Clock Project

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This clock project represents the culmination of advanced machining and finishing techniques developed over the course using the equipment in the Engineering Manufacturing Education Center (EMEC). Aluminum, brass, and acrylic were used to showcase diverse manufacturing capabilities and material handling. Key processes included CNC milling, manual lathe turning, surface grinding, and detailed hand finishing. Emphasis was placed on tight tolerances, surface aesthetics, and functional assembly. The final piece reflects not only technical precision but also intentional design, demonstrating proficiency in multi-process fabrication and creative finishing techniques.

I thoroughly enjoyed this project because it allowed me to blend two facets of my personality: a love for engineering precision and creativity with personal meaning. I poured a lot of care into the processes, balancing the precision of the lathe and mill with fine hand sanding, along with a clock face finish that commemorates the completion of a personal project this semester. I proudly earned a 96%, a score that significantly exceeded the class mean (78.25%), median (83%), and upper quartile value (92.5%).

Lessons Learned

The clock project was the most significant assignment of the course, accounting for 35% of the overall lab grade. Because of its weight and complexity, careful planning and time management were essential to my success. One of the most important lessons I learned was the value of spreading out the workload across the project schedule. Starting early gave me the flexibility to adapt my machining schedule around unexpected obstacles, such as machine maintenance or high demand for lab equipment, without falling behind.

Good time management also gave me the opportunity to go beyond the basic requirements. With extra time available at the end of the project, I was able to polish the base, pen holder, and pencil holder to mirror finishes. This additional effort not only elevated the final presentation but also earned me extra credit. It reinforced the value of pacing the work to leave time for finishing details that can distinguish a good project from a great one.

Equally important was learning to leverage available resources. I made it a point to regularly ask questions and seek feedback from the lab GTAs and TAs. Their guidance helped me avoid common mistakes and ensured that I followed proper procedures when machining each component. In a project where precision matters and machine time is limited, proactive communication and smart scheduling made a significant difference.

Advice to Future Students

Key recommendations for success with the clock project, based on what worked well for me, are as follows:

• Start early and spread out your work to give yourself flexibility and avoid getting stuck waiting for machines or lab access.
   
• Plan buffer time in case equipment is down or demand is high; having extra time can prevent last-minute stress.
   
• Use your time wisely by aligning your project timeline with lab availability and other course deadlines.
   
• Ask the EMEC staff for help whenever needed. The GTAs and TAs are an invaluable resource and can help you avoid costly mistakes.
   
• Leave time for finishing work so you can elevate the final look. Polishing the components not only enhances your project but may also earn extra credit.
   
• Stay organized and communicate clearly to make the most of your machine time and stay on track with each operation.
   
• Design a unique clock face to make your project stand out. Only two students in my lab section chose to do this, and it was absolutely worth the effort. The artistic finish was the only part of the project that did not require strict precision, so it was a fun opportunity to experiment and be creative.
   

Approach the clock project with a proactive mindset and attention to detail. The more intentional your planning, the more confident and capable you will feel during every stage of the build.

Modern manufacturing techniques can significantly enhance the production efficiency, consistency, and scalability of both clock types. Below are tailored recommendations for each:

In the earlier part of this project, I calculated the cost of building one clock entirely by hand. It came out to $95.40 in materials and $1,293.85 in labor, for a total of $1,389.25 per unit. Most of that cost came from labor. In fact, labor made up more than 93 percent of the total.

Now imagine trying to build 10,000 of them.

At that rate, the total cost would be $13,892,500, and it would take around 515,000 hours to do it manually. That is nearly 59 years of full-time work for one person. Clearly, this process is not scalable.

Let's explore how to manufacture the clock more efficiently using automation and real-world production methods.

Machining: To make this project scalable, I would use CNC (Computer Numerical Control) machining. CNC mills and lathes are ideal for high-volume production because they offer speed, precision, and repeatability.

• Clock Face (PMMA, CNC Mill): ~10 minutes per unit. PMMA machines quickly due to its low density and thermal stability, allowing clean cuts and engravings with moderate spindle speeds [17].
   
• Aluminum Base (CNC Mill): ~15 minutes per unit. This includes profile milling, slotting, and pocketing operations commonly performed on aluminum plates using end mills and face mills [18].
   
