

Expanded Design Thinking Documentation

1. Phase: Empathize (Understand)

The foundation of the Smart Shredder was built through deep research into sustainable manufacturing. Cindy Crispin led the investigation into local bio-fibers, such as banana and pineapple, to understand the needs of the circular economy. To ensure this knowledge was preserved, Grace Schwan, Mario Chong, and Rocio Maravi began the systematic recording of these findings, creating the first entries of our project log. This collaborative effort allowed the team to empathize with users who require accessible tools for organic waste processing.

2. Phase: Define (Understand)

In the definition phase, the team synthesized research into technical requirements. Cindy Crispin defined the physical parameters for material testing, while the documentation team (Grace, Mario, and Rocio) structured these goals into a formal project scope. This phase ensured that Jianfranco Bazan (Electronics) and the design team (Esteban and Carmen) had a clear set of constraints to work within, focusing the project on creating an automated, user-friendly solution for "Bio-Papel" production.

3. Phase: Ideate (Explore)

During ideation, the team translated concepts into technical sketches. Esteban Valladares and Carmen Gutierrez led the mechanical brainstorming, focusing on the shredder's operability and blade geometry. Jianfranco Bazan contributed by ideating the integration of smart sensors into the workflow. Throughout this creative process, Grace, Mario, and Rocio acted as the "memory" of the team, documenting every sketch and discarded idea to provide a transparent record of how the final design was reached.

4. Phase: Prototype (Explore)

The prototype phase saw the project take physical form through digital fabrication. Esteban Valladares and Carmen Gutierrez used CAD/CAM tools for the modeling and manufacturing of the chassis and blades, with Esteban ensuring the correct operability of the FabLab machines. Simultaneously, Jianfranco Bazan developed the electronic control systems and PCB. The documentation team (Grace, Mario, and Rocio) captured this progress through photography and technical writing, while Cindy Crispin prepared the first sets of raw materials for the initial physical tests.

5. Phase: Test & Implement (Materialize)

In the final stage, the "Smart Shredder" underwent rigorous validation. Cindy Crispin led the material testing, verifying the quality of the shredded pulp, while Jianfranco Bazan fine-tuned the programming based on the mechanical performance. Esteban Valladares supervised the machine's operability under stress to ensure safety. Finally, Grace Schwan, Mario Chong, and Rocio Maravi compiled all test results and technical data into the final documentation in VS Code, completing the cycle from initial idea to a functional, documented prototype.

Markdown Team Matrix (Ready for VS Code)

Team Member	Primary Responsibility	Design Thinking Focus
Esteban Valladares	Design, Modeling & Machine Ops	Ideate, Prototype, Test
Carmen Gutierrez	Design & Modeling	Ideate, Prototype
Jianfranco Bazan	Electronics & Programming	Ideate, Prototype, Test
Cindy Crispin	Research & Material Testing	Empathize, Define, Test
Grace Schwan	Technical Documentation	All Phases (Record/Log)
Mario Chong	Technical Documentation	All Phases (Record/Log)
Rocio Maravi	Technical Documentation	All Phases (Record/Log)

6. Conceptualization and Workflow Definition Project Brainstorming and Process Flow

This image captures the initial definition phase of the Smart Shredder project. The whiteboard sketch outlines the primary goal: creating "BIO-PAPER" (Bio-Paper) from organic waste. The specific material workflow is defined, focusing on using fibers from "Tronco del

Platano" (Banana Trunk), "Yuca" (Cassava), "Coco" (Coconut), and "Piña" (Pineapple). The diagram is crucial for establishing the necessary functional requirements for the machine, ensuring the resulting pulp meets the texture standards required for sustainable paper manufacturing.

Integrated Functional Requirements

Beyond material definition, the sketch lists the essential processing stages the shredder must facilitate: 1. Harvesting the Banana Trunk. 2. Fiber Chopping ("Chop the Fiber"). 3. Cooking the Fiber. 4. Fiber Blending ("Liquify the Fiber"). These manual stages inform the mechanical requirements of the shredder blades and the torque of the motor. This foundational document aligns the entire team—from Cindy Crispin's material research to Esteban and Carmen's mechanical design—on the single purpose of efficient, sustainable fiber preparation.

7. Mechanical Design and CAD Modeling Single Unit Shredding Component

The mechanical foundation of the shredder relies on repetitive, specialized blades to chop raw organic fibers efficiently. Esteban Valladares and Carmen Gutierrez led the development of these components in SolidWorks.

• Piece Description & Function: A single unit of the shredding stack. This part features an internal gear-like profile that aligns multiple units into a unified rotating shaft. The external profile is aggressive, designed to slice and rip tough fibers without clogging. Its modular design allows for future scale-up of the machine's capacity.
• Machine Integration: This unit is laser cut from metal for initial testing and later CNC machined for long-term durability. Multiple units are stacked tightly along the main hex shaft, separated by spacers, and integrated directly into the main cutting chamber.

