What Is Kinetic Art? Movement, Machines and Rolling Ball Sculpture

What Is Kinetic Art?

Kinetic art is, in the simplest terms, art that moves. But it is more than just an object in motion. The movement is an intentional part of the artwork itself, designed to entertain, capture your attention, create surprise or make you wonder how something works. "Art," of course, is subjective. For some people it can be a banana taped to a wall. For others, it is the intentional building of an object that is interesting to look at, but when put into motion it elevates and entertains in a way that something static cannot. That second definition is much closer to the kind of kinetic art I have been making for more than 20 years.

My particular form of kinetic art is the rolling ball sculpture, sometimes described as a kinetic marble sculpture, rolling marble sculpture, kinetic ball machine or ball machine. I use stainless steel tracks, gravity, motors, lifts and mechanical elements to send glass marbles through a sculpture on multiple paths. Whatever you choose to call them, the basic idea is the same: the movement of the ball is an intentional part of the artwork. The sculpture itself matters, but so does everything that happens when I turn it on. Balls roll, spin, loop, zig-zag, change direction, trigger mechanical elements and eventually return to the lift to begin the trip again. To me, the movement isn't something added to the sculpture. The movement is the sculpture.

A Lifelong Fascination With Movement

I have always been interested in movement. Anytime I see a mechanical machine, I'm drawn to it. I want to understand how it operates, how the different parts are connected and what makes it do what it's supposed to do. That fascination goes back much farther than my first rolling ball sculpture. I grew up next to a creek and was constantly mesmerized by the never-ending flow of water. I watched how it interacted with the physical world around it and how its movement was controlled by gravity, terrain and the obstacles in its path. I spent hundreds of hours in the yard digging trenches, diverting water and watching it flow and move dirt particles around. Boring? Not to me. I thought it was fascinating.

Looking back, there is a pretty obvious connection between watching water find its way downhill and what I do today. Watching rolling marbles move through one of my sculptures isn't all that different from watching the creek water I was fascinated with as a kid. Both are governed by gravity, slope, momentum and the physical path in front of them. I can make a marble accelerate, slow down, change direction, spiral, loop, trigger another object or disappear behind one section of the sculpture and emerge somewhere unexpected. But I can't change the laws of physics. I have to work within them. That's a big part of what makes kinetic art interesting to me.

How Does Kinetic Art Move?

Kinetic artists create movement in many different ways. Some kinetic sculptures are moved by wind or water. Others use motors, gears, counterweights, magnets, springs or interaction from the viewer. Some rely almost entirely on gravity. My rolling ball sculptures use a combination of gravity and mechanical systems. An electric lift carries the marbles upward, giving them the potential energy they need for another trip through the sculpture. In that sense, a rolling ball sculpture is also a kinetic ball machine - the mechanism continuously lifts and recirculates the balls, while gravity provides the movement through the artwork.

Once released at the top, gravity takes over. From there, the tracks and mechanical elements control what happens. A ball might travel through a loop-d-loop, wind around a tall spiral, roll through a horizontal or vertical zig-zag, activate a tipping arm, spin a large wheel or encounter a track splitter that determines which path it will take. On more complex sculptures, several tracks can cross through the same space, creating near misses and making it difficult to tell at first glance where any particular marble is headed.

Eventually all of those paths lead back to the bottom, where the marbles are collected and returned to the lift. The process repeats for as long as the sculpture is running. That continuous cycle is one of the things I enjoy about rolling ball kinetic art. There isn't really a beginning or an end. You can walk up to a sculpture at any moment and enter the action wherever it happens to be.

I Don't Know What the Finished Sculpture Will Look Like

People sometimes assume that a complicated kinetic sculpture must be completely designed before construction begins. That isn't how I work. Before starting a project, I generally know what the frame will look like. I know what type of ball lift I am going to build, and I usually have ideas for some of the elements I want to include. Maybe the sculpture will have several connected spinners, a series of tall spirals on the same path, a loop-d-loop or lots of zig-zags. But I don't have a picture in my mind of the finished sculpture. I don't know exactly where those elements will be installed or how the tracks will travel between them. That develops as I build.

I start with the frame and the lift. Once those establish the physical space I have to work within, I begin adding structure, tracks and elements. One section creates possibilities for the next. Sometimes a space that looked large at the beginning suddenly becomes the perfect location for a particular element. Other times I have to route a track through a very small opening between things I have already built. The sculpture gradually reveals itself through the construction process. For me, that's much more interesting than fabricating something from a completely finished drawing. I get to solve the mechanical and visual problems as they appear.

What Makes a Good Kinetic Element?

A good element should feel like it belongs naturally in the path of the ball. I particularly like movement that creates surprise. A marble can make an unexpected turn, suddenly change direction or enter an element where the viewer can't immediately predict where it will come out. Variety is also important. I try to use different types of movement throughout my rolling ball sculptures because watching the same action repeatedly isn't nearly as interesting. Spirals, loops, tipping arms, spinners, zig-zags, long sweeping tracks and mechanical devices all behave differently. Put them together and you begin to see how many different things can happen while still working within the simple framework of a ball rolling downhill.

