"News misleads, is irrelevant, has no explanatory power, is toxic, increases cognitive errors, inhibits thinking, works like a drug, wastes time, makes us passive and kills creativity." Read more: Avoid News (pdf). Via Metafilter and The Guardian.
The Making of a Foot Powered Treadle Lathe
April 22, 2013 by Filed Under: Craftsmanship, DIY, Lathes, Random, Video, Wood, Woodworking
“Hi everybody my name is Chris. I choose my woodworking projects based on whatever happens to inspire me”.
In this video, Chris builds a foot powered treadle lathe. Great project, great video.
Via Old Engineering.
Previously:
- Make your own treadle lathe (PDF plans)
- Robin Wood, bowlturner (video)
- The battle of the bowlturners (video)
Victorian Nanotech
April 22, 2013 by Filed Under: Craftsmanship
“I didn’t know much about watches until my aunt died and I inherited an astonishingly beautiful pocket watch from her. Looking online, I found it was made in Switzerland around 1800. It didn’t run, and when I opened the case I thought some small worm had got trapped inside. On closer inspection it wasn’t a worm but the tiniest chain I had ever seen, a perfect microscopic bicycle chain with links smaller than half a millimetre.”
Artist and maker Tim Hunkin repairs Victorian watches. On the picture: a 1908 Waltham pocket watch, Tim Hunkin.
Solar Wood Drying Kiln
“Lumber is usually dried to a specific moisture content prior to further manufacturing or use. While lumber can be air-dried, the humidity in most localities prevents the lumber from reaching the moisture content required for the stability needed for interior use. The kiln discussed is designed to be inexpensive to construct and be simple to operate.”
“The solar kiln described was designed, constructed, and tested at Virginia Tech. This design is based on 25 years of research and development on the solar drying of lumber in the United States and foreign countries. Drawings for two versions of this kiln are available; one for 800-1,000 bd ft and the other for 1,500-2,000 board feet of lumber. Both kilns will dry a load of lumber in approximately one month of moderately sunny weather at its location in Blacksburg, VA.”
“Drying lumber can be a complex process where accelerating drying without having quality loss often requires extensive knowledge and experience. The design of the Virginia Tech solar kiln is such that extensive knowledge, experience and control are not required. The size of the collector keeps the kiln from over-heating and causing checking and splitting of the wood. The kiln is simple to construct and utilizes a passive solar collector, four insulated walls and an insulated floor. The roof is made of clear, greenhouse rated, corrugated polyethylene.”
The Limits of Animal Powered Transportation: Table Top Wool Wagons
April 11, 2013 by Filed Under: Animal power, Random
The Table Top Wool Wagon is among the largest animal-drawn road vehicles ever built. It was a unique Australian invention, built to transport wool from sheep farms to train stations and harbours.
As many as forty bullocks, or thirty horses, pulled the vehicles over distances of up to 1600 km.
Table Top Wool Wagons (also known as “jinkers” or “ships of the desert”) appeared at the end of the nineteenth century and remained in use until the 1920s, when they were replaced by trucks.
Ride Your Bike Faster or With Less Effort Using a Partial Fairing
April 3, 2013 by Filed Under: Bicycles, Bikes, Pedal power, Random
The rolling friction of the tyres is the main resistance acting on a bicycle at speeds below 10 km/h (6 mph). At higher speeds, air resistance becomes far more important. It accounts for more than 80 percent of the total force acting to slow the vehicle at a speed of 35 km/h (22 mph). At this speed, it would take a power output of 345 watts just to overcome air drag when riding an upright commuting bike (on a level road in calm conditions). Riding a velomobile (a recumbent cycle with a fairing) can lower air resistance dramatically, reducing power to overcome drag to about 30 watts at a speed of 35 km/h.
However, velomobiles are expensive. A much cheaper option is the use of a partial fairing. These wind screens, made of shatter resistant polycarbonate plastic, are mounted at the handlebars. A partial fairing is placed so that the rider is able to see over it, not through it. Apart from reducing air resistance, it is also an effective shield against bugs, rain, cold air, and road debris.
Partial fairings are available for different types of upright bicycles, and for recumbents. They weigh between 600 grams and 1.5 kg, depending on the model, including mounts. These accessoiries, which can often be seen on motorcycles, are relatively unknown to cyclists, mainly because they are outlawed in conventional bicycle racing.
When used in combination with a road bike in touring position (with the hands on the handlebar), a partial fairing brings the power required to overcome air resistance at 35 km/h down to 157 watts. This compares to 220 watts for an unfaired road bike in touring position, and to 176 watts for an unfaired road bike in (a much less comfortable) crouched position and wearing tight clothing. A partial fairing on a road bike thus offers a similar advantage to that of an unfaired recumbent (148 watts). With a headwind, the advantage of improved aerodynamics becomes even larger. One disadvantage of fairings is their sensitivity for crosswinds gusts. It takes some practice to get used to them.
The numbers above were taken from “Bicycling Science” (third edition), by David Gordon Wilson, pp 188. The result for the partial fairing concerns an older model, so it might be an underestimation. Picture: a small partial fairing by Zzipper.