Modular Blade Array CAD Assembly Blade Unit Matrix Development

To ensure uniform shredding across the entire cutting chamber, the modular blade units are organized into a precise matrix. Esteban and Carmen designed this stack in SolidWorks to analyze mechanical operability before physical fabrication.

• Piece Description & Function: This 3D CAD visualization showcases a stack of the modular cutting blades (from the previous block). It uses the Linear Matrix tool in SolidWorks to organize exactly 27 instances of the blade along a custom internal hex geometry. The model ensures there is zero interference between the blades and the main drive shaft while maintaining the optimal separation for fiber throughput.
• Machine Integration: The resulting hex-profile assembly is the primary rotating mass of the machine. It is designed to sit inside the custom designed shredding housing (detailed later), where it must rotate freely while engaging with the fiber hopper.

Main Cutting Chamber Housing

Integrated Shredder Housing and Motor Mount

The structural chassis of the Smart Shredder must provide robust support for the powerful cutting mechanism and the integrated motor. Esteban Valladares designed this multi-functional housing to ensure precise mechanical operability.

• Piece Description & Function: This complex 3D assembly, shown here in wireframe mode, serves as the main cutting chamber and the primary structural support. It features integrated mounting points for the high torque shredder motor and precision bores for the bearing blocks of both counter-rotating shafts. The top opening acts as the fiber hopper inlet, while the bottom is the processed pulp outlet.
• Machine Integration: This unit is CNC machined from robust, fiber reinforced polymers or metal (based on material testing) and bolted directly to the main machine chassis. The wireframe view ensures that internal tolerances, especially the tight clearance required between the blades and the chamber wall, are met before manufacturing.

8. Digital Fabrication and Component Prototyping Slicing for 3D Printing (CAM Preparation)

Additive Manufacturing Simulation and Support Structure

Before physical fabrication of critical functional parts, the CAD models must be prepared for digital additive manufacturing (3D Printing). Esteban Valladares managed this CAM preparation using Bambu Studio to ensure correct machine operability.

• Piece Description & Function: This image shows the mechanical component (likely a gear or a support structure) being finalized in the slicer software. The view reveals the generated support structures (the textured grid) required to print overhanging geometry without deformation. Crucial settings are defined, including material (ABS or Nylon), 0.20mm layer height, and a 15% grid infill, optimizing strength vs. material consumption for the rapid prototype.
• Machine Integration: This step is vital to ensure that the printed part will match the CAD dimensionally, especially where precision bores or gears are involved. Following the successful print, the support structures are meticulously removed, and the part undergoes dimensional verification before integration into the final assembly.

Printing Functional Power Transmission Components Rapid Prototyping of the Transmission System

The Smart Shredder's variable-speed requirement necessitates specialized gears, which must be rapidly prototyped for validation. This image captures the physical realization of these transmission components.

• Piece Description & Function: This real-time view shows a large, custom- designed drive gear being actively printed in high-temperature ABS filament. The gear features specialized internal reinforcement (visible in the top layers) to withstand the high torque transferred from the main motor to the shredder's hex shaft. Esteban Valladares monitored the process to ensure operability.
• Machine Integration: This printed gear is integrated into the external transmission housing, meshing directly with the motor pinion and the corresponding counter-shaft gear. It must provide smooth, high-torque power transfer for continuous shredding. The print monitoring is crucial for identifying any layering errors that could cause premature gear failure under load.

9. Mechanical Integration and Assembly Functional Transmission Assembly Final Gearbox and Motor Interface

With the CAM and 3D printing validation complete, the functional transmission components are integrated into the machine's external drive train. This crucial assembly converts motor speed to high torque for the cutting chamber.

• Piece Description & Function: The successful high-temperature ABS print of the custom transmission gear (from the previous section) is shown here permanently integrated into the external drive housing. The gear meshes seamlessly with the central drive pinion and sits on a custom hex adapter to drive the shredding shaft.
• Machine Integration: This gearbox assembly is bolted directly to the main motor face and then to the cutting chamber housing (detailed in previous CAD blocks). It is fully enclosed for safety, and the printed parts are lubricated to reduce friction, completing the machine's primary power train.

Complete Counter-Rotating Shredding Matrix Full Cutting Assembly Validation

This image shows the core of the Smart Shredder fully assembled: the dual, counterrotating blade arrays are complete and ready for final integration.

• Piece Description & Function: This view showcases the two complete blade dies—the 27-blade hex stacks modeled in SolidWorks. The entire assembly sits on its final main chassis base (shown here as a plywood prototype). The stacks are perfectly intermeshed and locked onto their custom-machined hex shafts. The integration with the main bearing blocks (white components) is validated, ensuring smooth, non-interfering rotation.
• Machine Integration: This entire intermeshed assembly is dropped into the custom polymer cutting chamber (from previous blocks). The motor/ gearbox is connected to one shaft, completing the mechanical operability test before the smart sensor array (from Jianfranco's role) is integrated.

