IDK—Intra-Dimensional Kaleidoscope

Introduction / Abstract:

The objective of this project is to create a volumetric display that is capable of visualizing three dimensional objects in three-dimensional space.

Related products, Works or Inspirations:

• Doom on a Volumetric Display - YouTube
• Voxon | Revolutionary 3D Volumetric Hologram
• Tiny volumetric display - YouTube

We found several strategies for creating volumetric displays during the research phase of our project. The two major types of volumetric displays are either swept volume or static volume, although more recent literature accounts for AR/VR displays.

Swept Volume

• Spin a flat screen around really fast
• What if the screen is curved? Helical? Spherical?
• What if the screen oscillates?
• What if there are mirrors?

Static Volume

• What if we point laser beam into transparent solids?
• What if it’s a gas?
• What if we move a stylus around in a high viscosity liquid?
• What if we stack LCDs?
• Mirrors?

Persistence of Vision

This moving image exploits the "persistence of vision", a characteristic of our retina or brain, to retain an image after it has been removed, enabling us to perceive a whole object.

How does it work:

This project creates the illusion of a 3D shape by spinning a grid of LEDs on a motor. The motor is powered independently via a variable power supply and is electrically isolated from the rotating screen component. The screen assembly consists of a power bank, a wireless controller board, and the LED screen itself. We chose not to power the screen through the same source as the motor to avoid the complexity of using slip rings for power transfer.

For the software, we decided to display a simple moving box on the screen, which appears as a cylinder when viewed in motion. This approach was selected due to challenges in connecting to a local network, largely stemming from the university IT department's restrictions on IoT devices. From a technical perspective, the system was designed to have as few moving parts as possible.

Throughout the design iteration process, we encountered several key challenges. One significant issue was that the motor introduced substantial vibrations when rotating the screen. While we attempted to stabilize the base using gravel and rocks, these measures proved ineffective. As a result, we were unable to safely operate the motor at its full rated speed and had to reduce its power to one-twelfth of its capacity. Although the desired effect was still visible, it was less pronounced due to the reduced speed of the motor.

Summary of Milestones:

For the first milestone, we focused on designing our device. Initially, we planned to use slip rings to maintain a continuous power connection between the motor, micro controller, and screen. However, after consulting with engineers, we decided to phase out this approach. Additionally, we set a target of 1, 800 revolutions per minute (RPM) to achieve a sufficient frame rate for our design.

For Milestone 2, we dedicated significant time to working on the electronics. One of the major challenges we faced was managing the large number of wires required to connect the LEDs. Given that we intended to mount everything on the back of the screen, using jumper wires was clearly not the most efficient solution. Fortunately, we were able to find a board that worked exceptionally well for our needs, as it included a built-in connector for displays like ours, allowing us to eliminate the need for jumper wires entirely.

For our final milestone, we successfully integrated the motor and housing. We designed a custom housing to securely enclose both the motor and the screen components, ensuring a compact and functional setup. Additionally, we finalized the electronics, keeping the configuration minimal yet efficient, to meet the project’s requirements.

Although the housing for the screen and motor are 3D printed, the majority of the hardware was assembled with recycled materials. The motor housing is attached to a stack of 3D printing filament spools, using zip ties. The flanges of the empty 3D filament spools were convenient for stabilizing the base, as they provided additional surface area. The screen housing was secured using M4 and M3 screws, and small adjustable weights were used to shift the center of mass (and reduce vibration) in the final design.