Well, I didn’t mean to take the whole summer off from Keebin’, it just kind of happened that way. You’d think it would have been #13 that tripped me up, but we ain’t even there yet — this is only the twelfth edition. I kept thinking I should write one and it just wasn’t happening, until I got a tip from [s.ol bekic] about their stunning hexagonal keycaps and the journey toward making an open-source 12-key macropad featuring same.
But let’s back up a bit. Originally, [s.ol] designed a totally sick hybrid MIDI-and-typing keyboard from scratch, which you can see in this short video. It glows, it splits in half, and it snaps back together again quite satisfyingly. And you probably noticed the hexagonal keycaps that look like they might be printed or milled, or perhaps even printed and then milled.
In actuality, [s.ol] threw all the processes at this keycap project — milling, molding and casting, and 3D printing. None of them worked well enough to get much past the prototype stage, but in the end, [s.ol] joined forces with fkcaps.com to create and offer an injection-molded version that I’d really, really like to rock my fingertips around in. Good thing I can pick some up for cheap.
Of course, the real process was all the learning [s.ol] did along the way — both in the early days of making the hybrid keyboard, and after teaming up with fkcaps to make the keycaps and the accompanying macropad into real products. And that was after all the design work it took to get this newfangled honeycomb configuration right.
LEGO and its Technic line is a great way to learn about all kinds of mechanical things, but it’s also just a whole lot of fun to play with. We suspect the latter reason is what got [Brick Technology] to pursue creating a trippy water vortex with the building toy.
The first design uses a transparent plastic sphere as a water vessel. Inside the sphere is placed a small turbine, turned from the outside via a magnetic coupling. This means the sphere can remain intact, with no holes required, nor complicated seals which can leak. It works well, and produces a vortex when the turbine is spun by a regular LEGO motor. A second attempt elects to rotate the entire sphere itself. Small LEGO wheels are then used to hold the sphere in place on the rapidly spinning turntable. The results are impressive, creating a large and relatively well-formed vortex.
Naturally, though, the video saves the best for last. The big transparent sphere is installed in a rig that surrounds it completely. The sphere itself is spun up thanks to wheels installed on two different axes. This allows the sphere to be spun in various directions under command from a PlayStation controller, creating more complicated vortexes and flow patterns. A set of swiveling casters are provided to hold the sphere in place as it rotates in various directions, and are damped with springs and rubber bands to stop the rig shaking itself apart.
LEGO trains are fun to play with, but as with any model train, you so seldom have enough track to fulfill your greatest desires. YouTuber [brick_on_the_tracks] has come up with some creative ideas of his own to make track compatible with Lego trains using other techniques.
The most straightforward is to use the LEGO fence piece, first released in 1967. They can be laid in two rows, four studs apart, and they’ll serve as perfectly functional train track. It’s a 100% legal building technique as per the official LEGO rules, too. Official track pieces can be linked up by placing them on a 1-stud-high booster. [brick_on_the_tracks] argues that it’s up to nine times cheaper than using official track, but it depends on how you’re building your layout, and you need to take into account the need for a base plate.
On the sillier side of things, it’s actually possible to use mini-figures as track, too. Again, it’s a 100% legal technique, though the trains don’t run as smoothly compared to the fence track. It’s very amusing, though, and could be a fun addition to a build you’re taking to a local LEGO convention.
If you’re really strapped for cash though, you can go as far as using cardboard. It’s not legal in the LEGO world, and it’s pretty basic, but you could literally make up a layout using nothing but a craft knife and pizza boxes. We’ve actually featured other LEGO train hacks before, like this neat automatic decoupler design.
A submarine is by necessity a complex and safety-critical machine, but the principle upon which it depends is quite simple. The buoyancy is variable by means of pumping water in and out of tanks, allowing the craft to control the depth at which it sits. The [Brick Experiment Channel] has a series of posts describing in detail the construction of a working submarine, with a hull made from a plastic tube and mechanics made from Lego.
In this submarine the buoyancy tank is a syringe operated by a Lego motor, and the propulsion comes courtesy of a pair of Lego motors driven through ingenious magnetic couplings to avoid a shaft seal. To monitor depth there is both a laser distance sensor and a pressure sensor, and there is a Raspberry Pi Zero to control the whole show.
In the video below the break you can see the craft in action as it zips around a swimming pool at different depths, before setting off on a longer journey with on-board footage along a shady creek. It’s an extremely practical submarine, and one we wish we could try.
When it comes to the development and testing of performance suspension, it’s helpful to have a test apparatus that lets you recreate certain conditions reliably. This LEGO suspension dyno does just that, and it’s clearly a big help for those doing R&D on minifig motorcycle suspension.
The build relies on four motors to overcome the resistance of turning a chunky conveyor belt, which acts as a rolling road. As the belt is built out of Technic beams, various LEGO blocks can be added to the conveyor to act as bumps or perturbations for testing suspension.
The video demonstrates the use of the dynamometer, showing how a simple LEGO motorbike design deals with bumps of various sizes. It’s easy to swap out forks and springs and change the geometry to tune the suspension, and the changes can be easily seen when running it through the same test conditions.
While we don’t imagine there are too many people working in this particular field, the lessons being taught here are valuable. This setup allows one to quickly visualize how changing vehicle parameters affects handling. It’s hard to imagine a better teaching tool for vehicle dynamics than something like this that lets you see directly what’s really going on!
In childhood, many of us wondered — wouldn’t it be cool if our miniature toys had “real” functions? Say, that our toy cars actually were able to drive, or at least, that the headlights could light up. [James Brown] captures some of this childhood expectation of magic, recreating the 2×2 45°-sloped Lego bricks with computer screens and panels drawn on them by building a LEGO brick (thread, nitter) with an actual display inside of it.
This is possible thanks to an exceptionally small OLED display and a microcontroller board that’s not much larger. It’s designed to plug onto a LEGO platform that has an internal 9V battery, with power exposed on the brick’s studs. [James] has taken care building this — the brick was built with help of a tiny 3D-printed form, and then, further given shape by casting in what appears to be silicone or resin.
We’ve yet to hear more details like the microcontroller used — at least, the displays look similar to the ones used in a different project of [James]’, a keyboard where every keycap has a display in it (thread, nitter). Nevertheless, it is lovely to witness this feat of micro-engineering and fabrication. It reminds us of an another impressive build we covered recently — a 1/87 scale miniature Smart Car that’s as functional as you can get!
Those old enough to have encountered punch cards in their lifetime are probably glad to be rid of their extremely low data density and the propensity of tall stacks to tip over. But obsolete as they may be, they’re a great tool to show the basics of binary data storage: the bits are easily visible and can even be manipulated with simple tools. As an experiment to re-create those features in a more modern system, [Michael Kohn] made a punch card-like system based on LEGO bricks that stores machine code instructions for a 65C816 CPU, the 16-bit successor to the venerable 6502.
Bits are stored on a white 8×20 stud board, onto which small black pieces are placed. A white background stud encodes a logic “zero”, while a black stud encodes a logic “one”. The bits are read out by an array of reflectance sensors, which conveniently has the same 8 mm pitch as standard LEGO studs. A big wheel driven by a stepper motor slides the data card under the readout circuit along a short stretch of LEGO train tracks.
The optical sensors are read out by an MSP430 series microcontroller, which also drives the motor through a stepper motor driver. Once the data is read out, the bytes are transferred into a WDC W65C265SXB board, which executes them as machine code instructions on its 65C816 CPU. In the video below, you can see a program being loaded that blinks an LED.