Thousands of travelers will be walking into a body scanner and putting their hands up as they make their way through airport security this holiday season. A tech tinkerer recently completed a homemade version of a backscatter machine using parts purchased on eBay.

Ben Krasnow, as seen from his self-description on Google+, has previously built components for MRI machines. When he’s not working on “top secret projects” at Valve, a video game company, he could probably be found in his home workshop — his favorite place to be, he wrote.

“After work, I spend time on many different types of projects that usually involve circuit design, machining, material selection, and general fabrication/hacking,” he wrote on Google+.

His test subject for the backscatter machine? An ugly Christmas sweater-wearing turkey, in the raw.

(Image: YouTube screenshot)

“Turn to your left. Hold your hands above your head. Hold still for 10 seconds,” he ordered the turkey at the beginning of the video.

(Image: YouTube screenshot)

Turns out the turkey was trying to sneak onto the Thanksgiving dinner table a no-no item. The backscatter machine revealed an Allen key.

Here you can see the metal Allen wrench under the turkey’s sweater. (Image: YouTube screenshot)

Here’s his technical description of how the device was put together:

I built an X-ray backscatter imaging system from parts found on eBay. This system works by scanning a very thin beam of X-rays across the target, and measures the amount of backscatter for a given beam position. The beam is scanned mechanically by a rotating chopper (collimator) wheel, and by tilting the rotating wheel on an orthogonal axis. The output image is generated on an oscilloscope by matching the horizontal scan speed to the rotating wheel, and using a potentiometer to measure the vertical axis position. The scope’s brightness (z axis) is controlled by the amount of backscatter signal received by a large-area detector. Thus, the image is constructed bit by bit. I used a long-exposure shutter on my camera to see the image formed by the moving oscilloscope trace.

He gives a less technical explanation of how it all works in the video. Check it out:

He also wrote that he will be presenting the device at the Exceptionally Hard & Soft Meeting in Berlin in late December.

(H/T: GeekOSystem)