Final Project Proposal Revision

Problems with Concept 1:

I had initially planned to build a mask projection SLA machine for my final project. It would have utilized thin layers of soldermask selectively illuminated by UV light to create a 3D part. Upon further research and testing, I determined that this approach was not feasible with the resources that I have available.

In particular, I found that standard LCDs do not pass light of ultraviolet wavelengths. Why this is true, I cannot say for sure, but I hypothesize that it has something to do with the shorter UV wavelengths being blocked (or not twisted in polarization properly) by the twisted nematic liquid crystal. There are LCDs on the market that are designed to pass UV light, but these are much too expensive and not within the scope or purpose of this class.

CNC RP platform - specifications:

Instead, as I missed out on the machine building sessions last week, I have decided to build a general 3-axis CNC platform. It will be made primarily from 2D parts cut on the waterjet. It will utilize T-nuts extensively. It will also have a manual milling mode (hopefully with a digital readout). It will incorporate a removable vise. It will be able to write with a pen, cut PCBs, mill many materials, and extrude viscous liquids. It will be heavily influenced by the Y-stage table, X,Z-stage head design of David Carr's Mantis, Jonathan Ward's MTM-AZ, and Natan Linder's MTM-LJ.

Components and Subsystems:

  • Stepper motors and leadscrews (X, Y, Z)
  • Structure (Waterjet Al, T-nuts)
  • Manual features (cranks, readout)
  • Spindle (motor, bearings, tool head)
  • Control system (EMC software, motor drivers)

  • Schedule:

    Week 1: Design prototype
    Week 2: Cut prototype, purchase parts
    Week 3: Assemble prototype
    Week 4: Make PCBs, install EMC distro, test prototype
    Week 5: Redesign
    Week 6: Recut
    Week 7: Reassemble
    Week 8: Test, debug, and fix


    ~$150 for steppers, motor, precision shafts, leadscrews, sleeve bearings, PCB boards, aluminum sheet.