Tag Archives: home engineering

Home Engineering: Dialysis machine

A baby dying from kidney failure was saved when her doctor designed and built her a dialysis machine from scratch in his garage.
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The job of the kidneys is to ‘clean’ the blood, and if they fail, a dialysis machine can do this job instead.
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However, Dr Coulthard, together with senior children’s kidney nurse Jean Crosier, devised a smaller version, then built it away from the hospital. Millie was connected to the machine over a seven day period, allowing her own kidneys to recover.

Rebecca, from Middlesbrough, said: “It was a green metal box with a few paint marks on it with quite a few wires coming out of it into my daughter – it didn’t look like a normal NHS one.
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The machine is still in use, helping babies in similar circumstances to Millie, but Dr Coulthard told the Newcastle Journal newspaper that an official version was needed. “This machine is only being used on the tiniest, earliest babies where there is nothing else that can be done.

“But if we had a machine that we could use much more freely, then we would be able to deal with many more babies and have a much greater chance of saving lives.”

Babbage Difference Engine In Lego

Building A Calculating Machine Using Lego Pieces by Andrew Carol

Before the day of computers and pocket calculators all mathematics was done by hand. Great effort was expended to compose trigonometric and logarithmic tables for navigation, scientific investigation, and engineering purposes. The larger efforts involved rooms of semi skilled people, called ‘computers’, capable of doing reliable arithmetic who would be under the direction of a skilled mathematician.

In the mid-19th century, people began to design machines to automate this error prone process. Many machines of various designs were eventually built but, the most advanced and famous of these was not. The Babbage Difference Engine.

Because of engineering issues as well as political and personal conflict the Babbage Difference engines construction had to wait until 1991 when the Science Museum in London decided to build the Babbage Difference Engine No.2 for an exhibit on the history of computers.

Babbage’s design could evaluate 7th order polynomials to 31 digits of accuracy. I set out to build a working Difference Engine using standard LEGO parts which could compute 2nd or 3rd order polynomials to 3 or 4 digits. I have built two generations of Difference Engines and am designing the third version now.

BlimpBot Foiled by Air Conditioning

TED BlimpBot Report: Foiled by Air Conditioning!

I had a three-minute slot to show how the prototype works. This was a pretty high-stake demo, since not only would there be 2,000 of the most influential people in the technology, entertainment and design (TED) worlds watching, but they included Al Gore in the FRONT ROW, Google’s Sergey Brin and Larry Page and movie stars such as John Cusack and Goldie Hawn.

The bot worked great in the hotel room, and then we took it the the auditorium during a break to test it on the main stage. Yikes. We were getting IR interference from everything, from LCD screens to the bright stage lights, and our reception range dropped to something around three feet. Even worse, the air currents were overcoming the blimp’s ability to fight them. So we gave up on the idea of a fixed IR beacon on the ground, and I decided to hold it in my hand to keep it near the blimp. Even then, the motors couldn’t fight the currents well enough.
So we rushed back to our staging area (my hotel room) and Jordi updated the firmware to give more power to the motors even at the cost of battery life (this demo only had to run three minutes) . We tested it again in the hotel room, it worked fine, and then it was time to go.
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It turns out that one big thing had changed since our test run in the auditorium: 600 people had arrived. All that body heat had raised the temperature of the room, kicking in the air conditioning, which came out of huge ducts right over the stage. Basically I was under a raging waterfall of cold air, and the poor blimp sank right to the floor, its little vertical thruster completely overcome.

Home Engineering: Physical Gmail Notifier

photo of Gmail Cube

How to make a Physical Gmail Notifier

Every so often, the computer checks for new emails in your Gmail account, and then tells the electronics board whether any have arrived. If they have, the board turns on the output device (the cube). Simple.

The hardware itself is the popular Arduino board, the tinkerer’s dream device. I’m actually using a Boarduino, but any variant should work (subject to a small but important detail, see below). This might be particularly interesting with a Bluetooth Arduino..

The Arduino talks with your computer over a serial connection, which runs over the normal USB cable you use to communicate with your Arduino.

What is Arduino?: Arduino is an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software. It’s intended for artists, designers, hobbyists, and anyone interested in creating interactive objects or environments. Arduino can sense the environment by receiving input from a variety of sensors and can affect its surroundings by controlling lights, motors, and other actuators.

