Turning X-rays into 3d prints with a DIY CT scanner

In this video I'll show how I built a CT scanner and used it to make 3d printed models of animal skeletons and internal geometry of certain objects. This was done using a commercial X-ray unit that was given to me by a Patreon member, but you can also do it with a DIY X-ray (just be very careful about radiation exposure by using a remote controlled system and being far away during the scan).

The scanner uses an old phone as the camera, which is triggerd by a conductive probe that triggers the touch screen when a relay makes electrical contact between the probe and the phone case. The touchscreen probe, X-ray unit, and stepper motor turntable for the scanner are all controlled by an Arduino Uno with a simple control panel for manually moving the turntable and selecting the number of pictures to take in a 360 degree sweep. Typically a good scan should have at least 100 images, although the more the better.

One of the major drawbacks of my system was that the camera is in the path of the X-ray radiation, which creates lots of noise on the image from "hot pixels". I'll eventually fix this using a system of mirrors to take the camera out of the beam, but it wasn't bad enough to ruin the quality of the scan model.

The x-ray images are cropped, converted to greyscale, color-inverted, and have the brightness and contrast touched up using a batch processor plugin in GIMP. Here's a tutorial on that process:

https://www.youtube.com/watch?v=lAQtItwKKvo

You can also use a program like ifranview to do the batch processing. Note that the images will need to be 24-bit (or less) BMP files for the step below:

The rotational images are turned into translational slices using a program called "Cone-beam backprojection tool", which you can find here:

https://elektronika.kvalitne.cz/SW/graphics/cone_beam_backprojection/cone_beam_backprojection_eng.html

The translational slices are then fed into a program called "3d slicer" which is a really powerful tool for visualizing CT scan data and turning it into a 3d mesh that can be used for printing. The program has a ton of really useful tools for tweaking and cleaning up unwanted artifcats from the scanning process to make a clean 3d model. The mesh is then exported as an STL file and printed.

I was able to succesfully duplicate the skulls from a dead rat and a fish head, and was also able to model and print the internal geometry of a pumpkin, so the device does actually work, but it probably needs a little bit of fine tuning.



Music Used:

Kevin MacLeod - Lobby Time
Kevin MacLeod - Groove Groove