Daniel De Bruin’s analog 3-D printer uses gravity to force clay through a syringe and onto a slowly-rotating disk. As the disk revolves, a bead of clay is squeezed into a spiral, building a cylindrical pot, one loop at a time.
The machine, hand-built from cogs, gears, and bicycle chains, uses a 33 pound weight to power everything, and the user has to lift the weight back to the top every ten minutes to keep things running.
“3-D printing allows me to create products more swiftly and more efficiently than ever,” says de Bruin on his website. “But these products don’t feel mine.”
The answer was to spend nine months and around $165 building what de Bruin calls “the world’s first mechanical 3-D printer.”
The device is as ingenious as it is mesmerising, and its nuts and bolts appearance belies a subtle complexity. Look a little closer and you’ll see a bent wire. This is what determines the shape of the pot. It’s the software of the machine, if you like. As the rotating plate descends, a guide rod follows the shape of the bent wire and moves the plate accordingly. It’s this semi-automatic aspect, where you could bend an old coat-hanger and have the machine print it into a clay pot, that might be the most appealing part.
“Because there is no external force involved like electricity, it’s still me that’s making the print,” says de Bruin. “Therefore I have a strong connection with the resulting products, these are not products of the machine but products of my hand.”
One problem de Bruin encountered is that of wall size. The nozzle creates a 2 millimeter thick pot wall, but only if the pot is a plain cylinder. As the diameter of the pot increases, so does its circumference, but the syringe still only squeezes out the same amount of clay for every revolution, which stretches the clay out into a thinner bead.
The answer was to slow the disk when the pot grows wider. If you look at the device, you’ll see that there’s one large disk that is connected to the driver weights. Just below it, and overlapping, is another disk (the “follower”). A small wheel is held between the two, and as the follower plate moves according to the bent wire’s shape, this small wheel–which rotates at a constant speed–tracks across the plate’s surface, varying the final speed.
Imagine you have a record player, and that you have a remote-control car with spinning wheels. If you touch the car’s tire down on the edge of the record, the record is driven slowly. Put the same tire near the middle of the record and it spins much faster, even though the car’s wheel is turning at the same speed. It’s an ingenious solution that works to keep the pot walls a uniform thickness, all the way up.
Even though they’re machine printed, de Bruin’s pots looks pretty hand-made, with plenty of glitches thanks to variations in clay flow or wheel speed. He keeps all of these glitches and glazes and fires the results.
“Automated processes ensure that every item meets the same strict criteria, doesn’t deviate from the norm.” he says. “However, deviations are usually the most interesting. As with humankind and nature, true beauty lies in diversity.’