MECH200 Screwdriver Project

Lessons Learned

Tips for upcoming students:

  • In addition to time management (the constant companion), there were several other lessons learned from this project.

  • Knurling is not the only handle option, talk to your GTA and experiment if you are interested

  • Following the print is essential to getting a good grade

    • Even though my project is visually correct and aesthetically pleasing, all necessary tolerances were out of spec, down to the chamfers

    • This was due partly to hubris, and mostly to lack of time. I was so pressed for time that grinding to a functional shape took priority, with my grade and function suffering

  • Pay close attention to the heat treatment, my flat blade screwdriver has a stress fracture, meaning it has now become a very poor paperweight!

  • Bead blasting - it’s your friend, and your biggest foe

    • The surface finish produced is even, beautiful, and consistent

    • It loves to pick up scratches and mars if you so much as think about it too hard

  • DON’T BE AFRAID TO ASK QUESTIONS

Ideas to improve efficiency, and reduce cost to industrial process levels

  • Bulk material purchases: Can save 10% or more on raw material cost

  • Automated grinding and finishing process: This is perhaps the biggest potential time saver. Using jigs and automated processes, a single screwdriver can be accurately ground to tolerance within a matter of seconds or minutes, not hours

  • Automated finishing: Bead blasting on a bulk scale can be completed in a matter of a few seconds, opposed to the several minutes of a by-hand process

Cost of 10,000 unit process - EMEC vs. Industrial

The total cost to produce 10,000 units in the industrial process is $ 78,650

The total cost to produce 10,000 units with the EMEC process is over two million dollars! ( $ 2,010,200 )

Similarly to the clock project, the manufacture time will vary considerably. In an industrial process, it’s possible to cast, forge, grind, heat-treat and finish an entire screwdriver within approximately 10 - 15 minutes. This allows for all 10,000 units to be produced in less than a year.

The EMEC production process would require nearly 4 years of full shift work to complete all 10,000 units.

Cost comparison for a single EMEC-process unit vs.

Industrial 10,000 unit process