Sometimes a client requests a sculpture made almost entirely from tracks rather than mechanical elements. Even then, I try to twist and turn those paths in interesting ways, changing direction, elevation and shape to keep the viewer following the movement. The limitation is actually part of the challenge: How many interesting things can I make happen to a ball when gravity is always pulling it in the same direction? After hundreds of sculptures, I'm still finding different answers.

Sometimes Physics Says No

One difference between kinetic art and a static sculpture is that something can look exactly right and still be completely wrong. It has to work. I've had plenty of ideas that seemed good in my head but failed once I put welding to metal and actually built them. One example is a gravity well I have tried to make several times using only wound stainless steel track rods. The idea was something similar to a flat spiral, but with the center much deeper and the rails wound very close together. In my head, the ball would circle the outside and gradually spiral toward the center. It looked like it should work. It didn't. The track wasn't smooth enough for the motion I wanted. Instead of continuing to circle gracefully toward the center, the marble lost speed and simply dropped through. Good try. No go. So I learned from it and found another solution.

I've also experimented with 3D-printed components. Mechanically, a printed part can work perfectly well. Visually, though, I found that plastic just doesn't look right to me when it is surrounded by a sea of welded stainless steel rods. A successful solution has to satisfy both sides of the sculpture. It has to function, but it also has to belong. That's an important part of building kinetic sculpture. Physics doesn't care how much I like an idea. If the ball doesn't make it through the element reliably, I either modify it until it does or cut it out and try something else. I eventually settled on repurposing lids from pots and pans. Not exactly the shape I want, but they work excellent.

Designing the Sound of Movement

Movement also creates sound. A rolling ball sculpture will never be completely silent. Glass marbles rolling along stainless steel tracks have a sound of their own. But over roughly the last ten years, I've put a lot of effort into eliminating unnecessary noise from my sculptures. There are many potential sources. Track splitters move. Tipping arms return to position. Marbles transfer between tracks. Motors and mechanical lifts operate continuously. A ball simply dropping from one steel track onto another can create a surprisingly harsh sound. Whenever possible, instead of allowing the ball to fall, I'll build a gently curved rail or transition that catches it and redirects the movement smoothly onto the next section.

I've also changed the motors I use. Modern motors allow me to build lifts that operate very quietly. The whine of an electric motor can be surprisingly distracting when you're trying to enjoy the movement of the sculpture. Quieting the mechanisms lets the natural sounds of the sculpture remain - the marble rolling along the rails, entering a spiral or interacting with an element - without the machinery overwhelming the experience. It's something I didn't think nearly as much about when I first began building these sculptures. After living with them for more than two decades, sound has become another material I consider while I'm building.

Kinetic Art Makes the Viewer Participate

One of my favorite things about exhibiting rolling ball sculptures is watching other people watch them. People react very differently. Some walk past with barely a glance. Others stop and watch for a minute or two. Then there are the people who become completely captivated and stand there for quite some time. Those are often the people who begin trying to figure the sculpture out. They follow a marble until it disappears onto another track. They trace paths backward to discover where they originate. If one track splits into two or three, they start watching to see which route the next marble will take. They notice a mechanical element and wait for another ball to arrive so they can see exactly how it works.

I've seen these reactions at shows and with sculptures installed in homes, museums, hospitals, hotels and other public spaces. It's an interesting little lesson in humanity. We're all wired differently, and something that barely registers for one person can completely capture the attention of another. This is also one reason rolling ball sculptures can work particularly well as kinetic art installations in public spaces. The movement attracts attention from across a room, while the complexity gives people something to investigate once they get closer. You aren't only looking at the object. You're anticipating what it will do next.

When Is a Kinetic Sculpture Finished?

My simplest definition of a successful rolling ball sculpture is this: The balls never come off the tracks, never get stuck and never back up. Nowadays, achieving that is fairly straightforward, but every project still presents its own challenges. More importantly, some problems don't reveal themselves immediately. A newly completed sculpture might operate perfectly for two days. And then... not perfectly. A marble comes off a corner that it has successfully traveled through thousands of times. A particular combination of balls causes a backup. A track needs a guardrail. The banking in a turn needs a slight adjustment. Maybe one section just needs a little more slope to keep the marble moving reliably.

That's why I run and test my sculptures for days before considering them finished. A kinetic sculpture doesn't only need to work once for the photograph or video. If it's going into someone's home or a public installation, it needs to continue working through thousands and thousands of cycles. There is an engineering side to that which is inseparable from the artwork.

Kinetic Sculpture: Part Art, Part Machine

That's probably the best way I can describe the kind of kinetic art I make. It is both sculpture and machine. When the power is off, I still want the stainless steel structure to be interesting to look at. The frame, tracks, curves, spirals and mechanical elements create a three-dimensional sculpture on their own. Turn it on, though, and the object changes. The lift begins moving. Marbles appear at the top. Gravity takes control. Tracks that looked like abstract stainless steel lines suddenly reveal their purpose. Spinners turn. Tipping arms move. Balls disappear, reappear, cross paths and eventually find their way back to where they started.

The sculpture becomes an event rather than simply an object. That's what kinetic art means to me. Movement isn't an effect added after the artwork is finished. Movement is one of the materials used to create it. I've been exploring what can be done with that idea through rolling ball sculpture since 2003, and even after hundreds of projects, I'm still finding new ways to make a marble's trip from the top to the bottom interesting.