Drinking Sunshine

Design Process

I started my final project thinking of things that would improve my life. My first idea, was to make something related to organization, because I am a messy person. I spend days doing lateral thinking, searching for organization tools, talking to people, and that led me to… nothing. All my ideas were either better suited for other machines, not CNC, or things I was not excited about making. I realized I am not organized because organization does not excite me, and I decided to change my project.

Then, I looked for problems I currently have, and, since it was the end of the quarter and my caffeinated tea consumption had increased, I looked closer into the action. I drink mate, and the classic way of doing so involves using a specific type of straw filter, a bombilla. My straw was rusting and it often burned my lips, so I decided to make a new one, or something to help me drink mate more comfortably.

(My current Bombilla)

First, I looked into problems I faced with my bombilla, like how hard it was to clean or how I always burned my lips, and possible solutions. Then I decided which problems I wanted to solve, and went on to drawing. I drew lids, animal-shaped bombillas, earth cross sections, and suns. I chose the latter, because I often say that I get my energy from the sun, so I thought it was a nice pun. At this point, I also decided to use acrylic, because it was a clear material that would allow me to see the tea going up, and would avoid my lips getting burnt.

  

Many sun designs later, I arrived to the two I prototyped. I tested not only the shapes, but also how the two head parts would connect to each other and the straw. I ended up with tabs for each of the parts to fit, and a slight taper on the tube connecting the head to the straw.

Materials & Tools

  • 1/2″ x 3″ x 3″ Clear Acrylic Block
  • 3″ Shell Mill
  • 1/2″ Flat End Mill
  • 1/4″ Flat End Mill
  • 1/8″ Flat End Mill
  • 1/16″ Flat End Mill
  • 0.04″ Center Drill
  • #51 Drill
  • 1/8″ Ball End Mill

Machining

I had two parts to machine, each with a quick part flip. I thought about the best operation sequence so that the tools would not create too much stress on my part, especially considering that I had a few drilling operations. But I did not consider using supports to ensure my part would continue fixed throughout the operations. Plastic did not withstand with only the vises and parallels, even though I kept a not-so-thin layer for the most part of the machining. The result is that my part slipped.

I had a plan for my following session, where I intended to use a block underneath my part, with double sided tape. That way my part would be secured by the vise, the block underneath it, and the tape. However, the PRL closed before I could machine it.

An Unexpected Journey

Design and Inspiration

This project brought me back to my childhood. I was an avid reader and my favorite author was Tolkien. I was fascinated by the world of hobbits, dwarves, elves, mages, and humans, and how you never knew what was going to happen – problems and their resolutions were always unexpected.

The process of making my bottle opener was not different. I started with some classic ideas of objects from the Middle Earth, until I was challenged to think of openers that the characters would have. From there, I was drawn to medieval, viking, and celtic aesthetic. I wanted to include natural elements, and I chose to do something elvish – light, with clear lines, and with organic shapes. This led to my round of prototypes:

Although I learned a lot from them, I also learned from Craig that I would not be able to manufacture them in the CNC. I went back to ideation, already knowing I wanted to use the elvish aesthetic, and ended up tapping into some abstract concepts I cherished in the book: friendship and surprise. After more ideation and a good amount of time on CAD, I arrived to my second and third rounds of prototyping. This led to my final design with two complement parts that opened bottles in a non-obvious position.

Manufacturing and Lessons

Then came the most unexpected part of the process for me. CAM was hard to do and I often ran into problems of the same selection yielding different results, like showing as if the tool path was inside of my part. Past that, I arrived on Saturday afternoon for machining my part, but I was not able to do it because I broke the tool probe. This was very stressful, but taught me to never forget the CNC guide at home because having it on your phone you can’t see the whole page, and to always ask a CA for help if you are unsure about something.

I returned on Monday and more unexpected problems followed. I had to re-do my CAM the night before and put the origin in the wrong place, which took me a while to figure out, and I was so nervous about having broke the probe on the weekend that I questioned everything. With the time left, I was only able to face my part, but that was enough to give me more confidence on the next day.

On Tuesday, now comfortable with the machine, I set up and ran my program. Something partially unexpected that happened was a tool breaking. Craig had already warned me that this could happen because of the length/diameter ratio of the tool, but I needed that size to continue. I lowered the surface speed for the next cut with a CA’s approval, and I had a good result.

Materials

Tools:

  • 3″ Shell Mill
  • 1/4″ End Mill
  • 1/8″ End Mill
  • 1/8″ Ball End Mill

Material:

7.3″x4.6″x1″ – Aluminum bar

Takeaways

Do lateral thinking early on. It took me a while to sit down and do it, and that cost me a lot of time and created a lot of stress when prototypes went wrong.

I learned to approach the machine with more confidence, and always refer back to your notes and/or a CA. I also realized much later that I could’ve used a much smaller stock piece, so for the future I will size appropriately my part before trying to acquire my material.