I’m happy to share my latest project, “The RasPi MilliTome: A Manual Sand Slicer for 3D Reconstruction,” which has just been published on Instructables — and even more exciting, it has been featured by their editorial team in the Teachers Section.

This project is a simplified, hands-on version of my earlier Magic Sand Slicer. Instead of a fully automated mechanism, the RasPi MilliTome is a manually operated device designed to be easier to build while still demonstrating the same fundamental idea: how a three-dimensional structure can be reconstructed from a sequence of two-dimensional slices.

Using coloured kinetic sand, the device allows you to physically “scan” an object layer by layer. Each slice is captured using a Raspberry Pi camera, producing an image stack that can later be processed for 3D reconstruction. The result is a tangible and visual way to understand concepts that are widely used in science, from microscopy to medical imaging.

What makes this project particularly rewarding is its educational potential. It brings together:

• 3D printing and mechanical design
• image acquisition and computer vision
• data processing and reconstruction
• and, importantly, the historical roots of serial sectioning techniques

The fact that it has been highlighted by the Instructables team in the Teachers Section reinforces its value as a STEM learning tool.

In the accompanying guide, I also show how the collected images can be processed using tools like ImageJ, while a more programmable Python-based pipeline is currently under development to further explore segmentation and volumetric reconstruction.

If you’re interested in building your own version, experimenting with image reconstruction, or simply exploring the intersection between hands-on making and scientific concepts, I invite you to check out the full project.

👉 The RasPi MilliTome: A Manual Sand Slicer for 3D Reconstruction

I hope you enjoy it—and if you build your own version, I’d love to hear about it!

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