Category Archives: Projects

Craft, Hardware, or Software projects I’ve done

Homemade Bokashi (Kitchen composter)

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Laser cut 1/8 inch acrylic support trayBokashi is a Japanese name referring to intensive composting. This Bokashi bucket was made from a Target brand generic cat litter container, a $5 Coleman igloo spout, and some laser cut 1/8 inch acrylic left over from a picture frame. Similar units sell for over $60, and since we were going to buy the cat litter and acrylic anyways, building our own saved quite a bit of money that my wife promptly spent on 3 containers of special Bokashi starter mix. (I argued that we should just throw in some moldy cheese that we also had laying around.) Continue reading →

Tinfoiling an entire office

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Tinfoiled Office My adviser received a promotion to full professor, so my group tinfoiled his office. It took 12 of us six hours, and almost 3000 square feet of aluminum foil. We individually wrapped books, computer cables, ceiling tiles, etc. The effect is best seen via this Quicktime VR panorama. I really recommend you take a look at the Quicktime VR view of the office, it really captured the ambiance wonderfully. Also, when the sun goes down in the late afternoon, the office gets to be painfully bright.

We also installed a new Port-a-Potty door and a congratulating plaque. Continue reading →

Laptop Paint Job

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Laptop Paintjob Finished

Ok, I'll admit it. Ever since I saw Hackers I've wanted a painted laptop. I finally got around to finding a good graphic and painting it onto my IBM x31 Thinkpad. The hardest part was cutting the stencil out. I then lightly coated it with mineral oil to keep the paint from sticking to the stencil. After that, I used rubber cement to hold the stencil to the laptop (being sure to keep the rubber cement off of the holes) and gave it six coats of white spray paint. After it dried I used Turtle Wax polishing paste to remove some of the over-spray, and then edged the white with black ink to give it a sharp edge.

Refilling laptop batteries!

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The Li-Ion battery in my IBM Thinkpad X31 laptop has been getting a bit long in the tooth. Rated at a 4.4 AH capacity new, /proc/acpi/battery/BAT0/info told me that it was only holding 1.8 AH now that it was a few years old. (This is normal for Li-Ion batteries, which degrade over time, even without multiple charge-discharge cycles.)

X31 laptop battery

 A brand new IBM (or Lenovo now) battery costs over a hundred dollars, but by shopping around I was able to find a "compatible" battery for as low as $50. It was only rated at 4.4AH, but that is relatively close to the 2nd generation 4.8AH batteries that IBM/Lenovo sell for twice as much. I started to wonder if it might be cheaper to buy  OEM li-ion cells and simply replace the cells (keeping the case, and charge/discharge electronics). The first step would be to determine what type of Li-Ion cells I'd need to buy, so I decided to open up my old battery.

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Generating power from Dry Ice [CO2 (s)] via a peltier junction

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While exploring alternate energy sources, I decided to try generating electricity by using the latent heat (or lack thereof) in Dry Ice, or solid CO2. The most direct (and solid state) way to generate electricity from a temperature differential is a peltier junction, which a 12V car cooler/heater unit happens to have. The pre-built cooler is also nice as it has a large aluminum bucket in the bottom to act as a heat sync for the dry ice, and a large heat-sink on the air side as well. (The mounting system for the peltier & heat-sink is very critical, so it was nice to find one pre-built.)

 Voltage reading from dry ice  Amp reading from dry ice generator

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