This volumetric display really shows a lot of potential. And it has just the right balance of simplicity and ingenuity. The rig is being developed by [Michel David] and involves a screen shaped like a helix, and a laser which shines through an optical filter disk.
The moving parts of the device are mounted on the same shaft, which is spun by a belt system connected to a Dremel tool. Since the screen and the information disc are mounted on the same shaft, one part of the synchronization process is already taken care of. You can see the separate stand for the projector, which is a laser in this case but is designed to work with other light sources as well. Since the projection surface is moving towards and away from the projector, a laser is preferrable because of focus issues. Unfortunately [Michel] has been having some issues with switching the diode at high enough frequencies. Still, we think the results in the clip after the break are marvelous.
As far as hardware is concerned, this is a lot simpler than trying to spin a large LED matrix.