15/04/2026

Mechanical Integration and Advanced Component Fabrication Preparation of Precision Transmissions

• Description & Function: This block showcases the advanced fabrication phase led by Esteban Valladares and Carmen Gutierrez. The high-grade polymer cutting chamber (from previous blocks) is now fitted with its precision bearing blocks (white components) and robust metal transmission mounts. These mounts are vital for accurately positioning the custom hex shafts and the 3Dprinted gears, ensuring minimal friction and high torque transfer. Esteban ensured the machine operability by validating the alignment of these metal-topolymer connections.
• Integration: These transmission mounts are bolted directly to the main shredder housing, creating the final powertrain interface for the high-torque motor.

Full Intermeshed Blade Stack Assembly

• Description & Function: This image marks the final structural integration of the cutting mechanism. The two counter-rotating hex shafts, equipped with the 27 intermeshed blades designed by Esteban and Carmen, are now permanently locked within the cutting chamber. The shafts are supported by the integrated precision bearing blocks (white). The complex geometry of the interlocking blades is verified to ensure efficient cutting of raw fibers without jamming, completing the core mechanical operability test for the final prototype.
• Integration: This entire assembly is dropped into the main machine chassis. One shaft extends through the transmission mount to connect with the main gearbox, making it the primary drive train.

Chassis Structural Base Fabrication

• Description & Function: For the final prototype base, Esteban Valladares prepared this functional structural part for additive manufacturing. It is a robust baseplate designed with integrated mounting points for the high-torque motor and the cutting chamber assembly. Crucial CAM settings are defined: ABS filament (black), 15% grid infill for structural integrity, and a 0.20mm layer height. The generated brim is visible, ensuring adequate adhesion for this large structural part.
• Integration: After successful fabrication and post-processing, this ABS baseplate becomes the foundation of the final machine, bolted directly to the central chassis and serving as the anchor for the motor assembly.

Power Drive and Chassis Assembly Main Chassis and Final Material (ABS)

• Description & Function: This CAD model, shown in wireframe by Esteban Valladares, defines the geometry for the final central chassis structure. It is designed to be a single, lightweight but robust part, suitable for additive manufacturing using ABS. It integrates robust mounts for the high-torque main motor and a stable platform for the shredding unit, validated for final machine operability.
• Integration: This central ABS chassis is the main structural skeleton. Once manufactured and finished, it is anchored to the ABS baseplate and supports the integrated gearbox/motor assembly and the complete cutting chamber housing.

Gearbox and Final Power Drive Train

• Description & Function: The high-torque main motor (visible here, right) is now physically integrated with the complete transmission gearbox. The custom 3Dprinted gears (from previous validation phases) are locked onto the shafts and fully enclosed within their robust polymer housing. This system performs a variable speed reduction to convert high RPM from the motor into the massive torque required for shredding tough fibers. This integration marks a critical milestone for Esteban's mechanical validation.
• Integration: This entire motor and gearbox unit is mounted to the central ABSchassis, aligning with the transmission mounts for direct coupling to the main hex shaft.

Final Prototype Chassis Assembly

• Description & Function: This image captures the integrated physical assembly of the final prototype chassis. The central ABS structural backbone (designed by Esteban) successfully supports the integrated motor/gearbox unit and the complete shredding chamber assembly. The mechanical components are interlinked and functionally verified. The open design allows for final inspection before electronic integration and enclosure.
• Integration: This functional chassis is now ready for the integration of the custom control PCB, motor drivers, and sensor arrays led by Jianfranco Bazan, merging the mechanical operability with the "Smart" capabilities.

Electronic Integration and Sensor Arrays

Custom PCB Shield Design (Altium)

• Description & Function: This Altium Designer layout defines the Electronic Heart of the Smart Shredder, designed by Jianfranco Bazan. It is a custom "Smart Shield" PCB that integrates the main microcontroller (eg, an ESP32 for IoT features), motor driver interfaces, and sensor inputs (for torque and fiber consistency). The robust power traces are visible, necessary for managing the high currents required by the main motor. This design provides automated control over the shredding process.
• Integration: This custom PCB is fabricated (eg, via FabLab PCB milling), populated with components, and permanently mounted to the central ABS chassis, acting as the centralized control unit.

PCB Milling Process (CAM Preparation)

• Description & Function: This FlatCAM interface shows the CAM preparation for the custom control PCB design. Jianfranco Bazan generated the final G-code files required for the FabLab's precision PCB milling machine (eg, a Roland Monofab). The software generates the isolation routing paths (the small channels that define the traces) and the drilling locations for through-hole components, ensuring accurate electronic fabrication.
• Integration: The isolation routing G-code is used to mill the actual copper PCB,which is then populated and integrated into the central chassis as the main control board.

