4-bit Adder Built from Mechanical Relays

relay-adder-register-memory

Would you consider this to be doing math the old-fashioned way? Instead of going with silicon-based switching (ie: transistors) this 4-bit adder uses mechanical relays. We like it for its mess of wires (don’t miss the “assembly” page which is arguably the juiciest part of the project). We like it for the neat and tidy finished product. And we like it for the clicky-goodness which surely must bloom from its operation; but alas, we didn’t find a video to stand as testament to this hypothesis.

The larger of the two images seen above is from the register memory stage of the build. The black relay in the bottom right is joined by a ring of siblings that are added around the perimeter of the larger relays before the entire thing is planted in the project box.

Sure, simulators are a great way to understand building blocks of logic structures like an adder. But there’s no better way to fully grip the abstraction of silicon logic than to build one from scratch. Still hovering on our list of “someday” projects is this wooden adder.

[Thanks Alex]

 

A Meccano Pinball Machine

Meccano Pinball

This pinball table is almost entirely out of Meccano Construction Set parts. [Brian Leach]‘s Meccano Pinball Machine features a digit counter, a kick out hole, flippers, and a timer.

The digit counter is likely the most complex part of the build. By sending it an electrical signal, either the ones, tens, or hundreds digit can be incremented. The electrical signal engages an electromagnet, which connects a motor to the wheel to increment the score. A mechanism ensures the next digit is incremented when a digit rolls over from 9 to 0, and allows the counter to be zeroed.

Rolling the ball over the set of rollover switches increments the score. A mechanism is used to ensure that the switch will trigger with a small weight. Arcing was an issue, which was reduced by adding a snubber to suppress the transient.

The pinball machine was demoed at the South East London Meccano Club, and is a great demonstration of what can be built with the construction kit. After the break, check out a video of the pinball machine.

[Read more...]

Retrotechtacular: Singing bird automata

retrotechtacular-birdsong-automata

Our cats were both sleeping near the computer and these videos were driving them nuts. To our ears these birdsongs sound pretty good. They didn’t trick the cats into stalking mode, but they did spark an audible complaint. So the predators aren’t drooling but the mechanical engineers reading this should be. These automata combine the precision of a mechanical clock with a bellows and specialized whistle to recreate birdsong.

You’ve got to hear it for yourself to appreciate the variety produced by the mechanisms. The first video shows off the device seen on the left. This particular model is from the 1890’s and the demo gives a good look at the arms that open and block a passageway to alter the sound. After seeing that link — which was sent in by [Stefan] — we started searching around for more info on the devices. The one pictured to the right turned up. It’s from YouTube user [Singing Bird Boxes] who has many videos showcasing these types of devices. We picked this one because he tried to explain how each part of the mechanism works. These are still being made today, but there’s something magical about seeing one built during the steam age.

We’d like to make Retrotechtacular a weekly feature every Tuesday. Help us out by sending in links to projects that highlight old technology, instructional videos of yore, tours of museums or similar relics.

[Read more...]

Fabricating a mechanical wristwatch at home

diy-mechanical-wristwatch

Our mouth is still agape after digging through [Tom's] watchmaking blog. This gentleman spent several years designing and machining his own mechanical wristwatch. A dozen years ago or so [Tom] answered an ad for an apprentice watchmaker. He worked on watches and came across a book that detailed how timepieces are made. He was told that no-one does it like that anymore, which only fed his curiosity. What he came up with is, to his knowledge, the first timepiece every made in Australia.

It’s no secret that we have a thing for clocks. But we feature digital timepieces almost exclusively. We’ve love mechanical watches too but don’t see them as hobby projects very frequently. After looking at what goes into the mechanism it’s not hard to see why.

[Tom] was faced with a variety of challenges along the way. One of the biggest was having to come up with tools that would let him perform the precise milling work necessary to achieve success. You’ll want to read through his movement design and manufacture posts. He laid out the plan in CAD, but ended up using some hacked together milling tools to get the job done.

[Thanks Amit]

Mechanical Donkey Kong features laser cut Mario

[Martin] just sent in a project he’s been working on that takes Donkey Kong out of the realm of pixels and sprites and puts our hero Mario into a world made of laser cut plywood.

This mechanical version of Donkey Kong uses an Arduino stuffed into an old NES to control Mario jumping over ball bearing ‘barrels.’ The game starts with 12 of these barrels ready to be thrown by our favorite gorilla antagonist, which Mario carefully dodges with the help of a pair of servos.

This is only the first iteration of [Martin]‘s mechanical version of Donkey Kong. The next version will keep the clever means of notifying the player if Mario is crushed by a barrel – a simple magnet glued to the back of the Mario piece – and will be shown at the UK Maker Faire next year.

Although [Martin]‘s ideas for a mechanical version of Donkey Kong aren’t fully realized with this build, it’s already a build equal to electromechanical Pong.

Mechanical Skeeball built from Knex

We don’t really know what to say. This Skeeball cabinet is built entirely from Knex. It works exactly how you’d expect Skeeball to work. You plug in quarter and it dispenses balls and keeps score.

[Shadowman39] worked on the build for more than a year. Everything that went into it is a Knex part with the exception of a few rubber bands, and the paper numbers that are used on the scoreboard. There are six motors which drive the machine. Four of them are responsible for turning the scoreboard digits, the others handle ball return.

The link at the top starts off with a bunch of images of the various parts, but you’ll want to watch the video after the break for a closer look. It shows the coin hopper in greater detail. It’s built to only accept quarters and to reject all other coins.

[Read more...]

Antique Electromechanical Calculating Machines

electromechanical calculator Hamann 505

The decision to use electronics for our calculating machines has long been decided.  However, that doesn’t mean that mechanical engineers didn’t put up a valiant, if ultimately futile, fight. [Dvice.com] has an interesting article comparing the calculating technology of the 1960s, such as the [Haman 505], to today’s iPad.

This comparison and pictures were made possible by [Mark Glusker]‘s excellent collection.  These models can be divided into two categories, rotary calculators, and printing calculators. According to [Mark]‘s site, the printing calculators stayed on the market a few years after the rotary calculators, which were off the market by 1970.

Although we may never see machines like these made again, anyone even a little bit mechanically inclined would be hard pressed not to be inspired by this collection. Be sure to check out the video of a [Madas 20BTG] calculator after the break to see what one of the rotary models looks like in action! [Read more...]

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