• Pen and Pencil Holders (CNC Lathe): ~8 minutes per unit. Turning operations for these cylindrical parts are quick when using optimized lathe programming and automatic part changers [19].
   
• Brass Nut (Turret Lathe): ~2 minutes per unit. Turret lathes are ideal for this operation as they allow rapid tool changes and efficient repetition of simple threaded components [20].
   

Total Estimated Machining Time per Clock: Approximately 35 minutes per unit.

Finishing: After machining, each clock needs to be finished for aesthetics, safety, and function. Here is how I would handle each stage:

• Deburring: ~1 minute per unit. Automated deburring tools can efficiently remove sharp edges and burrs left from machining processes [21].
   
• Sanding and Polishing: ~5 minutes per unit. Sanding can be quickly done using an electric rotary sander with assorted grit (60-600) sanding discs or a benchtop belt sander. Bench-top polishers and tumblers can be utilized for aluminum parts [22].
   
• Coating or Anodizing: ~15 minutes per batch. Anodizing aluminum parts in batches using standard commercial anodizing tanks protects the surface and offers optional color finishes to [23].
   
• Clock Face Art: ~2 minutes per unit. Instead of painting each face by hand, I would use low-cost vinyl stickers. These could be pre-cut and applied during assembly. It also gives customers a fun way to personalize their clocks with patterns or custom designs.
   
• Assembly: ~10 minutes per unit. The assembly process could be standardized using jigs and fixtures to speed things up and ensure accuracy. This includes installing the clock mechanism, attaching the hands, and securing the pen and pencil holder.
   

Total Estimated Finishing Time per Clock: Approximately 33 minutes per unit.

Total Estimated Manufacturing Time per Clock: Approximately 68 minutes per unit.

By automating or streamlining each of these steps, I can increase consistency and scale up production without sacrificing quality. Tools like robotic polishers, pneumatic presses, and alignment jigs make these finishing tasks faster and more repeatable in large batches.

To really maximize efficiency, I would use custom setups that allow multiple parts to be machined at once. For example, a fixture that holds five clock faces in a single run could reduce machine downtime and cut production time significantly.

Using automated tool changers would also allow the machines to switch between cutting tools without operator input. This keeps the process flowing and reduces idle time. These strategies are essential when the goal is to produce thousands of units at a consistent quality level.

To make one clock by hand using EMEC methods, the material cost was $95.40, and the manufacturing time was 51.5 hours. Scaling that up, producing 10,000 EMEC clocks would cost $954,000 in materials and take 515,000 hours to complete.

Now compare that to the automated version. A mass-produced clock costs only $16.39 in materials and takes just 1.13 hours to make. Producing 10,000 units allows for bulk purchasing discounts, cutting material costs by 82.8%, from $954,000.00 to $163,914.92. Even more impressive, production time is reduced by 97.8%, from 515,000 hours to just 11,300 hours.

That adds up to more than $790,000 saved in materials alone and a reduction of 503,700 hours of manufacturing time.

Automation transforms this clock from a one-off project into a viable, scalable product. CNC mills and lathes handle nearly every operation, including cutting the PMMA clock face and machining the aluminum base, holders, and even the nut on a turret lathe. This shift shows how powerful the right tools and processes are in modern manufacturing.

Scalability is not just about producing more; it is about making smarter purchasing decisions and choosing machining processes that maximize efficiency from the start.

And while labor was not required in this cost estimate, it raises a new question I cannot ignore: what would the total cost of one mass produced clock be compared to my clock with labor included? I think it is worth finding out.

The cost to produce a single EMEC clock by hand is $1,389.25. In contrast, a clock from a mass production run of 10,000 units costs only $45.15 to make. That is a staggering difference of $1,344.10 per unit.

Applying a standard 100% retail markup, which is commonly used across small business and manufacturing industries to cover overhead and profit margins [26], the retail prices become:

• EMEC Clock: $1,389.25 × 2 = $2,778.50 
• Mass-Produced Clock: $45.15 × 2 = $90.30
   

This means the handcrafted EMEC clock would retail for nearly 31 times the price of its mass-produced counterpart.

This dramatic difference highlights the true power of production method choices. While the EMEC version showcases detailed craftsmanship and time investment, the mass-produced clock delivers scale, affordability, and speed. The difference is not just in the price, it is in the entire philosophy of manufacturing.