Master Chef Scabbard

CAD model of the “Master Chef Scabbard”

Design.

While my initial brainstorming sessions focused on developing gifts for others, I eventually decided to design a gift for myself. Since I gravitated toward ideas related to lighting and video games, I eventually settled on creating a Legend of Zelda themed lamp, which would involve Link’s glowing master sword. However, after experiencing several hardware issues during week 8 of my mechatronics course, I decided that I would be much happier creating something that did not involve circuitry.

After more lateral thinking, I finally generated an idea that really excited me: a sheath for a chef’s knife based on the master sword sheath from Legend of Zelda: Twilight Princess. My goal for the “master chef scabbard” was to spark joy in my daily life by transforming myself into a hero every time I chopped celery and diced onions. I lasercut a duron model of my vision to finalize sizing and detailing decisions before proceeding with CAD and CAM design.

Manufacturing.

STOCK
  • ⅜″ x 3″ x 3″ Brass
  • ¼” x5.5” x 3’ Walnut board
TOOLS
  • 3″ Shell Mill
  • ⅛” and ¼” Flat End Mill
  • ⅛” Ball End Mill
  • ¼” Drill
(Intended) PROCESS
CNC machining process: Brass
  1.  Square brass stock using a manual mill
  2. On Haas CNC, perform facing operation to mill stock to required thickness
  3. Perform adaptive clearing operation to reveal triangles, down to 0.1″ above model bottom
  4. Scallop all chamfers
  5. Perform another adaptive clearing operation, leaving a thin web of 0.005″
  6. Separate each triangle using band saw and files
  7. Finish parts using sand paper and polish

 

CNC machining process: Wood
  1.  Plane walnut board and saw into two 16″ pieces
  2. On ShopBot, perform pocket clearing operation for knife slot
  3. Drill holes for alignment dowels
  4. Part flip!
  5. Perform adaptive clearing operation to rough out detailing, down to 0.1″ above model bottom
  6. Scallop all curves and fillets
  7. Perform another adaptive clearing operation to remove excess material
  8. Separate part from tabs using band saw
  9. Repeat steps 2-8 for other half of the sheath
  10. Use wood glue and dowels to fasten both halves of the sheath together
  11. Finish wooden sheath using sand paper and mineral oil
  12. Attach brass triangles to sheath using epoxy

Learning.

Although the COVID-19 outbreak restricted our use of the CNC during week 10, I was able to think laterally, refine my CAD models, and dedicate time toward grasping CAM software. Overall, I had a great time learning about machining, tooling, workholding, lateral thinking, and communication.

If I could redo this project, I would explore alternative ways of fastening my wooden and brass parts. I would also redesign the sheath such that only one half had a knife-shaped cut-out while the other half was completely flat. Then, my project would only require a single part flip rather than two part flips, which would reduce my risk of misalignment. On the bright side, since the PRL won’t reopen for another few weeks, I have plenty of time to continue laterally thinking and improving my CAD and CAM files before I actually manufacture this project. Thank you to Craig and Taylore for their guidance throughout this quarter!

Exploded view of entire assembly

Leave a Reply

Your email address will not be published. Required fields are marked *