mechanism

28 Articles

3D Printed “Book” Demonstrates Mechanical Actions

September 24, 2025 by 22 Comments

A book of mechanical actions is a wondrous thing — mechanically inclined children have lost collective decades pouring over them over the generations. What could possibly be better? Why, if the mechanisms in the book were present, and moved! That’s exactly what [AxelMadeIt] produced for a recent video.

Being just four pages, you might argue this is but a pamphlet. But since it takes up a couple inches of shelf space, it certainly looks like a book from the outside, which is exactly what [AxelMadeIt] was going for. To get a more book-like spine, his hinge design sacrificed opening flat, but since the pages are single-sided, that’s no great sacrifice.

At only 6 mm (1/4″) thick, finding printable mechanisms that could actually fit inside was quite a challenge. If he was machining everything out of brass, that would be room for oodles of layers. But [Axel] wanted to print the parts for this book, so the mechanisms need to be fairly thick. One page has a Roberts linkage and a vault-locking mechanism, another has planetary gears, with angled teeth to keep them from falling out. Finally, the first page has a geneva mechanism, and an escapement, both driven by a TPU belt drive.

All pages are driven from an electric motor that is buried in the last page of the “book”, along with its motor, battery, and a couple of micro-switches to turn it on when you open the book and off again when you reach the last page. Rather than a description of the mechanisms, like most books of mechanical actions, [Axel] used multi-material printing to put lovely poems on each page. A nice pro-tip is that “Futura”, a font made famous by flying to the moon, works very well when printed this way. If you just want to watch him flip through, jump to 8:00 in the video.

This reminds us of another project we once featured, which animated 2100 mechanical mechanisms. While this book can’t offer near that variety, it makes up for it in tactility.

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White pieces on a teal and white chess board. The line of pawns shows three segmented queens in the foreground, one piece being pressed by a man's hand from above in a state between queen and pawn, and the remainder of the pawns in the background in the pawn state.

Transforming Pawn Changes The Game

November 2, 2024 by 15 Comments

3D printing has allowed the hobbyist to turn out all sorts of interesting chess sets with either intricate details or things that are too specialized to warrant a full scale injection molded production run. Now, the magic of 3D printing has allowed [Works By Design] to change the game by making pawns that can automatically transform themselves into queens.

Inspired by a CGI transforming chess piece designed by [Polyfjord], [Works By Design] wanted to make a pawn that could transform itself exist in the real world. What started as a chonky setup with multiple springs and a manually-actuated mechanism eventually was whittled down to a single spring, some pins, and four magnets as vitamins for the 3D printed piece.

We always love getting a peek into the trial-and-error process of a project, especially for something with such a slick-looking final product. Paired with a special chess board with steel in the ends, the magnets in the base activate the transformation sequence when they reach the opposite end.

After you print your own, how about playing chess against the printer? We’d love to see a version machined from metal too.

Thanks to [DjBiohazard] on Discord for the tip!

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Paper Punching Machine Looks Like Cute Piece Of Computer History Past

September 13, 2023 by 23 Comments

Computing used to run on punch cards. Great stacks of cards would run middling programs, with data output onto more punched cards in turn. [Nii] has built a machine in this vein, capable of punching binary into paper tape. 

The machine is run by a stepper motor, which is charged with feeding the paper tape through the machine in steady steps. A series of vertically-actuated solenoids punch holes in the paper tape as directed. The machine buzzes and clicks away like the best electromechanical computing devices of the mid-century era.

To what end, we couldn’t possibly say. One user noted the machine was punching seemingly random binary into the paper tape, and [Nii] has not provided any explanation as to the machine’s higher purpose. Regardless, whatever it is doing, it looks like it’s doing it well. Feel free to speculate in the comments.

Impressively, the petite device will be demonstrated at MF-TOKYO, the 7th Annual Metal Forming Fair in Tokyo this year. We’re sure the clickity-clack will be muchly appreciated in person.  Video after the break.

