Back Street Heroes : 2020-09-01

SHED BUILT : 75 : 75


rollers - I’ve moved a two-ton lathe by myself like this. Once it’s up on rollers, it’ll go up a ramp without too much aggravatio­n as long as you’ve thought it through (although it’s not really a job for one person at that point). It’s tricky to see how you could arrive constructi­ons attempting to emulate Evel Knievel on a bicycle. It’s at this point that the debate starts to creep in, because most sources list the wheel and axle at this point. Personally, having moved some chunky bits of industrial machinery by hand from around 250BC. Mind you, this is the same bloke that apparently ran naked through the streets shouting “Eureka!”… I’m fairly sure that Archimedes wasn’t a great user of the lever in his daily life but, in fairness, he did sit down and have a think about 2 at the concept of a wheel other than as an evolution of the idea of a roller. With those three out of the way, the next three are the pulley, the screw and the wedge (Fig.4). A pulley is really just a wheel with a groove round it, screws are inclined planes wrapped around a pole, and a wedge is another implementa­tion of the inclined plane. Going back to the beginning of the list, the lever, the ‘classical’ lever is a straight bar that rests on a fulcrum, but somewhere along the line some clever lad put a bend in a bar, and gave it a built-in fulcrum which, I feel, was a stroke of unapprecia­ted genius. Typically, if you’re moving heavy things then you use one of the rollers as the fulcrum, which brings me to another point of contention I have with that list of six simple machines, which is that the wheel with an axle, and the pulley, rely on having a pivot. There’s quite a leap from the idea of a lever, a ramp and a roller, to putting a hole in something and sticking 4 time to time, I want to know what happened to the roller (Fig.3), which was absent from the lists I saw while I was doing a bit of fact checking. Given a decent bar and some rollers, then it’s not too tricky to get most things off the ground, and sitting on the why a lever works (probably in the bath). The next one on the list is the inclined plane (Fig.2), or ramp as most of us’d call it, which we’re all familiar with from loading motorcycle­s into vans and on to trailers, and possibly ill-advised 75 OCTOBER 2020