Integrated Power Electronics and Control

• Description & Function: The custom control PCB is now fully populated, soldered, and integrated into the Smart Shredder central chassis. Jianfranco Bazan mounted the board using custom adapters. It is powered by robust connectors and features two high-current L298N motor drivers (red boards), configured in parallel for torque regulation of the main motor. This "Smart Shield" PCB controls the motor's automated sequences based on sensor feedback.
• Integration: This populated board is the central electronic hub. It connects to the motor power inputs, the sensor arrays, and the external power supply, managing the entire machine's operation.

Smart Fiber Processing: Cooking Unit and Sensor Feedback

• Description & Function: This block links the initial conceptual whiteboard sketch to the physical implementation of the fiber processing workflow. The diagram, tracked by the documentation team (Grace, Mario, and Rocio), defines the "Smart" workflow: the processed fiber from the main shredder is added to water and cooked with ash or bicarbonate. This image shows the final prototype being repurposed as the "cooking pot" for this specific fiber. The diagram highlights the location for the temperature sensor (crucial for automated regulation of the cooking cycle) and the feedback loop to the custom PCB designed by Jianfranco Bazan, closing the loop on a truly integrated, smart bio-material processing system. Cindy Crispin validated this workflow with the final fibers.
• Integration: This automated cooking unit is controlled directly by the custom PCB, using a custom temperature probe to regulate the heat source and a small stirrer/ blender motor, ensuring repeatable and efficient bio-material preparation.

16/04/2026

Machine Chassis and Enclosure Fabrication Preparation of Final Housing (ABS)

• Description & Function: This block showcases the advanced CAM preparation phase managed by Esteban Valladares and Carmen Gutierrez. The main chassis of the Smart Crusher, designed to house all mechanical and electronic components securely, is prepared for additive manufacturing. Specific settings are defined for a robust print: ABS filament (black), a 15% grid infill for structural integrity without excessive weight, and a 0.20mm layer height. The use of ABS ensures heat and chemical resistance, vital for the future cooking and processing stages. A brim is generated for adequate bed adhesion.
• Integration: After successful fabrication, this ABS chassis becomes the primary structural shell, bolted directly to the machine base and providing the necessary mounts for all integrated subsystems.

Variable Inlet Mechanism (Iris Aperture)

Iris Blades Assembly and Test

• Description & Function: This image captures a critical feasibility test for a specialized variable-inlet mechanism. Several custom iris blades, designed by Esteban and Carmen and laser cut from polymer, are intermeshed on a prototype baseplate. This mechanism operates like an optical iris, varying the internal diameter to regulate the amount of bio-fiber that can enter the shredding chamber. This component is crucial for the "Smart" aspect of the machine, allowing for automated throughput regulation based on material consistency, a concept verified by Cindy Crispin's material research.
• Integration: These intermeshed polymer blades are later permanently integrated into a custom-designed rotating ring assembly and mounted directly above the main fiber hopper inlet on the shredding unit.

Integrated Iris Assembly (Model)

• Description & Function: This 3D model view from Altium Designer displays the final, complex Iris mechanism fully assembled and integrated within the top hopper section. This intricate subassembly consists of dozens of custom blades (like those from the previous test), control rings, and actuators. It is designed by Esteban Valladares and Carmen Gutierrez to provide a variable aperture.

The view includes the specialized control rings and linkages that will be driven by a small servo or motor (controlled by Jianfranco's electronics) to adjust the opening dynamically.

• Integration: This entire multi-component Iris module is bolted directly to the fiber hopper inlet on the main shredder housing, creating the automated, variable-throughput inlet system.

Smart Fiber Processing and Process Monitoring (Diagram)

• Description & Function: This diagram, tracked by the documentation team (Grace, Mario, and Rocio), refines the "Smart" workflow (previously defined in Image_5.png and Image_16.png). It focuses specifically on the Fiber Cooking phase. The processed fiber is added to the "Final Prototype" (the cooking pot). The sketch highlights the crucial location for the temperature sensor (Tº) and the automated regulation of the cooking cycle. The diagram details the feedback loop to the custom PCB, where a temperature probe monitors the heat source to ensure repeatable and efficient bio-material preparation. Cindy Crispin validated this sequence for the chosen fibers.
• Integration: This automated cooking sequence is controlled directly by the custom PCB, using a custom temperature probe to regulate the heat source and a small stirrer/blender motor.

Electronic Integration and Control

Custom Controller Shield (Milling Data)

• Description & Function: This FlatCAM interface shows the CAM preparation for the custom controller PCB design, specifically the board that will drive the variable speed motor and sensors. Jianfranco Bazan generated the final G-code files required for the FabLab's precision PCB milling machine. The software generates the isolation routing paths (the channels defining the traces), drilling locations for through-hole components (like connectors), and the board profile cut. This CAM validation is crucial before actual manufacturing.
• Integration: The generated G-code is used to mill the custom PCB, which is then populated with components and integrated as the central control unit for the machine's operation.

