14 Wheel Drive Vehicle Climbs Over Most Things

What do you get when you cross 7 hobby gearboxes with 14 wheels and a LiPo battery? Instead of speculating an answer, we can just check out one of [rctestflight’s] projects.

He came across those hobby gearboxes and thought it would be fun to build a 14 wheel drive contraption. Each gearbox has its own motor and is wrapped up in a nice tidy package also including the axle and wheels. All of the wheels mounted on a straight board wouldn’t be much fun so [rctestflight] used heavy duty zip ties that act as a flexible frame to connect one gearbox to the next. This allows the vehicle to bend and climb over obstacles while keeping as many wheels in contact with the ground as possible.

14 Wheel Drive

All 7 motors are powered by a single cell LiPo battery. In the video after the break it appears the vehicle can steer or that it is remotely controlled, but that is not the case. Once the battery is plugged in it just goes forward. This isn’t the first time one of [rctestflight’s] projects has been featured on Hackaday, check out his Free Falling Quadcopter Experiment.

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DIY Thermal Insert Press

You might not know what a threaded insert is, but chances are you’ve seen one before. Threaded inserts are small metal (typically brass) inserts that are pressed into plastic to give a strong point of attachment for bolts and screws. These inserts are a huge step up from screwing or bolting directly into tapped plastic holes since the brass threads are very strong compared to the plastic. The only major downside to these inserts is that the press to install them is incredibly expensive. Thankfully, [Alex Rich] came up with a cheap solution: a modified soldering iron mounted to an Arbor press.

Commercial threaded insert presses typically use ultrasonic welding or heat welding to fuse inserts with plastic. [Alex] chose the simple route and went with heat welding, which (as you might imagine) is way simpler than ultrasonic welding. To provide the heat, [Alex] mounted a 100W Weller soldering iron to the press, which he says handles the impact with no problem. Unfortunately the copper tips of the Weller just wouldn’t hold up to the impact, so [Alex] made his own tips out of some brass he turned on a lathe.

If, like most people, you don’t have the capability of making injection-molded cases, let alone an Arbor press on hand, you’re not out of luck! Using this same technique people have successfully added thermal inserts to 3d-printed parts using a soldering iron and much smaller DIY presses. Have any ideas on how you could use thermal inserts in your 3d prints? Let us know in the comments.

4-bit Adder Built from Mechanical Relays


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.

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Retrotechtacular: Singing bird 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.

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Fabricating a mechanical wristwatch at home


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.