THE CLOCK
the clock was machined using a variety of tools and processes, but most of the work was done on the mill and the lathe. It consists of two pen holders, (one brass, and one steel), an engraved aluminum base, and a laser engraved acrylic face, which holds the clock mechanics.
WHAT I LEARNED
I had a friend who had taken this class the semester prior, and I was always stunned at how many hours he poured into this thing. I confidently told him I could make it in half the time, maybe even a quarter, after all it looked so simple. 3 out of tolerance brass pieces, and 10 hours of lathe work later, I apologized. I never understood how complex the things we see every day are until I made the clock. The precision needed to make basic objects left me stunned and frankly in awe of the world we live in. I was staring at trash cans and lamp posts on my walk home from the EMEC, trying to imaging someone making it by hand. besides the skills I learned, the most profound thing I walked away with was a new sense of respect and wonder for manufacturing.
TIPS FOR THE NEXT STUDENTS
Work hard and work early, it takes longer than you think,
Don't be afraid to ask questions, I broke a mill because I was too embarrassed to ask how it worked.
COST OF MAUFACTURINGBY HAND
Assuming the machines required to make the parts are all accessible, let's look at how much it would cost to make this clock by hand.
(cost rounded to nearest Doller)
(stock priced at McMaster-Carr)
Hourly wage for a Machinist: $28 (via U.S Bureau of Labor Statistics)
Hours spent: 40
Cost of 5/8 6' brass stock: $21
Cost of 5/8 6' 1018 steel stock: $5
Cost of 12' long 3/8 x 2' 6061 aluminum stock: $11
Cost of Acrylic face 1/8' x 6' x 6': $3
Cost of Rockler clock Kit: $10
Total Cost: $1,170
Yikes! that really puts into perspective how important automation is in our world. there just isn't enough time and manpower to build all the things we want, especially when there's a higher volume of the product demanded. let's look at how much it would cost to manufacture 10,000 clocks, but this time, we'll look at it though the lense of automation.
COST TO MANUFACTURE 10,000 WITH AUTOMATION
Before we tackle the cost of making 10,000 clocks, there's some things we can change to make the process more efficient. First off, the tolerances on the clock are too tight for what it's doing. We'll loosen these up to allow for more efficient manufacturing processes. because we were previously limited to one clock, we had to get the smallest pieces of stock available that could be made into the desired piece. Now we can buy in bulk and cut the pieces to size, which is cheaper. While your first thought might be to CNC the whole thing, that still requires an operator and is better suited for parts with high variance. we'll us closed die forging for the pen holders, and there will be an assembly line with taps and dies for the threads. A similar line will be made for the aluminum, where the piece will be held in place, and drilled. for the acrylic, an automated machine can be made to cut the pieces to shape quicky. At the end of the line, the products will be assembled by workers, who are each only responsible for putting one part into place. Now that we have an idea of how it will be built, let's look at the cost.
brass piece length: 2.5'
10,000 x 2.5' = 25,000'/12= 2083ft
cost per 6ft: $112
2083/6 = 347 rods
347 x 112 = $38,889
Steel Piece length: 2.5'
cost per 12ft = 41
2083/12 = 174 rods
174 x 41 =$7,117
aluminum length: 8in x 10000 = 80,000/ 12 = 6667 ft
cost per 12 ft=$81
6667/12 = 556 x 81 =45,000$
since it's already to shape, we'll use the acrylic from the last one
Acrylic cost: 3 x 10,000 = 30,000$
Clock kit cost: 10 x 10,000 = 100,000
total cost: $191,006
While that might seem like a lot, that brings out clock down to a cost of about 19 dollars per unit. over 50 times cheaper then the cost for the made-by-hand clock.