week 12 Mechanical design, machine design
Objectives
Rotary Tool Table
Project Ideation and Inspiration
We conducted several intensive brainstorming sessions before finalizing our project concept: the Smart Tool Table. The idea was inspired by the traditional Chinese rotating table (Lazy Susan), which is commonly used for easy access to shared items.
Source.
Concept Overview
The Smart Tool Table is designed as a circular rotating workstation with multiple compartments to organize and store tools efficiently. Each compartment is dedicated to specific tools or components, allowing quick identification and access.
Source
Functionality and Innovation
The key feature of this system is its voice-controlled automation using Alexa. When a user calls out the name of a tool or gives a command, the table automatically rotates to bring the required compartment within reach. This reduces manual effort and improves workflow efficiency.
Objective
- Improve accessibility and organization of tools
- Reduce time spent searching for components
- Introduce automation into a traditional tool storage system
- Enhance user convenience through voice interaction
Testing Jig for Screw Hole Alignment, Heat Insert Installation, and Bearing Fitment
Purpose of Testing
The purpose of the screw hole test is to determine the appropriate tolerances required for proper screw fitting, heat-threaded insert installation, and bearing press-fit. This ensures accurate assembly, secure fastening, and optimal mechanical performance of all components.
This jig is designed in Autodesk Fusion to check press-fit accuracy and alignment of components.
Components Tested
- Direct screw inserts: M3, M4, M5
- Heat-set inserts (soldering method)
- Bearings:
- 608ZZ (inner & outer fit)
- 625ZZ (inner fit)
Issues Faced
1. Bearing Fit Issue (Design Error)
- 608ZZ outer diameter slot was too tight in the initial design.
- Issue identified only after 3D printing.
- Insufficient internal clearance for bearings.
- Solution: Reprinted jig with corrected tolerances — fit is now proper.
2. Heat Insert Availability & Size Mismatch
- Only M4 screws and M4 heat inserts were available in the lab.
- M3 and M5 inserts were not available for testing.
- M4 insert dimensions did not match the designed hole size.
- M3 design worked correctly based on standard sizing.
Final Corrected Dimensions
- M3 heat insert hole: 5.20 mm
- M4 heat insert hole: 5.00 mm
- 608ZZ Bearing:
- Outer diameter fit: 22.10 mm
- Inner diameter fit: 8.20 mm
- 625ZZ Bearing:
- Inner diameter fit: 5.10 mm
Key Learnings
- Always verify component dimensions physically before finalizing CAD design.
- Heat-set inserts vary slightly by manufacturer.
- Small tolerance changes (~0.1 mm) significantly affect press-fit performance.
3D Printing Preparation
The design files were converted into STL format and imported into Bambu Studio for slicing.
In Bambu Studio, the model was prepared for printing by setting the layer height to 0.28 mm and adjusting the infill density to 15%. These settings provided a balance between print speed, strength, and material usage.
3D Printing Process
The test model was printed using the Bambu Lab A1 3D printer.
After slicing the model in Bambu Studio, the build plate was prepared and the "Print Plate" option was selected.
The file was then sent to the printer using the "Send File" option. Once the file was successfully transferred, the printer received the job and began printing the model.
Heat Insert Installation
The model was printed using PLA material, with a nozzle temperature set to 210 °C, ensuring good layer adhesion and print quality.
To install the heat-set inserts, a soldering iron with an appropriate tip was used. The correct end tool was selected based on the insert size to ensure accurate alignment and proper heat transfer.
The insert was placed into the designed hole, and controlled heat was applied. This allowed the insert to melt into the plastic and seat firmly without deforming the surrounding material.
Final Jig Output
Group Assignment Jig
Final Jig Assembly
My Contribution
During Week 12 – Machine Making, we worked as a group of five to design and build a machine. My role focused on both documentation and hands-on fabrication support throughout the project.
Responsibilities
- Developed and maintained complete group documentation.
- Captured photos and videos of each stage of the process.
- Prepared and organized manufacturing materials.
- Assisted in CNC machining operations.
- Performed 3D printing of required components.
- Handled post-processing including cleaning, finishing, and fitting adjustments.
- Participated in the final assembly of the machine.
Reflection
This role allowed me to actively contribute to both the technical and documentation aspects of the project. I gained hands-on experience in digital fabrication processes while ensuring that the workflow was clearly recorded and presented. This improved my understanding of coordination between design, manufacturing, and assembly in a team-based environment.
Conclusion
We successfully completed our rotary tool table as a team. Each member contributed effectively, ensuring that all stages—from design to fabrication and assembly—were completed smoothly.
The system was successfully integrated with Alexa , allowing voice-based control of the table.
Throughout this project, we learned valuable lessons in digital fabrication, including CNC machining, 3D printing, tolerance management, and assembly techniques. This experience also improved our teamwork, problem-solving, and practical implementation skills.
Hero Shot
References
- ChatGPT – https://chat.openai.com/
- Fab Academy 2025 – https://fabacademy.org/
- Ancy Roshan – Week 12 Documentation – View Page
- Autodesk Fusion – Fusion 360
- Bambu Studio – Bambu Studio
- ShopBot CNC – ShopBot
- Laser Cutting – Speedy 400 – Speedy 400