Computer Controlled Machining

Learning Objectives

Assignments

Group Assignment

This week's group assignment provided valuable hands-on experience in CNC machining safety, machine operations, and precision testing. We began with comprehensive safety training, where we learned best practices for working with CNC routers and power tools. The importance of personal protective equipment (PPE), including goggles, masks, and hearing protection, was emphasized to ensure a safe working environment. Understanding these precautions is essential for minimizing risks and operating CNC machines efficiently.

Group Assignment

Beyond safety, we explored the ShopBot PRSalpha 96 CNC router, gaining insights into its functionality, controls, and toolpath execution. Learning about speeds, feeds, and material selection helped us understand how different factors influence machining quality. By working with our CNC router, we developed a deeper appreciation for machine accuracy, proper fixturing techniques, and the importance of setup precision in achieving successful cuts.

To apply our knowledge, we designed and tested a jig for runout , pocketing, dogbones and fit assessment, allowing us to evaluate the machine's accuracy and alignment. This hands-on approach reinforced key concepts of precision machining and troubleshooting. Overall, this assignment strengthened our understanding of CNC technology, machine calibration, and safe operational procedures, preparing us for more complex CNC fabrication projects in the future.

Individual Assignments

Design, Machine and Assembly something big

For my individual assignment, I decided to make a stand/media cabinet that could store books and records while also showcasing my final project—an NFC-based Spotify record player. I started by looking for inspiration on Pinterest, exploring different record player stands and media cabinets that could house a record player, speakers, books, and accessories. My goal was to design something that would not only be functional but also aesthetically pleasing and suited for my final project setup.

Design Process

Research & Inspiration

Before starting the design, I looked at various media cabinet designs online, particularly on Pinterest. I focused on cabinets that could efficiently store vinyl records, books, and speakers while having a dedicated space for the NFC Spotify record player. I took inspiration from minimalist designs that emphasized clean lines and modularity.

Parametric Modeling in Fusion 360

Once I had a clear vision, I started designing the cabinet in Fusion 360. Since I wanted flexibility in the dimensions, I set up a parametric model, defining key parameters such as height, length, width, and material thickness. This ensured that if I needed to make modifications, I could do so without manually adjusting each component.

Before I started designing, I watched some youtube tutorials for woodworking and design with Fusion 360 for wood working. The below youtube video was helpful for designing my media cabinet. The tutorial goes through building a bookshelf in Fusion 360. I wanted something similar for my assignment.

The below video shows how to add cabinets parametrically, this was also very helpful

I tried to sketch the design first before jumping into the Fusion 360 CAD Design. I went through a lot iterations of the design. The design had to be aesthetcially complementing the

After defining the parameters, I applied constraints to ensure all parts of the cabinet were properly aligned and structurally stable. I designed the shelves and compartments to fit my intended use, making sure the spacing accommodated vinyl records, books, and audio equipment. I also planned the joint types to make assembly easier.

Computer Aided Manufacturing

After finalizing the design, I exported the components as DXF files for CNC machining. I used the ShopBot CNC router to cut the parts from 18mm plywood. The machine was set up with a 1/4" end mill bit, and I adjusted the feed rate and spindle speed based on the material and bit specifications.

Learnings

I familarised with the Electronic Components, Circuits and EDA which will be useful for my further assignments and projects. The design of the two PCB boards helped me to familarise with the KiCad Software and the symbols, footprints and 3D Cad files.

I would love to explore more about better placement of components,

Design Files

You can download my design files from below

• Demo Board using Attiny 412

  Download ZIP

• Development Board using XIAO ESP32C6

  Download ZIP
  • Schematic
  • PCB
  • KiCad Project

• Trace File