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An Open Source Modular Flexure Construction Set

November 22, 2022 by 14 Comments

Flexures are one of those innocent-looking mechanisms that one finds inside practically any kind of consumer device. Providing constrained movements with small displacements, complete with controlled tension, they can be rather tricky to design. GrabCAD designer [Vyacheslav Popov] hails from Ukraine, and due to the current situation there, plans to sell a collection of flexure building blocks became difficult. In the end, [Vyacheslav] decided to generously release his work open source, for all to enjoy. This collection is quite extensive, looking like it could solve a huge variety of flexure design problems. (Links to the first three sets: Set00, Set01, Set02 but check the author’s collection page for many others)

It’s not just those super-cheap mechanisms in throw-away gadgets that leverage flexures, it’s much more. The Mars rovers use flexure-based suspension, scientific instruments (interferometers and the like) make use of them for small motions where specific axis constraints are needed, and finally, MEMS accelerometers and gyroscopes are based entirely upon them. We’re not even going to try to name examples of flexures in the natural world. They’re everywhere. And, now we’ve got some more design examples to use, so why not flex your flexure muscles and send one to the 3D printer and have a play?

We see flexures here quite a bit, like this nice demonstration of achievable accuracy. Flexures can make some delicious mechanisms, and neat 3D printable input devices.

Thanks to [Addison] for the tip!

See The Forbidden Cigarette Machine In Action

November 20, 2022 by 66 Comments

[Fraens] has been designing a number of fantastic 3D printed machines and making great videos that demonstrate how they work. The last installment was an automatic cigarette stuffing machine, and it’s got a number of pretty complex motions, and somehow manages to get the job done.

While [Fraens] usually uploads STL files for all of his machines, this one is forbidden! Selling automatic cigarette loaders is illegal in Europe, and it’s not clear how close to the legal edge posting them up on Thingiverse is. So until the legal dust settles, you’re going to have to be content with the fantastic video, also embedded below.

But honestly, the devil’s sticks aren’t good for your health anyway, and you’re probably just in it for the mechanicals. Think for a moment about the problem – you’ve got a hopper of tobacco fibers that all like to stick together, and you need to pack them into an easily squished lightweight paper tube. These tubes aren’t easy to handle either. The solution to both of these calls for solenoid-powered tappers that agitate both into place.

There’s also a 3D printed rack and pinion to do the pushing, and a cool stepper-driven revolver mechanism to put the empty papers into just the right place. The machine leans heavily on 3D printing, but also on simple hardware-store parts like aluminum and brass tubes. [Fraens]’s builds are always simple but simultaneously very slick, and you’ll learn a lot from watching it all go together.

And when you’re done, check out some others from [Fraens]. We’ve been impressed by his sewing machine, braiding machine, and even a power loom.

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A 3D Printed Marble Run Features Neat Elevator Linkage

September 21, 2022 by 20 Comments

There’s seldom anything as joyful and relaxing to watch as a simple marble run. Of course, the thing about letting marbles fall under gravity is that you eventually need to lift them back up again. The Marblevator has a mechanism that does just that.

Overall, the build features a relatively simple marble run. It consists of just six 3D printed ramps which the marble tumbles down in just a few seconds. However, the real magic is in the mechanism that restores the marbles from the bottom of the run all the way back to the top.

A motor turns a gear, which then rotates a crank leading to a multi-link rhombus. On one corner of the rhombus is a small protrusion with a magnet attached, which picks up the marbles from the bottom of the run. As the mechanism turns, the rhombus shifts and brings the marble-carrying arm to the top of the marble run. There, it’s grabbed by another magnet, which holds the marble for a moment before letting it drop back down through the run.

It’s a simple project that nonetheless would make a brilliant desk toy. It’s also a great way to learn about linkage analysis and designing such systems on your own. If you’re big into marble runs, you might also consider procedurally generating them. Video after the break.

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Hand-Cranked Doodler Made Using A 3D Printer

September 16, 2022 by 20 Comments

3D printers are great at creating complex geometry out of plastic, and that geometry can often pull off some impressive tricks. [DaveMakesStuff] found a way to generate geometry that draws 2D shapes with a pen and some fancy cams, and it’s really fun to watch.

The build is relatively simple. It consists of a frame which holds a 3D-printed cam turned by a hand crank. That cam controls the movement of a pen in two dimensions, letting it draw all manner of shapes. Videos on Reddit demonstrate it drawing squares, figure eights, and stars, while on YouTube, it writes the phrase “CAM I AM.”

According to [DaveMakesStuff], he figured out how to create the cams with “hours and hours of tedious CAD work.” We imagine there’s a way to do this with maths instead in parametric modelling software, and await such a build on the Hackaday tipsline. Those eager to recreate the build can explore the files on Thingiverse.

We’ve seen some great 3D-printed mechanisms before, too, like this zig-zag cam for a sewing machine. Video after the break.

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