"Suspension Bridge" Pot Rack
Industrial Design Case Study
Here's a small project that nicely shows the progression from napkin sketch to model to mockup to fabrication to installation in a short amount of time. For Emily Luchetti, the James Beard Award-winning executive pastry chef (Farallon, Waterbar, The Cavalier, Marlowe, Park Tavern).
Our office was putting an addition on a house in Sausalito, including a large open kitchen. I laid out the entire kitchen - all the cabinetry, counters, sinks, and lighting seen here.
The house opens to a view of the Bay, so my boss gave me a quick sketch for a pot rack that evoked a suspension bridge. The rack would be hung from beams at the ceiling, providing a shelf for pots and bottles, plus a bar from which to hang utensils. The shelf would be frosted glass, acting as a diffuser for spotlights mounted on the ceiling – essentially turning the entire structure into a light fixture as well.
First, I made a quick-and-dirty scale model so we could see what would be meeting at which joints. While the "bridge" idea was conceptually simple, the specifics were complex. What with rods bolted into other rods, "suspension" wires, and cross-bracing wires, a lot of parts were joining other parts. This little model (about 8" long) helped us understand how the various elements came together.
Next I built a full-scale mockup in our office of one of the three segments of the "bridge," using available wood and bicycle brake cables, and testing it with weight. This demonstrated how the structure would work and gave us a sense of the actual size and scale, and the clearance height beneath.
Then I prepared working drawings for the fabricators. They're informal, but sufficient, showing how to:
- Cut, cope, drill, counterbore, and thread the rods
- Cut and drill the sheet metal and metal plate would be cut and drilled
- Weld the plate and rods
- Cut, bend, crimp, and thread the rods.
(Click an image to expand.)
After one fabricator had cut the steel parts, another one had to weld them. Rather than making detailed drawings or verbal descriptions, I simply made jigs for our welder. It was the most mistake-proof way to be sure the parts ended up in the correct orientation – and fastest!
For the hardware nerd:
- Bracket screwed to beam with allen-head screws.
- Vertical rod slotted over bracket and held in place with expansion pin.
- Cable yokes bolted to bracket and rod with allen-head screws and acorn nuts.
- Wire held in yokes with ordinary bicycle spoke nipples threaded onto the wires; cable tension is adjusted by turning them as you would tension a bicycle wheel.