Gyroscope Walks The Tightrope

May 23, 2023 by 13 Comments

Gyroscopes are one of those physics phenomena that are a means to many ends, but can also enjoyed as a fascinating object in their own right. Case and point being [Hyperspace Pirate]’s tightrope-balancing crawler in the video after the break.

Inside the PLA and aluminum shell is a 3D-printed wheel with steel bolts around the edge for added moment of inertia. It is powered by a low-KV brushless motor with a 3:1 GT2 belt-drive and controlled by a simple servo tester, running on a 4 cell LiPo battery. The 3D-printed drive wheel is powered by a geared DC motor hooked directly to the battery. [Hyperspace Pirate] goes over the math of the design, showing that path to stability is a high speed and high moment of inertia flywheel, while staying well within the strength limits of the wheel’s material.

It’s balancing act was first demonstrated on a length of PVC conduit and then on a section of rope, with the characteristic circular wobbling of a gyroscope, known as gyroscopic precession. Without active correction, this the angle of procession will steadily increase until the machine falls over. Even so, it’s still great to watch a small scale version, like the one that inspired this build, would make a pretty cool desk toy.

Gyroscopes are commonly used in attitude indicators and and heading indicators in aircraft, and we’ve also seen them get used for balancing robots. Any ideas for practical uses for a mono-wheel rail/rope walker? Drop them in the comments below.

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Handle Sheet Metal With The Power Of Microwave Oven Electromagnets

May 23, 2023 by 17 Comments

For those of us who don’t do it every day, handling sheet metal can be a nerve-wracking affair. Sheet metal is thin, heavy, and sharp, and one wrong move while handling it can have much the same result as other such objects, like guillotine blades. If only there was a way to lessen the danger.

Perhaps something like this electromagnetic sheet metal handler by [Lucas] over at “Cranktown City” would be useful in keeping one’s fingers and toes attached. Like many interesting builds, this one starts with the dismemberment of a couple of old microwave ovens, to liberate their transformers. Further dissection resulted in open-frame electromagnets, which when energized with a battery from a Ryobi cordless tool do a fine job sticking to stuff.

[Lucas] then harvested the battery connector from the cheapest possible Ryobi tool — an electric fan — and built a prototype, which worked well enough to proceed to a more polished version two. This one had the same guts in a nicely designed case, 3D-printed from lime green filament for that OEM look. The video below shows the design and build, as well as field testing. We have to say this gave us a bit of pause, especially when the battery popped out of one of the handlers and sent the sheet on a near-miss of [Lucas]’ toes. Close call there.

If you’re thinking that you’ve seen MOTs repurposed as electromagnets before, you’re right. Whether climbing like [Spider-Man], lifting heavy steel beams, or walking upside down, microwave oven transformers are the key.

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A blue work tricycle (single front wheel with platform between two rear wheels) sits on an asphalt path with trees and wildflowers in the background. A boxy, white camper with a front overhanging the bike seat is attached to the platform. It has a yellow stripe and curtains like many campers did in the 1970s. One white male is exiting the door of the camper while his brother is standing to the left of the camper by the bike seat.

Bike Camper With Retro Flair

May 23, 2023 by 33 Comments

As we’re approaching summer here in the Northern Hemisphere, thoughts naturally turn toward road trips. While most people do this in their car, the [Dangie Bros] built a 500 lb bike camper for their own take on the great American Road Trip.

Taking a maximalist approach not seen in most bike campers, this behemoth has a working sink, propane stove, seating area, and an upstairs sleeping area. A small window in the front of the camper opens to let the passenger inside converse with the person pedaling, and a solar panel charges a small battery for lights and a roof fan.

While the camper is very ’70s retro-chic, its lack of assist (other than the passenger getting out to push) meant that on the second day of their road trip they resorted to towing the camper behind a second bike in a pseudo-tandem arrangement. The fold out bed takes some design cues from RVs, but clearly needed more reinforcement since it collapsed partway through the night. With an e-assist and some refinements, this could be comfortable (albeit slow) way to go bike glamping.

If you’d like to try your own hand at a bike camper but do it more aerodynamically and attached to an assisted bike, checkout this teardrop trailer or this bike camper.

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Remote-Controlled Hypercar Slices Through Air

May 23, 2023 by 17 Comments

Almost all entry-level physics courses, and even some well into a degree program, will have the student make some assumptions in order to avoid some complex topics later on. Most commonly this is something to the effect of “ignore the effects of wind resistance” which can make an otherwise simple question in math several orders of magnitude more difficult. At some point, though, wind resistance can’t be ignored any more like when building this remote-controlled car designed for extremely high speeds.