Integrated Power and Variable Speed Control

• Description & Function: The custom control PCB is now fully populated, soldered, and integrated within the central machine chassis. Jianfranco Bazan designed this "Smart Controller" shield (Altium layout from previous blocks). The populated board is mounted and connected to a robust, high-current L298N motor driver (red board, right). This configuration allows the microcontroller (eg, ESP32, visible on the board) to manage the main motor's variable speed sequences, providing the necessary torque control based on sensor inputs and automated routines.
• Integration: This populated board is the machine's central electronic hub. It connects to the variable speed motor driver, the main power input, the temperature sensor array, and the servo actuator for the automated Iris mechanism, completing the integrated control system.

17/04/2026

Advanced Mechanical Integration & Power Train

1. CAM for Torque Transmission Components
   • Description & Function: This image shows the advanced CAM preparation phase managed by Esteban Valladares. The FlatCAM interface is being used to generate G-code for a complex transmission component. This part is designed by Esteban and Carmen to handle the massive torque required to shred tough fibers. FlatCAM generates the isolation routing and profile cut paths (blue lines), defining the high-tolerance features required for motor coupling and gear mesh, crucial for machine operability validation.
   • Integration: The generated G-code is used to mill or CNC-machine this heavy-duty

transmission part, which is then integrated directly between the main motor shaft and the shredding gearbox, completing the primary power drive train.

2. Fully Intermeshed Cutting Stacks
   • Description & Function: This image marks the completion of the core mechanical assembly. The two counter-rotating hex shafts (designed by Esteban and Carmen) are now fully populated with the interlocking blades and modular spacers. The entire matrix is locked within the high-grade polymer cutting chamber housing. The white precision bearing blocks are integrated, ensuring smooth and non- interfering rotation. This assembly is the primary processing unit, designed by Esteban to maximize machine operability and throughput.
   • Integration: This functional cutting unit is bolted directly to the central chassis and anchored to the transmission system (milled in Block 1), finalizing the mechanical core.

Chassis Assembly and System Enclosure

3. Main Chassis Structural Assembly (Metal Prototype)
   • Description & Function: This block showcases the integration of the main machine backbone. Esteban Valladares designed and assembled this robust metal chassis structure. It serves as the primary structural skeleton, providing rigid mounting points for the high-torque main motor and the intermeshed cutting unit assembly (from Block 2). This metal prototype maximizes rigidity, crucial for managing the intense mechanical forces generated during shredding.
   • Integration: The integrated motor/gearbox unit is bolted to this structure,

followed by the complete cutting chamber housing. Once mechanically complete, the final external enclosure panels (to be designed by Carmen) are attached.

4. System Interconnections and Prototype Management (Whiteboard)
   • Description & Function: This diagram, tracked by the documentation team (Grace, Mario, and Rocio), refines the systems architecture for the Final Prototype. It visualizes the transition from the shredding phase to the cooking phase (previously seen in Image_5.png and Image_16.png). The processed material ("Tronco del Platano") is added to the finalized "Prototype" (the cooking pot). The sketch highlights crucial locations for temperature monitoring (Tº) and feedback loops to Jianfranco Bazan's custom PCB for automated regulation of the bio-paper workflow. Cindy Crispin validated this sequence for repeatable output quality.
   • Integration: This system flow is controlled directly by the central PCB (Block 6), which uses sensors to manage the motorized sequences and temperature regulation during the cooking stage.

Electronic Integration and Automated Control

1. Custom Altium PCB Layout for Process Control
   • Description & Function: This Altium Designer layout defines the Electronic Heart of the Smart Shredder, designed by Jianfranco Bazan. It is a custom "Smart Controller Shield" PCB that integrates the main microcontroller (ESP32) with specialized circuits for high-torque motor control and sensor feedback. The layout features robust, high-current traces, dedicated interfaces for the L298N motor drivers, and input headers for the temperature and torque sensor arrays. This board provides the automated control required to regulate the shredding and cooking processes.
   • Integration: This custom PCB is fabricated and permanently mounted to the central metal chassis (Block 3). It is the centralized hub connecting all motors, sensors, and the external power supply, managing the entire machine's automated sequences.

APRIL 18

Final Electronic Integration & Control Logic

1. Embedded Programming and System Control Logic
   • Description & Function: This block marks the transition from hardware integration to functional control, led by Jianfranco Bazan. The Arduino IDE is being used to write and upload the primary control code to the machine's main microcontroller (the populated ESP32 shield from previous blocks). This firmware defines the automated sequences:
     1. Activating the high-torque shredding motor with variable speed.
     2. Monitoring temperature and torque sensors.
     3. Activating the Iris variable-inlet mechanism. The code uses specific
   libraries, such as ESP32Servo, and is programmed in C++.

Integration: The uploaded code is stored permanently in the ESP32's flash memory, making the custom PCB shield the central, smart control hub for the entire machine.

