Applied Science

I built a CT scanner from an x-ray tube that I bought on eBay, a stepper motor, a large ring bearing, and an Arduino. I used a phosphor screen and my camera to capture x-ray shadow images of a frozen chicken, while the Arduino and stepper motor rotated the chicken by 8 degrees between shots. The resulting 45 images were combined via filtered back projection to create a 3D volume reconstruction of the chicken. Software used: Panasonic SilkyPix (for .RW2 development) Adobe Bridge/Photoshop for image perspective correction Cygwin/Octave for filtered backprojection Cone Beam Computed Tomography algorithm http://www.mathworks.com/matlabcentral/fileexchange/35548-3d-cone-beam-ct-cbct-projection-backprojection-fdk-mlem-reconstruction-codes-for-matlab-students 3D Slicer for visualization and volume rendering http://www.slicer.org/ Axial image stack: https://drive.google.com/file/d/0B4YXWiqYWB99Z3pTRUE5WDZrdVU/

I used my programmable turntable and camera control to create a timelapse video of crystal growth on a small novelty toy. I took one photo (1920x1080) every two minutes, and advanced the turntable by about 3/4 of a degree between photos. I encoded the photos into a 29.97fps timeline in Adobe Premiere, but used two video frames for each photo, so 1 second of playback = 15 photos = 30 minutes. I covered the windows in my shop with black plastic to prevent sunlight from changing the scene as morning arrived. Each exposure was 1/10 at ISO100 f/8, with standard fluorescent lighting in my shop.

I used microscope objective lenses coupled to my Lumix GH1 camera to get these shots. The crystal growth is surprisingly fast. Most of these clips are essentially 1 frame per 8 seconds, so at 30fps playback, 1/240 realtime.

My high-vacuum Penning gauge has been having some problems lately. The last time that I "fixed" it, I used lead solder to create a crushable metal seal between the parts of the gauge body. Eventually the rosin leaked out and probably caused contamination within the gauge. I bought some Indium wire on eBay to replace the metal seals after cleaning the gauge with a bead blaster, sandpaper on glass, and lots of alcohol swabs. Proper explanation of Penning Gauges: http://www.thinksrs.com/downloads/PDFs/ApplicationNotes/IG1hotapp.pdf

For an upcoming project, I'd like to develop a dispensing system that can measure out a desired mass of material. The idea would be to use a microcontroller, dispensing valve, and electronic balance to provide feedback. I already have an American Weigh Scales miniPro-100, and decided to hack it so that my microcontroller can discover how much mass is on the balance. It can then regulate the dispensing valve appropriately. The balance contains a Cirrus CS5530 24-bit ADC. I tapped the clock and data lines and found bursts of data that occurred at 7.5Hz. The clock is about 150KHz. I used a Parallax Propeller running assembly in one of its cores to capture the data stream and load it into my main program.

I am building a machine that will dispense and mix ingredients to make a single cookie. The benefit is that each cookie on the sheet can have its own recipe, and the baker can sample all of the cookies to better understand how ingredient variations will affect taste and texture. In this video, I talk about the butter dispenser. The folks at Meta Mate gave me the idea for customer-rating via QR code. http://www.metamate.cc/

Two of my cleaner laps at Sears Point. My team, Back to the Crapper (#82) placed fifth in our class, and 30th overall out of 180 cars. This is only my third race, and I have a lot to learn about driving.

This video is a response to Grant Thompson's water bottle challenge. Check out Grant Thompson "The King of Random" http://www.thekingofrandom.com You don't need much special equipment to blow mold plastic bottles in a home shop. If I had more time, I would have made a custom wooden form on the lathe, then made a two-part plastic mold around it, and blow molded the bottle into the plaster mold.

I've always liked these bubble tube lamps that used to be built into Christmas tree ornaments, and were also featured in classic jukeboxes. I decided to make one in my own shop and here I explain how they work and how I built one.

Here's an update regarding my cookie machine project.

I've got most of the subsystems on my cookie machine working so that I can dispense desired quantities of one ingredient (sugar). I'm using a UI developed using processing.org, which sends serial commands to a Parallax Propeller microcontroller.

More progress on my cookie-making machine. It's now dispensing flour, eggs, vanilla extract, salt, and white sugar accurately.

I've been working on a Raman spectroscopy setup in my shop for a while, and was finally able to collect some real, verifiable data this evening. Raman Spectroscopy is a technique where light is directed toward a target, and the reflected light is color-shifted by the size and type of the molecular bonds in the target. This is a non-destructive way to determine an object's molecular structure. The problem is that the color-shifted light is many, many times weaker than the non-color-shifted light. A Raman spectroscopy setup compensates for this, and allows meaningful data to be collected.

