#Installation #LED #Mechatronics #3DPrinting #DMX #TouchDesigner #Meditative

A large-scale installation and exploration of connection and emergent behavior through motion and communion with its viewers. The project was inspired by personal experimental music notation sketches, kinesthetics and body movement patterns, and the liminal spaces we traverse individually and collectively. It is a response to the rhythmic nature of human visual perception as its light sequences shift in response to environmental changes. The installation's elevation increases with each row as the light tubes cascade through the exhibition space.

Group project finished in Spring 2023, exhibited at ITP/IMA Spring Show 2023.

Course: Large-Scale Kinetic Installation with Phil Caridi

Yuxiang Cheng: Mechatronics, Structural Design, Fabrication, Planning, Assembly, Documentation

Meggie Weinheimer: Concept, Software, Light Design, Assembly

Angela Li and David Yang helped with the assembly.

Process

To build a project of this size, planning is crucial. I started by making BoM, ordering parts as the design progressed, and setting a timeline for everyone on the team with the GANT chart.

Structure

The first step is to build the frame that, considering our concept, would be occupying an entire room. For such a huge structure, it was natural for me to build with aluminum extrusions because of how cheap and convenient they are. I started by importing 3030 profiles into Fusion360 and structured them in rows with mechanical stability in mind.

Every single piece of aluminum extrusion is sized according to the standard sizes readily available, with the vertical pieces organized in exponential gradient heights from the first row to the last row and with the rows connected by two 2m extrusions to make them long enough. The bottom pieces are connected with 90-degree angle brackets, while all the vertical parts will be mounted according to the height to balance the cost and the stability.

I also conveniently designed feet for the end of each row for better stability.

Housing

After structuring it, I started to iterate the housing, which is the most important part in the making of this project because there are 15 of them shall be made, with 15 servos, 15 slip rings, 15 light tubes, and 15 other misc accessories that shall be housed in them.

The standard flat housing was iterated and tweaked many many times, too many times to be specified here. Two parts consist of the housing are:

  • A lower part that mounts the housing to the extrusion with four legs that friction-fit the t-slots

  • An upper part that houses the servo with gear, slip ring with wires, bearing, and the geared tube holder that’s holding the tube

Accompanying the height gradient of the vertical extrusions, I also designed three versions of the housing, the flat is for the first three rows; the 45-degree is for the fourth row; and the 90-degree is for the fifth row.

To produce a small batch of complex structures like these, the fabrication of the housing is done through 3D printing, so the design was optimized for it: the two parts are separated to be printed without support on the print bed, and later screw-mounted together with heat-threaded inserts. I printed them with polycarbonate filament for maximum strength.

Lighting

As the heart of the project, the LEDs we used are addressable WS2812s for maximum control. We picked black polycarbonate diffuser tubes for them. The wiring was tricky as light tubes would be sitting on spinning parts. The slip ring is a standard solution in this case, but they are always either too large or too expensive to buy 16. I picked a very cheap kind with thin 28-gauge wires. I then design the schematics to be parallel to control the current load on wires.

We landed on using DMX to control the servo motors because we believed it makes the project’s overall construction more efficient as well as simpler by using one single protocol to control both the lights and motor networks via Touchdesigner.

The LEDs are programmed using Touchdesigner via DMX, sACN protocol & 16 universe pixel controller. The intention was to have the tube construction complete in time to experiment with the numerous possibilities available for programming movement, speed & textures into our 450 points of light. Proposed possible outputs include: communicating natural forms: waves, motion, symmetries to gradual fades. In the end, construction took longer than expected so there was less time to expand on our LED and servo outputs. Many ideas have already been considered for future project iterations.

Installing

With most of the preparation and purchase finished or well-planned (BoM attached at the bottom of the page), we started the installation test before the final show.

Many issues were found and diagnosed for us to improve on later.

Show!

When the assigned installation time started, we moved the structure to the spot. Each row was kept assembled with the vertical parts to save time, but it turns out that moving 4m extrusions downstairs is quite painful.

Indeed, the assembly was intense as all the work here could not be done beforehand

Future Plan

The process of making the project is educative, there are many things that I wish to iterate. I would be organizing and redesigning every part of the project, and turning it into an open-source project. All these improvements are based around PCB, which is a central topic for my works now as it’s the gateway to sharing an electronic object.

  • Motor and Slip Ring: I’m currently learning about the PCB motor, which basically uses printed coils as a BLDC motor. I would like to investigate the possibility of combining it with the PCB slip ring to make the design more compact and DIYable.

  • Wiring: The wiring now is just painful, we needed to solder and test all 16 cables for the LED and servo, picture this: there are 16 x (3(servo) + 2(LED power)) + 15(LED data) wires to take care of. So, I plan to design a simple PCB wire hub for each module that uses standard cables for output.

  • Controller: The DMX boxes we were using are standard and find, but it would be much more compatible and replicatable to have a controller designed by myself, or at least a DMX adapter.