2. Power and Torque Monitoring Interface
   • Description & Function: This block highlights the development of the highpower sensor array, also designed by Jianfranco Bazan in Altium Designer. This Power/ Torque Monitoring PCB Shield is a dedicated interface for the main high torque motor and variable-speed drivers (eg, L298N). It features a robust screw-terminal connector (J2) and custom headers to connect directly to the main ESP32 controller. This design allows the microcontroller to monitor motor current consumption and calculate applied torque, providing real-time data to regulate the variable speed and adjust the automated Iris mechanism throughput.
   • Integration: This populated power shield is integrated between the main motor drivers and the final high-torque motor, connecting to the main control shield to provide dynamic torque feedback during shredding.

3. Verification of Final Metal Chassis and Torque Drive
   • Description & Function: This block focuses on validating the heavy-duty power transmission system, designed by Esteban Valladares and Carmen Gutierrez. The custom-designed, heavy-duty gear (milled or CNC machined from metal) is shown here in its final unpopulated prototype state. It features the custom internal hex-profile designed to couple with the intermeshed blade stacks and transmit massive torque from the high-torque main motor, crucial for machine operability under load.
   • Integration: This physical metal gear is integrated directly into the primary

transmission gearbox assembly meshing with the motor pinion to convert speed into shredding power.

4. Integration of Electronic Power and Variable Speed Drivers
   • Description & Function: This block showcases the integration of the electronic power drive system. The custom "Smart Controller Shield" PCB (designed in Image_35.png and populated in Image_34.png) is permanently mounted and connected within the central machine chassis. It features the integrated ESP32 microcontroller (visible on the shield) and two high-current L298N motor drivers (red boards, visible), configured in parallel to handle the variable speed regulation of the main high-torque motor. This integrated electronic system managed by Jianfranco Bazan is now ready for functional tests.
   • Integration: This fully populated electronic assembly is the system's brain and

heart, bolted to the central metal backbone. It is connected to the primary power input, the final torque sensor arrays (Block 3), and the main high-torque motor (validated in Block 5), completing the machine's functional integrated control system.

19/04/2026

Final Mechanical Assembly & Full System Integration

1. Integration of Dual Counter-Rotating Cutting Stacks

• Description & Function: This block represents the definitive integration of the shredding core, meticulously designed by Esteban Valladares and Carmen Gutierrez. The main high-grade polymer cutting chamber housing is now permanently populated with the two intermeshed counter-rotating hex shafts. These shafts are equipped with the 27 modular cutting blades (detailed in previous blocks) and locked in place. Esteban verified that the

Integrated precision bearing blocks (white components) are aligned with zero interference, ensuring smooth, non-binding mechanical operability, which is crucial for high-torque fiber shredding.

• Integration: This functional cutting unit assembly is bolted directly to the central metal chassis backbone. The main hex shaft extends through the housing to couple directly with the main high-torque motor and gearbox (Image_10.png), completing the machine's primary powertrain.

Learning Achieved

Through the group project, I learned how to develop a complete machine by integrating mechanical design, digital fabrication, electronics, and biomaterial processing into a single functional system. I understood the importance of teamwork, system integration, and validating real-world applications to transform organic waste into useful biomaterials such as bio-paper.

My individual contribution

Within the group project “Bio Crusher”, my contribution focused on the technical definition of the biomaterial transformation process and functional validation of the final product, ensuring that the mechanical design responds to a real application: the production of bio-paper.

Responsibilities:

• Research and selection of biomaterials (cassava, coconut, banana and pineapple) based on their processing feasibility
• Definition of the complete transformation flow (crushing → cooking → blending → pulping)

• Validation of the material's behavior in relation to the cutting system
• Experimental tests for obtaining bio-paper pulp
• Evaluation of system functionality under real-world conditions

My approach was not limited to the analysis of the material, but also to ensure consistency between the mechanical design and the final result, verifying that the machine produces a biomaterial that is actually usable within a production process.

Definition of the process

An integrated biomaterial transformation flow was established, oriented towards obtaining pulp for bio-paper, ensuring consistency between the physical properties of the material and the capabilities of the developed mechanical system.

Process flow:

Organic matter → Crushed → Cooked → Blended → Pulp

Stages of the process:

1. Collection and selection of organic fibers

Materials such as banana, pineapple, coconut, and cassava were identified, and their availability, fibrous strength, and processing feasibility were evaluated.

2. Mechanical crushing

The machine reduces the size of the fibers, facilitating their subsequent chemical and mechanical treatment.

3. Cooking with chemical agents (ash or bicarbonate)

A softening process was applied to break structural bonds in the fiber and improve its processability.

4. Fiber smoothie

The crushed material is homogenized to obtain a uniform mixture.

5. Obtaining pulp

A mass suitable for the manufacture of bio-paper is obtained, validating the objective of the system.