Rubick’s Cube Solving Lego Mindstorms Robot

Lego Mindstorms have really really provided some great tools for home robot engineering. JP Brown has several examples on his web site including this CubeSolver:

The longest part of the this project involved writing the color-recognition software. I downloaded the Logitech Quick Cam SDK from the Logitech Developer’s site (the LEGO Vision Cam is a repackaged Logitech Quick Cam) and used VB5 to write a fairly decent program (click the Code link for source). The color recognition is fairly robust (about one error every two cubes when well-calibrated), but not perfect, so I incorporated a feature that requires you to confirm that each face has been correctly scanned (and, optionally, allows you to correct the input manually) before it scans the next face.
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My early attempts at building a cube solver were all stymied by grips that slipped. The worm-56t gave enough torque to turn, but the fingers couldn’t hang on and the grip was simply pried apart as the grabber rotated around the stationary cube face. I thought about changing the device’s name to ButterFingers.

I rebuilt the left and right grabbers six times (and the bottom grabber four times) trying elastic bands, Technic shocks, and pneumatics, before I came up with an adequate grip mechanism. In the present version, an axle runs from a motor through the center of the large Technic turntable to a worm screw. The worm screw turns two 24t gears mounted either side of the worm inside the body of the grabber.

Other home engineering favorites: Awesome Cat Cam – Windmill for Electricity – Lego Autopilot First Flight

The Engineer That Made Your Cat a Photographer

photo by Binky the cat or another cat This article is the result of the first Curious Cat engineer interview. My favorite post detailed the great engineering project Jürgen Perthold undertook to engineer a camera that his cat could wear and take photos. So I decided to interview him.

The Engineer That Made Your Cat a Photographer by John Hunter:

This time I thought about our cat who is the whole day out, returning sometimes hungry sometimes not, sometimes with traces of fights, sometimes he stay also the night out. When he finally returns, I wonder where he was and what he did during his day. This brought me to the idea to equip the cat with a camera. The plan was to put a little camera around his neck which takes every few minutes a picture. After he is returning, the camera would show his day.

The Amazing CatCam is not only a great product but a wonderful engineering story. See our past post for some background on how an engineer allowed you to help your cat become a photographer. On the development of the CatCam Jürgen Perthold says, “More or less it was just a joke, born with a crazy idea.” Such a great sentiment and with wonderful results.

What path led him to the desire and ability to pursue the crazy idea and become the Curious Cat engineer of the year? He was born in Aalen, Germany. He started playing with electronics as he was 13. At 15 he added computer programming and with a friend they programmed games, applications and hardware control over the years. He studied Optoelectronics at the University of Aalen, Germany extending his knowledge further.

For the last few years he has worked for Bosch, an international manufacturing company, in the automotive hardware section. Last summer, he transfered from Germany to Anderson, South Carolina as a resident engineer for transmission control unit in a production plant for automobile parts. On a side note, the United States is still by far the largest manufacturer in the world.
photo by Binkey the cat, from under a car
The demand for the cameras is still higher than his capability to produce the cameras. He has raised the price, to limit the demand. When I first saw the prices I couldn’t believe how inexpensive it was. And, in my opinion, they are still a incredible deal. Order your CatCam now: it is a great gadget for yourself or it makes a great unique, gift. Most orders have been from the UK, Germany and the USA.

Most people don’t have technical background so they buy the full unit. But he reports that some brave souls order a kit because of price or availability although they have not done anything similar before. What a great way to challenge yourself and, if you succeed, end up with a wonderful creation when you finish.

He is in discussion with several different groups to ramp up production. The main problem is that producing the device requires electronics, optics, software, mechanics and logistics expertise. So, for the time being, he continues to modify the cameras by hand because no investments are necessary and the production can be scaled according to the demand. The required soldering, electronics and system knowledge makes it a challenge to outsource. So, for now, CatCam production is adding to the USA manufacturing output total. He is also planning to produce more products.
photo of Jacquie the cat wearing a CatCam
JÃ¼rgen believes that getting the cat camera working was not that challenging. You can take a look at his explanation of how he did so to decide for yourself. He does admit that challenges do arise if you want to produce cameras for others. To do that you must create a product that is foolproof, reliable, and easy to use and manufacture.

“I was surprised how famous one can get with ‘boring’ technical engineering stuff. I like this not only for me but for all other engineers out there who daily work hard on challenges which others don’t even understand. We as engineers make the world moving but usually we are not recognized.” Everyone enjoys the products of the labors of engineers (such as cell phones, MP3 players, cars, planes, bridges, internet connections) but few see the required knowledge, work and the people that bring those products into being.
photo by Jacquie the cat of a vine
JÃ¼rgen “hopes that I made ‘engineering’ a bit more visible to people who did not think about it before, for example, female cat owners who never had a solder iron in the hand and bought plain SOIC chips because they wanted the cat camera…”

I think he has done a great job illustrating the engineering behind the CatCam and making engineering fun. And in so doing hopefully is making more people aware of the engineers that make so many wonderful modern gadgets. Go buy a CatCam now (and if you are adventurous buy the parts and create your own – you will learn a lot about what makes all your modern gadgets work). And then send in the pictures your cat takes so everyone can see the wonderful things engineers make possible.

