Week 07 – Computer-Controlled Machining
Modular Hexagonal Cell – TPS-Based Assembly Station
Group Assignment – Lab Characterization and Safety Training
The group assignment for this week was developed at START LABS, located at the Universidad Politécnica Salesiana. The work was carried out collaboratively with the team members Jenny Rojas, Rodrigo Guamán, and Diego Zhindón, under the guidance of Roberto Gallo from ZOI Lab.
Lab Safety Training
As a first step, the team completed the laboratory safety training. This included understanding the correct use of digital fabrication equipment, identifying potential risks, and applying preventive measures to ensure safe operation.
- Proper use of Personal Protective Equipment (PPE)
- Machine-specific safety protocols
- Emergency procedures and risk awareness
- Safe material handling practices
Laser Cutter Characterization
The group conducted a detailed characterization of the laser cutter to understand its behavior and optimize cutting parameters. This process is essential to achieve precision and repeatability in digital fabrication.
- Focus: Adjustment of the focal distance to ensure optimal cutting precision
- Power: Evaluation of laser intensity for different materials
- Speed: Determination of cutting speed to balance quality and efficiency
- Rate: Calibration of pulse frequency for engraving and cutting
- Kerf: Measurement of material removed by the laser beam
- Joint Clearance: Definition of tolerances for press-fit assemblies
- Joint Types: Testing of different press-fit geometries and configurations
Multiple test cuts were performed using different parameter combinations, allowing the team to identify optimal settings for the materials used in the lab.
Documentation and Reflection
All the results, tests, and observations were documented on the group work page, including images, parameter tables, and conclusions.
Additionally, each team member reflected individually on their personal page, analyzing the knowledge acquired during the process. This included understanding machine behavior, improving parameter selection, and recognizing the importance of calibration in digital fabrication workflows.
This collaborative experience reinforced both technical and teamwork skills, emphasizing the importance of experimentation, documentation, and continuous learning within the Fab Academy methodology.
CNC Machine Characterization and Safety Requirements
Machine Characterization
| Parameter | Description |
|---|---|
| Machine Type | Flatbed CNC Router |
| Working Materials | Wood (plywood, MDF), plastics, composite materials |
| Working Area | Approximately 1200 x 2400 mm (4x8 ft format) |
| Cutting System | Rotary milling tool (end mill) |
| Axes | 3 axes (X, Y, Z) |
| Precision | ±0.1 mm depending on calibration |
| Spindle Speed | 12,000 – 24,000 RPM (variable) |
| Tool Type | Flat end mill, ball nose, others |
| Fixation System | Vacuum bed or mechanical clamps |
| Software | Aspire / VCarve / CAM software |
| Input Formats | DXF, SVG, G-code |
| Dust Extraction | Integrated dust collection system |
| Operation Type | 2D, 2.5D cutting and engraving |
| Power Supply | Industrial electric power |
Safety Requirements
Personal Protective Equipment (PPE)
- Safety glasses
- Hearing protection (earplugs or earmuffs)
- Dust mask or respirator
- Safety footwear
- No loose clothing, hair tied back
Before Operating
- Check tool installation
- Ensure material is firmly secured
- Set machine origin (X, Y, Z)
- Load correct G-code file
- Perform dry run simulation
- Verify dust extraction system
During Operation
- Do not place hands near cutting area
- Maintain safe distance
- Monitor the process continuously
- Watch for abnormal vibrations or noise
Emergency Measures
- Know the location of the emergency stop button
- Stop the machine immediately if tool breaks
- Stop if material becomes loose
- Stop if smoke or overheating occurs
After Operation
- Wait until machine fully stops
- Remove parts carefully
- Clean working area
- Inspect tool condition