Build Your Own CT Scanner

September 15, 2011 by 29 Comments

[Linas] built himself an x-ray generator for a scholarship contest. We assume this wasn’t enough of a challenge for [Linas] because after the x-ray generator was done, he used his project to model objects in 3D (Google Translate link). It’s an amazing build, leaving us feeling sorry for the guy that came in second place to the home-made CT scanner.

The theory behind a CT scanner is fairly simple – take a series of x-rays of an object around an axis of rotation. From there, it’s a fairly simple matter to digitize the x-ray images to produce a 3D model. The hard part is building the x-ray generator. [Linas] used directional x-ray tubes, a few power supplies and from what we can gather x-ray film instead of a CCD sensor. The film was scanned into a computer and reassembled to get a 3D image.

[Linas] doesn’t seem too keen on giving away the schematics for his build to any old joker on the Internet because of the high voltage and radiation components of his build. Still, it’s an amazing build.

Check out the YouTube demo of [Linas]’s CT scanner imaging an old computer mouse and a reconstruction of the same data done in MATLAB after the break.

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Kinect-based Turntable 3D Scanner Looks Very Promising

August 10, 2011 by 22 Comments

We know that the appearance of the Kinect 3D camera hardware, and subsequent open source driver hacking conquest, is a game-changer that brings the real world into much closer contact with the virtual world. But it still amazes us when we see a concept like this turntable-based 3D object scanner that works so incredibly well.

The concept is extremely simple. A box made from foamboard rests atop a turntable. At its center is the object you wish to scan being well-lit by a small LED light source at each upper corner of the box. First up some code and capture data about the sides and top of the object as it spins. To put the shoe back together in the virtual world, he used a modified version of RGBDemo v0.6.0, a Kinect focused project written by Nicolas Burrus.

[A.J] says that the scan comes out pretty well after just one pass, but that’s not stopping him from setting his sights on making this work with three of four Kinects at once. Don’t forget to check out his video demonstration which is embedded after the break.

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DIY Book Scanner Processes 600 Pages/hour

July 18, 2011 by 39 Comments

Like any learned individual, [Justin] has a whole mess of books. Not being tied to the dead-tree format of bound paper, and with e-readers popping up everywhere, he decided to build a low-cost book scanner so an entire library can be carried in a his pocket. If that’s not enough, there’s also a complementary book image processor to assemble the individual pictures into a paginated tome.

The build is pretty simple – just a little bit of black craft board for the camera mount and adjustable book cradle. [Justin] ended up using the CHDK software for the Cannon PowerShot camera to hack in a remote trigger. The scanner can manage to photograph 600 pages an hour, although that would massively increase if he ever moves up to a 2-camera setup.

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DIY Lightbox Repurposes Useless Scanner

April 27, 2011 by 14 Comments

[James] didn’t like losing detail when scanning in photographic negatives, so he repurposed an old scanner and turned it into a lightbox.

The Flickr set of the build shows [James] installing a compact fluorescent bulb in the body of the scanner. Aluminum foil reflects the light, and the scanner glass is painted white for diffusion. [James] is quite happy with the result, and is amazed by the detail seen in the negatives under magnification instead of scanning.

We’re trying to figure out [James]’s though process in deciding to build a light box, and the best we can come up with is the hackaday mantra of, “Of course I can do that myself.” Even though he seems happy with his project, we’re wondering how hackaday readers would improve it. Maybe several dozen red, green, and blue LEDs to adjust the color temperature? Post your ideas in the comments.

Larson Scanner Using 7400 Series Logic Hardware

April 20, 2011 by 11 Comments

[RandomTask] is sharing a Larson scanner he built a few decades ago. These days you can whip one of these up using an Arduino in under an hour. He mentions this, but we agree that for nostalgic purposes there’s nothing like implementing the scanning LED effect using hardware.

Often called a Cylon Eye (after the television show Battlestar Gallactica) or referred to as the lights on the front of Kitt (the car from Knight Rider), the effect doesn’t just involve switching LEDs on and off in the proper order. A true Larson Scanner fades the LEDs as the bright point moves away from them, resulting in a tail that dims over time.

This implementation uses a 555 timer as the clock signal, allowing for speed control through a potentiometer. A counter chip, J-K flipflop, and line decoder all work with each other to address the movement of the brightest light. The fading effect is managed via a capacitor and resistor for each LED. The video after the break shows the pleasing result of this setup.

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Converting A Scanner Into A Touchscreen

March 21, 2011 by 17 Comments

[Sprite_TM] was cleaning up his hacking workbench when he came across an all-in-one device that had seen better days. After a bit of consideration he decided to tear down the scanner portion of the device and ended up turning it into a multi-touch display.

The scanner relies on a long PCB with a line CCD sensor. This sensor is read in a similar way that information is passed along a shift register. Tell it to take a reading, and then start a clock signal to pulse out each analog value from the pixels of the sensor. In order to scan color images it uses multicolored LEDs to take different readings under different illumination.

[Sprite_TM] takes advantage of this functionality to turn it into a multitouch sensor. The sensor board itself is mounted below an LCD display along with a shield with a slit in it to help filter out ambient light. Above the screen a series of LEDs shine down on the sensor. When you break the beams with your finger it casts a series of shadows which are picked up by the sensor and processed in software. Watch the clip after the break to see it for yourself. It has no problem detecting and tracking multiple contact points.

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Make Your Own TSA “Naked” Scanner

December 3, 2010 by 82 Comments

Have you ever wanted to ability to see through objects? Perhaps you have been looking for something special for your own personal TSA role playing adventures? Well, [Jeri Ellsworth] has your back. She has managed to cobble together her own millimeter centimeter wave scanner using a hacked set of Feed Horns (like from a satellite dish) to create the image. By reversing the power transistor on one of the Feed Horns, one of the horns is made into a transmitter, while one of the other horns stays as a receiver. This data is then fed into a FPGA by way of an A2D converter, where an image is assembled when the scanner is moved over a surface. X and Y axis tracking is handled by an optical mouse also controlled by the FPGA, and the whole setup is output to a monitor.

Right now there is no text write up, or any specific details as the hack will vary by whatever Feed Horn is available. However, the video does a great job of explaining some of the electrical concepts, as well as some very useful schematics. Be sure to watch the whole video after the break, and don’t blame us for any health complications, whether the radiation is ionizing or not.

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