[Indeterminate Design] has been working on this project for a while now, and it’s quite a bit beyond the design of most other RC cars we’ve seen before. The design took into account extreme aerodynamics to help the car generate not only the downforce needed to keep the tires in contact with the ground, but to keep the car stable in high-speed turns thanks to its custom 3D printed body. There is a suite of high-speed sensors on board as well which help control the vehicle including four-wheel independent torque vectoring, allowing for precise control of each wheel. During initial tests the car has demonstrated its ability to  corner at 2.6 lateral G, a 250% increase in corning speed over the same car without the aid of aerodynamics.

We’ve linked the playlist to the entire build log above, but be sure to take a look at the video linked after the break which goes into detail about the car’s aerodynamic design specifically. [Indeterminate Design] notes that it’s still very early in the car’s development, but has already exceeded the original expectations for the build. There are also some scaled-up vehicles capable of transporting people which have gone to extremes in aerodynamic design to take a look at as well.

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Supercon 2022: Nick Poole Makes A Jolly Wrencher Tube

May 23, 2023 by 5 Comments

[Nick Poole] shared his circuitous journey into the obscure world of homemade vacuum tubes on the Supercon 2022 stage. It began innocently enough when he saw [Usagi Electric]’s single bit computer vacuum tube computer, which uses dozens of vacuum tubes. He got to wondering, could you make vacuum-tube-like devices containing multiple elements? There are some examples, like the 256-bit memory Selectron tube from the 1950’s, but nothing general purpose like a 555 timer or quad NAND gate packages. Unencumbered by a deep understanding of how vacuum tubes work, [Nick] proceeds to fill this void by imagining Integrated Thermionic, a fictitious company that exists in an alternate history where transistors were not invented and the vacuum tube reigns supreme. He also showcases a variety of innovative products that Integrated Thermionics manufactured over the decades, including surface mount tubes.

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Building Circuits Flexibly

May 23, 2023 by 20 Comments

You think of breadboards as being a flexible way to build things — one can easily add components and wires and also rip them up. But MIT researchers want to introduce an actual flexible breadboard called FlexBoard. The system is like a traditional breadboard, but it is literally flexible. If you want to affix your prototype to a glove or a ball, good luck with a traditional breadboard. FlexBoard makes it easy. You can see a short video below and a second video presentation about the system, also.

The breadboard uses a plastic living hinge arrangement and otherwise looks more or less like a conventional breadboard. We can think of about a dozen projects this would make easier.

What’s more, it doesn’t seem like it would be that hard to fabricate using a 3D printer and some sacrificial breadboards. The paper reveals that the structures were printed on an Ender 3 using ePLA and a flexible vinyl or nylon filament. Want to try it yourself? You can!

We know what we will be printing this weekend. If you make any cool prototypes with this, be sure to let us know. Sometimes we breadboard virtually. Our favorite breadboards, though, have more than just the breadboard on them.

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Smart Pants Sound Alarm When Your Fly Is Undone

May 23, 2023 by 28 Comments

It’s always embarrassing to be told your fly is down. Even moreso when you realize it’s been that way since you returned from the bathroom an hour ago. [Guy Dupont] has built a device to solve this awkward issue once and for all. (Nitter)

Pictured: The Hall effect sensor and magnet attached to the zipper.

The pants contain a Hall effect sensor which has been attached inside the fly of the jeans, at the bottom of the zipper. The zipper pull itself was then fitted with a strong magnet, which triggers the sensor when the zipper is in the open position. An ESP32 in the pocket of the jeans is tasked with monitoring the sensor. If it detects that the zipper has been down for too long, it sends a notification to the wearer’s smartphone to zip up. We kind of wish they’d sound an ear-splitting klaxon, but that might draw undesired attention to the wearer.

Zipper position monitoring seems like a nightmare at first, but [Guy]’s hack shows us that it’s actually trivial with this method. The system does, however, add significant complication to what was previously a totally-analog pair of pants. Don’t expect “Big Jeans” to jump on this tech, as maintenance and waterproofing issues would likely make the hardware a pain to deal with in real life.

Plus, just imagine the frustration every morning. “Sorry, mate, not ready to head out yet – I’ve gotta pair my jeans with my smartphone.”

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