The photos here show the results of several new cat photographers (Binky the cat [first 2 photos] and Jacquie the cat [last 2]). Only a small percentage of CatCam owners have shared there pictures so far.

Over the next few years he would like to learn to sail, visit Yellowstone national park, walk the Camino de Santiago again, move on to other international assignment (maybe far east) and continuing raising his two children.

The Curious Cat Science and Engineering Blog is written by John Hunter and tracks a wide variety of developments, happenings, interesting under-publicized facts, and cool aspects of science and engineering.

Home Engineering: Windmill for Electricity

photo of windmill

William Kamkwamba’s Malawi Windmill:

I built my first windmill when I was 15. Over the next few years I kept refining the design. I made many modifications to the plans i found in the book. For example, I increased the blades from three to four to provide more power output. The windmill now powers lights for 3 rooms and a light over our porch outside. I also use it to power my family’s two radios. I also can charge mobile phones that the neighbors have.
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Two weeks ago I used a computer for the first time. I learned about Google and searched for “windmill” and “solar energy.” I was amazed to learn how many entries there were for both subjects. My friends showed me how to create an email address and now I am on Gmail. Now I am practicing sending and receiving emails when I have access to a computer.
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On Sunday, my friends from National Solar and I completed the next phase of work on my electrical system. You can see a compete set of (my first) digital photos at my new site on Flickr. I had the following goals:

1. Upgrade the power generation in the windmill
2. Upgrade the battery technology and capacity, to provide more even power for more hours at a time
3. Increase the brightness of the lighting (lumens) to make it easier for my family to accomplish tasks at night, especially to read…

Photo: Back in November, the windmill was only 5 meters (15 feet) tall compared to 12 meters (36 feet) today. I raised the height because I discovered that the best wind was just over the top of the shorter windmill.

Open Source 3-D Printing

3-D Fabrication Goes Open Source

Hod Lipson and Evan Malone of Cornell University have cooked-up a cheap DIY 3-D printer – the Fab@Home – that they believe could lead to the widespread use of fabrication machines by hobbyists and experimenters. Fabrication machines, or fabbers, operate on the same principle as inkjet printers, but instead of squirting out ink onto paper, they squirt plastic or other materials into three-dimensional shapes. Commercial systems average around $100,000, but you can build Cornell’s Fab@Home for about US$2,300 worth of off-the-shelf parts.

Concrete Houses 1919 and 2007

Robo-builder threatens the brickie [the broken link was removed]

Is the writing on the wall for the brickie? Engineers are racing to unveil the world’s first robot capable of building a house at the touch of a button. The first prototype — a watertight shell of a two-storey house built in 24 hours without a single builder on site — will be erected in California before April.

Brickie?: a search seems to indicate that is a bricklayer.

By building almost an entire house from just two materials – concrete and gypsum – the robots will eliminate the need for dozens of traditional components, including floorboards, wooden window frames and possibly even wallpaper. It may eventually be possible to use specially treated gypsum instead of glass window panes. Engineers on both projects say the robots will not only cut costs and avoid human delays but liberate the normal family homes from the conventional designs of pitched roofs, right-angled walls and rectangular windows.

Edison patented a process for constructing concrete buildings in 1908 (1917 issued). Photo is of a concrete Edison house being constructed in one day in Union, NJ on October 9th, 1919. See more photos of concrete houses and much more at the great National Park Service Edison photo gallery [sadly the NPA broke the link and it has been removed].

Automatic Cat Feeder

The Automatic Cat Feeder:

As I dug around this box, I found an old CD Rom drive and power supply. The thought struck me that I could use the ejecting tray of the CD Rom as a solenoid to push the trigger mechanism of some sort of physical contraption. But then I had a bootstrapping problem – what can I use to push the eject button of the CD Rom on schedule?

After some more thought, I realized that I could just use my spare (working) computer as the basis of the cat feeder. It’s also my home’s Subversion source control server – a rare mix of server workloads indeed! It has a CD Rom drive, so I could just use software to open and close it.

And water for the cat too:

Water flows out of the jug as long as the water level is below the hole at the bottom. When water flows out, the air pressure in jug decreases until it sucks in some air to equalize. When the water level covers the hole, though, the air pressure can no longer equalize, so the water flow stops.

When the cats drink the water level down a bit, the jug can once again equalize its air pressure, and lets more water out.

Don’t miss the video – Related: Engineering at Home