mechanisms

Fascinating 1953 Navy Film Series on Mechanical Computers

Fascinating 1953 Navy Film Series on Mechanical Computers

Before there were electronic computers, there were mechanical computers, and one of the most important uses of these was in directing gunfire on surface warships. Mechanical fire control computers took inputs from manned instruments that visually tracked enemy ships, and also considered variables such as wind speed and direction, the firing ship’s heading and velocity, etc. That information—completely in the form of physical displacements of mechanical movements—was cranked through a complex train of shafts, gears, cams, and differentials that computed the optimal firing solution, and automatically aimed the guns accordingly. This film series, produced by the US Navy in black-and-white sprocket-clatter 1950s glory, explains the general principles of mechanical computation, as applied to fire control systems, in clear and engaging language with nice animated diagrams. It’s been ported to YouTube in seven parts by user navyreviewer. Totally engrossing. [via Boing Boing]

Lovely handmade wooden door latches

Lovely handmade wooden door latches

Matthias Wandel writes:

My dad originally started making wooden door latches for the cottages he built at Amogla camp. Conventionally available doorknobs and strike plates don’t allow for a lot of latitude in terms of dealing with shifts in the buildings from frost heaving. That, and the available door hardware just didn’t suit his style.The door latches pictured above are for the house he built for the main house, more than 10 years after making his first door knobs and latches. They are an evolved version of his original door handles.

Matthias’ site bills itself as “an engineer’s approach to woodworking.” If you like what you see here, chances are you’ll find it worth the click.

How-To:  Trammel of Archimedes

How-To: Trammel of Archimedes

The mechanism known formally as the Trammel of Archimedes (Wikipedia) has practical application, when fitted with a drawing or cutting tool, as an ellipsograph. Otherwise it is fascinating but generally useless, and these qualities have earned it a variety of approximately affectionate epithets: “do nothing machine,” “nothing grinder,” “BS grinder,” and “Kentucky do-nothing” are a […]

Mechanical gate opener comes full circle

Mechanical gate opener comes full circle

EdenTXlocation.jpgBack in 2008, I wrote a series of posts about Alvin E. Gandy’s 1965 patent “Gandy Slide-A-Way” mechanical gate opener, which uses the weight of an approaching vehicle to automatically open and close a remote vehicle gate without electrical power. The story has apparently gotten back around to Mr. Gandy’s surviving family. His niece Annie just commented:

The mechanical elegance of the pop-can stay tab

If you’ve been around long enough to have ever actually blown out your flip-flop, stepped on a pop top, you’ve already got one great reason to appreciate the 1975 introduction of the stay-on tab or stay tab: No more little metal razors littering the beaches.

Now, “Engineer Guy” Bill Hammack helps us appreciate the stay tab for another reason: It’s a little gem of mechanical poetry. There’s a lot going on when you pull that little ring. Bill’s video exegesis of that action, like all Bill’s videos, is a little piece of poetry unto itself. I can’t get enough of ’em. [Thanks, Bill!]