Category Archives: Engineering

Updated Black and Decker Codeless Lawn Mower Review

Update: Less than 2 years old the battery can’t even mow 1/2 of what the old lawn mower battery could mow after it was much older. Unfortunately it seem that even my pessimistic expectations were too high. They managed to provide worse battery product after years of breakthroughs in improving batteries. I would recommend avoiding Black and Decker.

Better options: Toro 20360 e-Cycler 20-Inch 36-Volt Cordless Electric Lawn Mower – Earthwise 60120 20-Inch 24-Volt Cordless Electric Lawn Mower

The bag is indeed much better than the old version but it is the only improvement. The other problems I mentioned do indeed continue to annoy as it is used.

My old version of this mower just stopped working and the repair guy said it would cost $250 for a new starter, new battery… So I bought a new one: Black & Decker 19-Inch 24-Volt Cordless Electric Mulching Lawn Mower #CMM1200. He said that the new ones were not as well manufactured. I couldn’t imagine how you could make things worse (it is a simple product and just adopting improvement over the years should be really easy).

But, the starter on this model is horrible. You have to tun this incredibly cheap key in a very poorly designed socket. Fails over 80% of the time. The old model started easily essentially every time. The design was just as you would expect, foolproof. Whatever pointy haired boss approved this design needs to go into another line of work.

The ability of the mower to cope with high grass is very poor – much worse than the previous model. I had a good test at first given the time between my mower breaking and getting the new one. Not often an issue, but still not a good thing.

They had a poor indication of the charge left in the battery previously. They now provide no indication of the charge left. It makes you realize that a poor indication was much better than none.

Battery technology has improved a great deal, and that was one of biggest the weaknesses of the last one. Well they seem to have managed to provide worse battery performance after 5 years of improvement in that technology. Pretty sad.
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All About Circuits

All About Circuits is an online textbook covering electricity and electronics. Topics covered include: Basic Concepts of Electricity’ OHM’s Law; Electrical Safety; Series and Parallel Circuits; Physics of Conductors and Insulators; Solid-State Device Theory; Binary Arithmetic; Logic Gates; Switches; Digital Storage? It is a great resource. Enjoy.

Mycoremediation and its Applications In Oil Spills

The webcast shows a talk by mycologist Paul Stamets on Bioremediation with Fungi (an Excerpt from Mushrooms as Planetary Healers). In response he to the British Petroleum/Halliburton oil spill he posted a message, Fungi Perfecti: the petroleum problem

Various enzymes (from mushroom mycoremediation) breakdown a wide assortment of hydrocarbon toxins.
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My work with Battelle Laboratories, in collaboration with their scientists, resulted in TAH’s (Total Aromatic Hydrocarbons) in diesel contaminated soil to be reduced from 10,000 ppm to < 200 ppm in 16 weeks from a 25% inoculation rate of oyster (Pleurotus ostreatus) mycelium, allowing the remediated soil to be approved for use as landscaping soil along highways. [paper]
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Aged mycelium from oyster mushrooms (Pleurotus ostreatus) mixed in with ‘compost’ made from woodchips and yard waste (50:50 by volume) resulted in far better degradation of hydrocarbons than oyster mushroom mycelium or compost alone.
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Oyster mushrooms producing on oil contaminated soil (1–2% = 10,000–20,000 ppm)… Soil toxicity reduced in 16 weeks to less than ~ 200 ppm, allowing for plants, worms and other species to inhabit whereas control piles remained toxic to plants and worms.
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New crop of mushrooms form several weeks later [after contaminating with oil]. The spores released by these mushrooms have the potential – as a epigenetic response – to pre-select new strains more adaptive to this oil-saturated substrate.
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I proposed in 1994 that we have Mycological Response Teams (MRTs) in place to react to catastrophic events, from hurricanes to oil spills. We need to preposition composting and mycoremediation centers adjacent to population centers
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On a grand scale, I envision that we, as a people, develop a common myco-ecology of consciousness and address these common goals through the use of mycelium. To do so means we need to spread awareness and information. Please spread the word of mycelium.

Home Engineering: Bird Feeder That Automatically Takes Photos When Birds Feed

During a trip to the Smithsonian last week I found this great home engineering project. Kayty Himelstein and Amy Darr were frustrated: birds came to their bird feeder while they were away at school, so the girls never got to see them. They decided to build a bird feeder that automatically takes pictures of all the birds that came to the feeder. I believe, they used Lego Mindstorms as part of building it.

Top Kill Effort to Stop Oil Leak Initially Working

‘Top kill’ stops gulf oil leak for now, official says

Engineers have at least temporarily stopped the flow of oil and gas into the Gulf of Mexico from a gushing BP well, the federal government’s top oil-spill commander, U.S. Coast Guard Adm. Thad Allen, said Thursday morning.

The “top kill” effort, launched Wednesday afternoon by industry and government engineers, had pumped enough drilling fluid to block oil and gas spewing from the well, Allen said. The pressure from the well was very low, he said, but persisting. The top kill effort is not complete, officials caution.

Once engineers had reduced the well pressure to zero, they were to begin pumping cement into the hole to entomb the well. To help in that effort, he said, engineers also were pumping some debris into the blowout preventer at the top of the well.

Update: The top kill effort failed. BP is now trying to capture the oil as it spills into the water with a funnel like device.

