A Mobius keyboard surrounded by the parts to make a Mobius keyboard.

Mobius Keyboard Wastes Little Space

October 3, 2024 by Kristina Panos 25 Comments

What is with all the wasted space on keyboards? There’s a whole back side just sitting there doing nothing. But how can you use the back at the same time as the front?

How to properly wire the boards together. — All the board sandwiches must be wired together like this, natch.

Just when we think Google Japan can’t possibly produce another weird, amazing keyboard that actually works and comes with full documentation, they go and outdo themselves with this ortholinear Mobius thing that wastes (almost) no space. (Japanese, translated) Be sure to check out the video after the break where hilarity ensues.

This crazy thing is made up of 26 modules, each with 8 key switches, four on a side. Do the math — that’s a total of 208 keys! More than enough to stretch out around the table and do some group programming without rubbing elbows. All the switches are hot-swappable, and there’s even RGB backlighting. The controller here is the STM32F042F4P6.

So what are all the extra keys for? Well, the keyboard is half in Japanese and half QWERTY, and has a set of emoji keys as well for the full programming experience. You can also make a paper version if you want to test out the topology.

Be sure to check out the documentation, because it’s pretty interesting how this keyboard is put together. And no, we’re not sure how to set it down and use it without accidental key presses. Suppose that’s part of the charm?

Have you ever wondered what happened to all the Japanese computers of yore? We did.

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Möbius String Robot Goes Round And Round

May 19, 2024 by Al Williams 9 Comments

While it doesn’t look like a traditional robot, the hydrogel robot from [Zi Liang Wu] forms a möbius strip and can be activated by light. They also experimented with shaping the hydrogels as a Seifert ribbon.

The key is that the hydrogels contain gold nanoparticles. Light heats the gold particles and this causes the hydrogels to move. The connections between the strips of hydrogels causes them to move in predictable ways. You can see a video about the experiments below.

These robots aren’t going to be for warehouse or factory work. But they can do tasks like collecting plastic beads, something difficult for conventional robots to do. They also hope to demonstrate that these soft robots could work in the body for taking samples or delivering a drug, although it isn’t apparent how light would get to them inside your body.

The dark side of the material tends to turn towards the light. The continuous loop structure means it never runs to the end of its travel. Watching it move on a string is pretty impressive.

Crawling and slithering robots may be the answer for certain specialized applications. After all, it works well in nature.

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Möbius Tank’s Twisty Treads Became Bendy

January 14, 2024 by Donald Papp 14 Comments

[James Bruton]’s unusual Möbius Tank has gotten a little more unusual with the ability to bend itself, which allows it to perform turns even though it is a single-track vehicle.

The turning radius isn’t great, but three-point turns are perfectly feasible.

The Möbius Tank was a wild idea that started as a “what if” question: what if a tank tread was a Möbius strip? We saw how [James] showed it could be done, and he demonstrated smart design and assembly techniques in the process.

He’s since modified the design to a single-track, and added a flex point in the center of the body. Two linear actuators work together to make the vehicle bend, and therefore give it the ability to steer and turn. A normal tread would be unable to bend in this way, but the twist in the Möbius tread accommodates this pivot point perfectly well.

It works, but it’s not exactly an ideal vehicle. With the tread doing a 90-degree twist on the bottom, there isn’t a lot of ground clearance. In addition, since the long vehicle has only a single tread, it is much taller than it is wide. Neither does it any real favors when it comes to stability over uneven terrain, but it’s sure neat to try.

Even if it’s not practical, Möbius Tank is wild to look at. Check it out in the video, embedded just under the page break.

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Behold The Track-Twisting Möbius Tank

November 18, 2023 by Donald Papp 17 Comments

It started with someone asking [James Bruton] about using a Möbius strip as a tank tread. He wasn’t sure what the point would be, but he was willing to make one and see what happened. Turns out it works reasonably well!

The grey plates are responsible for tensioning the tracks. Designing them as separate pieces means rework for fine-tuning avoids having to re-print structural parts.

The main design challenge was creating a tread system that would allow for the required rotation. [James] designed in the ability for each link to rotate about 18 degrees, and ensured plenty of open space on the upper side of the drive train to accommodate a full 180 degree twist. It took a little fine-tuning and looks a bit trippy, but in the end works about as well as a regular tread system.

[James] shows off a good technique to keep in mind when constructing big assemblies like this tank. It takes a lot of time and material to print large pieces, and in such cases it’s especially important to minimize rework. [James] therefore designs smaller, separate pieces as interfaces to other parts. This way, if changes are needed down the line (for example, to adjust motor placement or change tension on parts), only a smaller interface piece needs to be redone instead of having to re-print a huge part.

The unit uses an Arduino Mega, two 24 V gearmotors to drive each tread independently, an RC radio receiver, and some beefy BTS7960 DC motor drivers to drive the motors.

[James]’ unit is pretty big, but we’ve also seen 3D printed tanks capable of carrying a human driver. It’s clear that build plate size doesn’t seem to limit tank designs. Watch the Möbius tank get built and drive around in the video, just below the page break.

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3D-Printed Mobius Strip Of Gears

May 11, 2019 by Lewin Day 12 Comments

Exploring the mathematics behind everyone’s favourite unorientable single-sided surface can be quite the mind-bending exercise, so it’s nice that it’s so easy to make a Mobius strip out of paper and a single piece of tape. That demonstration was far from enough for [elmins]. who printed this Mobius strip of gears. The teeth fit together, and all the gears move, but there is still only one side and one edge (we think).

This animation helped spawn the project.

The idea to tackle the project came from seeing an animation of Mobius gears. Wondering if it would be possible to actually create such a thing, [elmins] got to work. The design is printed in 60 pieces, 30 each for the inner and outer parts. The entire assembly is printed in PETG, an unconventional choice but by no means unsuitable. 285 ball bearings help the rings rotate.

The gears use a standard involute bevel profile, though [elmins] suspects this could be an area of further optimisation. The parts were printed in an orientation to ensure the print lines run around the races, allowing for minimal finishing and smooth rolling of the bearings. This is a good study of just what can be achieved with some smart modelling and perseverance.

If you’re thirsty for more madcap machining, consider exploring the concept of the Reuleaux triangle bearing.