The Deco Can was the first in TOMO's watering can series. Being the first, it's perhaps the most cautious, if not, ironically, the most responsible.
Caution was in order as I didn't yet have good instincts about wall thicknesses, spout hydrodynamics, water entry, handle positioning, and the many other factors that go into making a working 3D printed watering can.
Responsibility, in turn, has not exactly been the strong suit of TOMO. After all, we're an experimental design practice with the goal of advancing the state of the art, not living in its wake. Nevertheless, experimentation could not get in the way of making a smooth-pouring, leak-proof, hand-friendly can.
These weren't objectives so much as hard requirements - the can would be used by long-time program partner Phipps Conservatory and Botanical Gardens. Their garden on our grounds is maintained by a staff of professionals with no time for faulty equipment.
A smooth pour, but an uncomfortable handle
I spent half an hour with their can collection, examining apertures, relative positions, and, most critically, spouts. The poured rosettes, as I learned they're called, varied drastically. Some spouts produced a quick, laminar flow; others were turbulent and narrow. I noticed that an unusual perforation pattern in the bell (with many holes around the outside and none in the center) yielded the best rosette.
Three Phipps gardeners kindly shared advice. Their most alarming request was that the can be a full two gallons. My young students - who, as budding gardeners themselves, can be counted on for fresh insight - provided input too.
Long list of constraints in hand, I got to work in CAD. The smooth, sloping curves of the body emerged almost automatically. I didn't shoot for a platonic form, but the more I accounted for the constraints, the closer it got (observers insisted, at least) to the ur-watering can.
Rhino's new SubD functionality was instrumental in achieving the smooth, sloping curves
My classroom's Ultimaker S5 3D printer, while large, was not nearly large enough to crank out a two gallon can in one piece. So, in my most challenging maneuver, I chopped off the spout and created a brace for it inside the body. The spout would get printed separately and, in a final move, glued into place.
V1 taught me a lot about large format prints
Adding to the brace challenge was the fact that the body would be printed lying on its back (necessary so that water load would be distributed perpendicularly to the 3D printed layers, maximizing strength). Since support material inside the body was a no-no (it wouldn't be removable), geometric acrobatics were needed.
After four days in the printer, the can was ready for testing. It passed with flying colors (in my shower). But with another six months until planting season, it'll be some time until the team battle-tests it in our garden.
V1 completed November, 2021