Iron Man 2 Via 3-D Printing

Ever since I first heard of 3-D printing I have though it was very cool. Well first I thought it was science fiction, not real, but a cool idea. Then when I found out it was real I thought it was very cool. Not only is it cool, it is practical. Iron Man 2’s Secret Sauce: 3-D Printing

Maybe the most cutting-edge facet of Iron Man 2’s production was the real-life fabrication of the suits. Using 3-D printers, the film’s production company, Legacy Effects, was able to have artists draw an art concept–and then physically make that concept in just four hours.
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In addition to speed, the benefit is that you can print out costumes custom fitted to the actors, down to the millimeter. And with custom-fitted suits, Robert Downey, Jr. and Mickey Rourke can put a lot more action into their fight scenes, without the wonky effect of layering on too much CGI. (Downey complained that the original Iron Man suits, which were made more traditionally, were too clunky to act in, and extremely uncomfortable.)

Ironmaking at the National Museum of Science and Technology in Stockholm

Joakim Storck discusses pre–industrial Swedish and Japanese techniques for iron and sword making from a museum demonstration at Tekniska museet. Ironmaking at the National museum of science and technology, Stockholm 2005

Bricklaying is a messy story. The mortar consists of clay, sand and horse manure (if available), mixed with water to a fairly loose batter. The best finish is obtained if you work with your hands as the mortar is placed on, and smears with water so that the surface becomes smooth and fine. When then furnace is ready, it is dried through slow heating by wood without blasting, until the moist has been driven out of the mud. At this stage, heating should be quite cautious in order to avoid cracking.

Then, on Friday September 9, we went again with a fully loaded trailer from Dalarna in the direction of Stockholm. More than a few people were probably turning their heads when we passed, because the trailer was dominated by a large bellow — our newly built two chamber bellow with an estimated bladder capacity of up to 800 litres per minute. In addition, we brought fire wood, iron rods, pliers, some stumps and other stuff needed for the furnace operation.
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We made one run each on Saturday and Sunday. Each time we charged a total of about 10kg ore added in amounts of about 1kg every 20 minute. For each charge, we added about twice the amount of charcoal. Discharging of the loupe was scheduled for two o’clock, and by that time a fairly large crowd had gathered to see the show. This time we managed to get the loupe out of the furnace without too much trouble. Worse was that the process took longer than expected, but the crowd seemed to be patient and people stayed around until the end.

Webcast on Finding the Missing Memristor

Very interesting lecture on finding the missing memristor by R. Stanley Williams. From our post in 2008:

How We Found the Missing Memristor By R. Stanley Williams:

For nearly 150 years, the known fundamental passive circuit elements were limited to the capacitor (discovered in 1745), the resistor (1827), and the inductor (1831). Then, in a brilliant but underappreciated 1971 paper, Leon Chua, a professor of electrical engineering at the University of California, Berkeley, predicted the existence of a fourth fundamental device, which he called a memristor.

Green Technology Innovation by College Engineering Students

With prizes totaling more than $100,000 in value, this year’s Climate Leadership Challenge is believed to be the most lucrative college or university competition of its kind in the country. The contest was open to all UW-Madison students.

A device that would help provide electricity efficiently and at low cost in rural areas of developing countries took the top prize – $50,000 – this week in a student competition at the University of Wisconsin-Madison for innovative ideas to counteract climate change.

The “microformer” is the brainchild of Jonathan Lee, Dan Ludois, and Patricio Mendoza, all graduate students in electrical engineering. Besides the cash prize, they will receive a promotional trip worth $5,000 and an option for a free one-year lease in the University Research Park’s new Metro Innovation Center on Madison’s east side.

“We really want to see implementation of the best ideas offered,” said Tracey Holloway, director of the Nelson Institute Center for Sustainability and the Global Environment at UW-Madison, which staged the contest for the second year in a row. “The purpose of this competition is to make an impact on climate change.”

The runner-up for the “most action-ready idea” was a proposal to promote the use of oil from Jatropha curcas plants to fuel special cooking stoves in places like Haiti. UW-Madison seniors Eyleen Chou (mechanical engineering), Jason Lohr (electrical engineering), Tyler Lark (biomedical engineering/mathematics) won $10,000 for their scheme to reduce deforestation by lowering demand for wood charcoal as a cooking fuel.

CORE Concept, a technology that would cut emissions from internal combustion engines by using a greater variety of fuels, won mechanical engineering doctoral students Sage Kokjohn, Derek Splitter, and Reed Hanson $15,000 as the “most innovative technical solution.”

SnowShoe, a smart phone application that would enable shoppers to check the carbon footprint of any item in a grocery store by scanning its bar code, won $15,000 as the “most innovative non-technical solution.” Graduate students Claus Moberg (atmospheric and oceanic science), Jami Morton (environment and resources), and Matt Leudtke (civil and environmental engineering) submitted the idea.

Other finalists were REDCASH, a plan to recycle desalination wastewater for carbon sequestration and hydrogen fuel production, by doctoral student Eric Downes (biophysics) and senior Ian Olson (physics/engineering physics); and Switch, an energy management system that integrates feedback and incentives into social gaming to reduce personal energy use, by doctoral students David Zaks (environment and resources) and Elizabeth Bagley (environment and resources/educational psychology).

Friday Fun: Cats and Kids with iPads

So usable 2 year olds and cats can use them. Fun. Apple sold 500,000 in the first week and demand has outstripped their capacity to produce so they are delaying the international launch of iPad by one month, until the end of May. Google is rumored to have a similar device based on their open Android operating system. Let the games begin. I must admit the iPad seems fun but it seems mainly like hype to me. But I can believe tablet-netbooks could evolve into very cool and popular devices.