Pay-per-swing Hammers

March 7, 2011 by kris de decker Filed Under: Books, DRM, Hammers, Libraries, Random

pay perswing hammersA reader at Metafilter reacts to the news that Harper Collins is putting a cap on the number of times their ebooks can be loaned out from libraries:

“I’ve argued that the ultimate endpoint for Digital Rights Management (DRM) is the pay-per-swing hammer. This isn’t as unlikely as it seems. Ball bearings in the hammer could be arranged, via electromagnetism, to configurations which either take away much of the force of the blow or leave it somehow off-center, or a dead-on impact. Ubiquitous wireless access will finally mean that microtransactions are more feasible. Press your fob against the hammer and, once your account has been verified, we will rearrange the bearings in the hammerhead to give you a better swing. A penny per swing. At this point, the only hard part would be getting the existing hammers out of circulation.”

Via Things Magazine. Somewhat related: Know your bolts.

How to Make an Adult Soapbox Kart

March 5, 2011 by kris de decker Filed Under: DIY, Gravity Powered Machines, Low-tech cars, Racing, Random

adult soapbox cart

“This guide will teach you the basic aspects you’ll need to consider to make yourself a road-worthy gravity-powered vehicle. Full suspension on gokart wheels, driver restraints, a ridgid frame with roll bar, and balanced drum brakes are features of the example kart I’ve built that weighs in at under 100lb.”

Of course, this thing only works downhill and is useless as a practical means of transport. But could we please get rid of the Indy 500 and the Formula One circus and race these karts instead? Seems like a lot more fun to me. Previously: DIY replicas of 1930s race cars.

Environmental Impacts of Light-Emitting Diodes (LEDs)

March 5, 2011 by kris de decker Filed Under: LEDs, Lighting, Random

leds environmental impact

Light-emitting diodes (LEDs) are advertised as environmentally friendly because they are energy efficient and mercury free. However, the material content of the LEDs, which generally include group III-V semiconductors, presents its own set of potential environmental impacts. The rapid growth in the LED industry implies that, ultimately, LEDs will contribute to the solid waste stream, and could impact resource availability, human health, and ecosystems in much the same way as generic electronic waste (e-waste) from computers and cell phones has generated concern in recent years.

Potential Environmental Impacts of Light-Emitting Diodes (LEDs): Metallic Resources, Toxicity, and Hazardous Waste Classification (pdf).

[Read more…]

Hand Operated Vacuum Cleaners

February 21, 2011 by kris de decker Filed Under: Human power, Obsolete technology, Random, Vacuum cleaners


hand operated vacuum cleaner“The easiest way to utilize pump vacuums (picture below, left) was to have two people operate them. One person would pump the vacuum while a second would use the hose and wand or tools to clean. A common sight was a daughter pumping the handle while mom did the cleaning. Most early vacuum cleaners were expensive for the time. The well-to-do often would purchase the cleaning contraptions to ease the workload of their servants or housekeepers.”


 “Bellows operated vacuums appeared in several styles and shapes. Some early vacuums utilized a single bellows. This made the cleaner less efficient because there was no suction as the bellows closed. Suction was produced only as air rushed into the bellows as it opened. To make the machines more useful, bellows were installed in pairs and offset to allow one to open while the other closed.” Picture right: a bellow-operated Star Vacuum Cleaner.

Hand operated vacuum cleaner 1“In their day, wheel operated vacuums approached the cutting edge of early technology.  They exhibited a sophistication that was not present in earlier vacuum designs.  This style of machine provided powerful and continuous suction for its user.  The increase in vacuum even allowed for larger diameter hoses and bigger cleaning tools.  Typically, one person cranked the wheel while another cleaned with a wand or hand tool.”

“Friction vacuum cleaners are based on an ingenious concept conceived by James Kirby. They utilize the driving force of the rear wheels to power the cleaner. This style of vacuum derives its power when the operator pushes it across the floor. The wheels contact the floor and turn the axle. This energy is transferred to the fan via a worm gear during every forward motion of the machine. The front wheels are connected to a brush roller to create a sweeping action. These machines look like an early electric upright vacuum, but do not need electrical current to run. As a result, they have no electric motor, cord, plug, or switch. This makes them lightweight, quiet, and cost free to use. Friction vacuums were popular well into the 1940’s in communities where electricity was not available.”

More: VacHunter galleries. Thank you, Adriana.

Cash Ropeway in South Africa

January 26, 2011 by kris de decker Filed Under: Obsolete technology, Random, Ropes, Ropeways

cash ropeway in south africa

Low-tech Magazine editor Shameez Joubert spotted this cash ropeway in Grahamstown, South Africa.

Cash ropeways were used in shops from the 1880s to the 1960s. They worked in a similar manner to large-scale cargo ropeways. Bicable cash transportation systems were powered by a catapult device or by separation of the wires, monocable systems were operated by a small electric motor.

The Cash Railway Website is dedicated to cash ropeways and similar systems, but it does not mention any ropeway still in use. The system in the South African shop was installed in the 1960s and it still works. Thank you, Shameez!

Cameroon Blacksmiths

January 13, 2011 by kris de decker Filed Under: Africa, Hand tools, Metal working, Random

cameroon blacksmiths

“On the outskirts of Maroua, the capital of the Extreme North of Cameroon, is a place quite unlike any other in the country. Here a community of blacksmiths practice their craft in the relative cool of a tree grove. Several dozen men with specialized skills are gathered here for a single purpose: to transform piles of scrap iron into finely finished tools, stoves, replacement parts and other useful implements for sale to the local population. Young apprentices learn the craft while operating bellows or shaping wood for tool handles. The production here is performed entirely by hand and on a scale which must be seen to be fully appreciated.”

The Extraordinary Makers of Maroua, via Afrigadget. Related: Innovation in Kenya’s informal economy.