I built a water circulator that can supply heated or chilled water to various other shop projects. Eurotherm 2132 with platinum RTD (eBay) CPC quick-disconnect hose fittings (eg McMaster 5012K79)

I'm building a physical vapor deposition rig, which will be an interesting tool for creating optical coatings, SEM sample preparation, and maybe even thin film transistors. So far, I only have the pump and Penning gauge connected to the chamber. Soon, I'll have high-current and high-voltage ports in the base plate for controlling the deposition process. http://www.allorings.com/gland_static_axial.htm

I discuss the basics of selecting the right cutter for the job, choosing feeds and speeds, and general setup and planning of CNC milling machine cuts.

I describe how thermocouple vacuum gauges work, and take apart a vintage example of such a system.

I machined a few custom aluminum adapters for KF/NW vacuum fittings on the lathe this weekend. Next time, I hope to have electrical feedthroughs and should be ready to start depositing material!

I've always wanted to create a decorative glass effect known as "glue chipping", and finally got to try it this weekend. My results were OK for a first attempt, and I now know what will work for me when I plan to make a real piece. Some professional work that inspired me: http://www.handletteringforum.com/forum/viewtopic.php?f=2&t=2081&p=7702

I needed to polish two acrylic lenses that were made on a CNC lathe to the best possible finish (hopefully, optical quality). I made some test coupons and tried three different polishing techniques on three different surfaces to see which combination of techniques would yield the best results. The winner was clearly 2000 grit sandpaper followed by Novus No.2 polish. Vapor polishing: http://www.youtube.com/watch?v=bduno3eafcc

In this video, I show my setup for taking focus-stacked images with microscope objectives. I use a Lumix GH1, which is a micro 4/3 format camera, and a custom adapter that lets me interface the camera to a microscope body or directly to a microscope objective. Video-rate focus stacking with a liquid lens: http://www.youtube.com/watch?v=xOyXdnJOHCY CombineZM software for focus stacking: http://hadleyweb.pwp.blueyonder.co.uk/CZM/News.htm Using Photoshop for focus stacking: http://photo.tutsplus.com/articles/post-processing-articles/focus-stacking-made-easy-with-photoshop/

I've put enough work into my thermal evaporator project so that I can actually start using it to create thin films. For my first test, I made some aluminum mirrors on glass, and also coated glass with ITO (Indium Tin Oxide), a transparent conductor used in LCDs and OLEDs. The mirrors look nice, but the ITO was not conductive -- more research required.

I built a small extraction chamber for processing materials with supercritical CO2. Please refer to my previous videos for more information about supercritical co2: http://www.youtube.com/watch?v=-gCTKteN5Y4 http://www.youtube.com/watch?v=TvmM6qa2a90 PDF discussing vanilla extraction with SC CO2: http://www.redalyc.org/pdf/482/48221175004.pdf

I describe how an oscillating quartz crystal can be used to monitor the thickness of deposited coating in a vacuum chamber.

I built another supercritical CO2 chamber for extraction and drying. This time, I wanted a chamber that was easier to open and close, and could be expanded to larger volumes with the same closure system. The chamber is built from 2" OD .25" wall stainless steel, and I welded a plug into one end and a ring with O-ring gland onto the other.

I take apart an electromechanical power meter and describe how it uses magnetic fields to measure power consumed. The voltage coil's numerous turns of wire already provide some phase shift -- the copper ring adds additional shift to bring the total up to 90 degrees.

I take apart a Detectron DG-2 geiger counter, and discover the circuit still works after 60 years!

I try to bridge the gap between in-depth theoretical explanations of heat treatment, and rote tradition.

I'm making flexible printed circuits with my vacuum deposition machine. In this video, I show my first successful active circuit built with copper deposited onto laser printer transparency sheets. My ultimate goal is to make thin film transistors and OLEDs that are deposited onto the substrate.

I have finally been successful in creating a conductive, clear layer of indium-tin oxide on a microscope slide. In this video, I show the process and explain how sputtering works.

I quickly built a game controller to test the idea of generated game inputs from the player's posture (shift in center-of-gravity). This controller is built from a digital bathroom scale and an XBox 360 controller. I used an opamp to convert the bathroom scale's sensor input to a thumbstick input. I also added a mouse to capture yaw.

I show how the photoresist "lift-off" method works to pattern thin films as they are deposited. In this case, I patterned aluminum on a microscope slide.

I wanted to test the idea of using the tongue to control a computer. The most obvious way would be to map x/y coordinates in a Windows-style UI with tongue movements constrained to a plane. This doesn't work terribly well, as even though the tongue has fine motor control, it's very difficult to smoothy achieve the 2D movements needed to operate a system that has been developed around a classic mouse. I think there is possible applications for swipe interfaces, carousel menus, yes/no input, etc.

I've been exploring technology made possible by having clear, patterned electrodes on glass, and succeeded in making a working (barely) LCD. In this video, I explain types of liquid crystal molecules, and how they can be used to make an efficient display.

I've finished my first custom DIY LCD, and describe the process in this video.

I describe how to use plasma to create very clean surfaces on microscope slides. This process is used extensively in the semiconductor industry.

I describe a few more details about the sputter process that I have used to make ITO coatings.