Technical approach to the contribution

My contribution consisted of defining and validating this flow as a system, ensuring that each stage is aligned with:

• The actual capabilities of the crushing machine
• The physical properties of biomaterials
• The ultimate goal of bio-paper production

This allowed the mechanical design not to be isolated, but part of afunctional and verifiable production process.

Biomaterials flow diagram

Relationship with mechanical design

The prior analysis of the biomaterials made it possible to establish functional requirements for the mechanical design of the machine, ensuring compatibility between the crushing system and the physical properties of the organic fibers.

Defined parameters:

• Geometry and type of blades required for fiber cutting
• Mechanical resistance of the material to be processed
• Torque required to prevent loss of force during crushing
• Expected particle size for subsequent cooking and blending stages

Validations performed:

• The blades allow for the efficient fragmentation of organic fibers.
• The material flows properly without creating critical blockages
• The resulting size facilitates subsequent processing.
• There is consistency between mechanical capacity and biomaterial requirements

Analysis results

The study confirmed that the developed mechanical design adequately responds to the proposed application, validating that the machine not only operates correctly, but it fulfills a specific function within the bio-paper production process.

The relationship between material, mechanism, and final result was fundamental to ensuring the system's functionality.

Validation of the crushed material and mechanical system

Material validation

Experimental tests were carried out to verify that the mechanical system fulfills its purpose within the bio-paper production process, evaluating the transformation of the material at each stage.

Evaluation criteria:

• Particle size reduction
• Softening capacity during cooking
• Homogeneity of the material after liquefaction
• Final consistency of the pulp

Results obtained:

• Effective reduction of fiber size, facilitating its processing
• The crushed material responds well to cooking (softening)
• A homogeneous mixture is obtained after blending.
• The pulp has a consistency suitable for the formation of bio-paper

Technical analysis

The results demonstrate that the shredding machine fulfills a critical function in the system, as it transforms a rigid fibrous material into a processable raw material.

Without this stage, the pulp production process would not be viable.

Furthermore, it is validated that:

• There is continuity between stages (crushing → cooking → blending)
• The material retains properties suitable for its final transformation.
• The system responds correctly to different types of organic fiber

Comparison of fiber before and after the process

Problems and solutions

Problem 1: Fiber too rigid

Solution: Material pretreatment (cutting or hydration)

Problem 2: Jam in the blade system

Solution: Evaluation of spacing and material type

Improvement proposal

Based on the tests performed, opportunities were identified to optimize system performance through the incorporation of automation and intelligent control.

Proposed improvements:

Integration of humidity sensors

It would allow us to evaluate the state of the biomaterial during the process, adjusting cooking and liquefying conditions to obtain a more uniform pulp.

• Automatic engine control according to load (torque)

By monitoring current or mechanical stress, the system could regulate the motor speed, preventing blockages and reducing component wear.

• Regulation of material intake (iris-type mechanism)

It would control the amount of fiber entering the system, maintaining a constant flow and preventing overloading in the shredding chamber.

Impact on the system

Implementing these improvements would allow:

• Optimize energy consumption
• Reduce mechanical failures due to overload
• Improve the quality and uniformity of the pulp
• Increase the efficiency of the production process
• Evolving from a mechanical system to a semi-automated system

Strategic approach

These improvements transform the machine from a functional prototype into ascalable solution, with potential application in:

• Sustainable production of biomaterials
• Circular economy ventures
• Low-cost semi-industrial processes

The next logical step would be to integrate these improvements into a version 2.0 of the system.

Integration with the general system

The development of the project allowed for the coherent integration of multiple subsystems, achieving a functional system oriented towards the production of biomaterials.

Integrated components:

• Mechanical system

Responsible for shredding fibers using the set of blades and torque transmission.

• Electronic system

It includes motor control, drivers, and the possibility of integrating sensors for process monitoring.

• Biomaterial process

Define the transformation of organic matter from its initial state to obtaining pulp.

System interaction

The operation is based on a continuous flow logic:

Organic matter → Crushing → Processing → Pulp

Where each subsystem fulfills a specific role and is dependent on the previous one.

Integration analysis

It is evident that the project is not limited to an isolated component, but rather constitutes abasic mechatronic systemin which:

• The mechanical system performs the physical transformation
• The electronic system allows for control and future automation.
• The biomaterial process validates the real-world application

The correct interaction between these elements guarantees the functionality of the entire system.

Project value

This integration demonstrates the ability to:

Design complete solutions (not just parts)

• Relate hardware to real-world application
• Develop systems with scalability potential

The project transcends the prototype and positions itself as a basis for sustainable production systems.

Final result – HERO SHOT

The developed system demonstrates the functional operation of the crushing machine within the biomaterials production process.

System capabilities:

• Processing of organic fibers under real conditions
• Effective reduction of material size
• Generation of raw material suitable for bio-paper
• Integration of mechanical, electronic and application systems

Evidence of operation

The system shows:

• Stable mechanical operation (without critical blockages)
• Continuous flow of material during the process
• Coherence between input (fiber) and output (shredded material)
• Proper preparation of the material for subsequent stages

Value of the result

The prototype reaches a functional level that validates:

• The feasibility of the mechanical design
• The correct selection of materials and components
• The real-world application in biomaterials processes

It is not just a machine: it is a system applied to a specific need (sustainable production of bio-paper).

Problems and solutions

Problem 1: The pieces did not fit together correctly

Solution:

The measurements and tolerances in the 3D design were adjusted before the parts were remanufactured.

Problem 2: The structure was unstable

Solution:

The design was reinforced by adding supports and improving the distribution of the pieces.

Learning achieved

During this week's development, key competencies in mechanical design applied to real systems were consolidated.

Technical learning:

• Understanding the relationship betweenmaterial properties and mechanical designespecially in the behavior of organic fibers under shear and compression stresses.
• Application ofengineering criteriafor the selection of components, considering resistance, torque and system functionality.

Validation of an actual production process, verifying that the system's output (shredded fiber) meets the requirements for obtaining biomaterial.

• Integration ofmechanical design with a sustainable approachaligning the technological solution with the use of organic waste.

Systems learning

• Understanding that a machine is not an isolated element, but part of a complete production system.

• Ability to analyze the interaction betweeninput (raw material), process (crushing) and output (pulp).

Collaborative learning

• Teamwork under an interdisciplinary approach (design, electronics, materials and documentation).

Coordination of roles to achieve a functional result in a complex system.

Key insight

Mechanical design is not just about building structures, but about to solve a real need considering material, process and final result.

📋 Check-off List

1. Did you document the machine's construction process on the group's page?

Yes. The entire process of building the machine was documented, including assembly, manufacturing, configuration, and testing performed by the team.

2. Did you document your individual contribution to this project on your own website?

Yes. My individual participation within the group project was explained, detailing the tasks and contributions made during the development of the machine.

3. Did you link the group page from your individual page and vice versa?

Yes. A link was added between the group page and each member's individual pages to keep the documentation connected.

4. Did you show how your team planned, assigned tasks, and executed the project?

Yes. The team organization, task distribution, coordination, and execution of the activities necessary to build the machine were documented.

5. Did they describe the problems and how they solved them as a team?

Yes. The problems encountered during the assembly and operation of the machine were explained, along with the solutions implemented by the team.

6. Were any potential improvements to the project listed?

Yes. Improvements were proposed related to stability, accuracy, automation, and overall machine optimization.

7. Did they include the design files?

Yes. The design files and documentation necessary for the manufacturing and assembly of the project were incorporated.

8. Did they present the machine globally and/or include video and slides?

Yes. The machine was presented in general terms, including visual evidence of the project, in addition to the required MP4 video and PNG slide.

❓ Frequently Asked Questions

1. Do we need to design one or more new boards for this task?

Answer:
No. In my project, it wasn't necessary to design new electronic boards. I used existing systems and components developed in previous weeks, integrated within the Bio-Crusher system. This week's main focus was on the machine's mechanical design, its assembly, system automation, and the functional integration of the various subsystems (mechanical, electronic, and control), not on manufacturing new PCBs.

2. I am the only student in the lab, can I complete the assignment by building the machine on my own?

Answer:
No. This activity was developed as a completely collaborative effort. In my case, the Bio-Crusher project was built as a team, where each member assumed specific responsibilities within the design, manufacturing, assembly, testing, and documentation. The machine could not have been functionally developed without coordination among the group, since each part of the system depended on the work of the others.

3. What is the recommended size of the equipment?

Answer:
The recommended team size is between three and five members. In our case, we worked as a multidisciplinary team where each person contributed their expertise: mechanical design, digital fabrication (CNC, 3D printing, and laser cutting), electronics, programming, materials testing, and documentation. This structure allowed us to make organized progress in the development of the Smart Shredder.

4. Can we use commercial software?

Answer:
Yes. In developing the project, we used commercial software and industry-standard tools, such as CAD software for mechanical modeling, slicing software for 3D printing, CNC and laser cutting tools, and programming environments like the Arduino IDE for system control. These tools were essential for developing and validating the prototype without limiting the design or functionality.

5. Is it necessary to document how machine building tasks were assigned to group members?

Answer:
Yes. In our project documentation, the clear division of roles within the team is outlined. Each member had defined responsibilities: mechanical design of the structure, development and manufacturing of parts, integration of electronic components, programming of the control system, testing with biomaterials, and technical documentation. This division of labor allowed us to build the Bio-Crusher in an organized and efficient manner.

6. What would happen if the machine wasn't ready and my group couldn't perform?

Answer:
If the machine is not completely finished, it is necessary to demonstrate the development process. In our case, we documented the entire development of the Bio-Crusher, from the initial concept to manufacturing, assembly, and functional testing. Furthermore, we included visual and video evidence of the system's partial or complete operation. This allows us to demonstrate the work done even if the system is not 100% finished.