LEGO Race Car Simulator Is Like A Mechanical Arcade Game

November 14, 2022 by 6 Comments

We’ve all played some variant of that simple old racing video game. It’s the one that involves swerving around cars in front without crashing, as the pace steadily increases further. [Dr. Engine] has recreated that very game in the physical world, with the help of LEGO Technic.

The design uses what appears to be a LEGO tank tread to create a treadmill for a LEGO car. The initial design is hand-cranked, but [Dr. Engine] soon upgrades this with a motor. The wide treadmill is then fitted with a steering wheel. This steers the car laterally along the treadmill via a simple pulley system. From there, it was a simple job of adding gearbox to change the speed of the treadmill, and obstacles for the car to dodge. Double-sided table affixed small die-cast cars to the track to fit the theme of the build.

It’s great fun watching the car buck and weave over the undulating track, and we’d certainly love to compete with friends for the high score. We’ve seen similar builds before, too, like this all-LEGO suspension dyno. Video after the break.

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Play DOOM On Seven-Segment Displays

October 29, 2022 by 12 Comments

Getting DOOM to run on a computer it was never meant to run on is a fun trope in the world of esoteric retro computers. By now we’ve seen it run on everything from old NES systems to microwaves, treadmills, and basically anything with a computer inside of it. What we don’t often see are the displays themselves being set up specifically to run the classic shooter. This build might run the game itself on ordinary hardware, but the impressive part is that it’s able to be displayed on this seven-segment display.

This build makes extensive use of multiplexers to drive enough seven-segment displays to use as a passable screen. There are 1152 seven segment digits arranged in a 48 by 24 array, powered by a network of daisy-chained MAX7219 chips. A Python script running on a Raspberry Pi correlates actual image data with the digit to be displayed on each of the segments, and the Raspberry Pi sends all of that information out to the screen. The final result is a display that’s fast enough and accurate enough to play DOOM in a truly unique way.

There is much more information available about this project on their project page, and they have made everything open source for those who wish to follow along as well. The project includes more than just the ability to play DOOM, too. There’s a built-in video player and a few arcade programs programmed specifically to make use of this display. Perhaps one day we will also see something like this ported to sixteen-segment displays instead of the more common seven-segment.

Gym Equipment Converted To Generator

June 29, 2022 by 41 Comments

Energy cannot be created or destroyed, but the most likely eventual conclusion of changing it from one form or another will be relatively useless heat. For those that workout with certain gym equipment, the change from chemical energy to heat is direct and completely wasted for anything other than keeping in shape. [Oliver] wanted to add a step in the middle to recover some of this energy, though, and built some gym equipment with a built-in generator.

Right now he has started with the obvious exercise bike stand, which lends itself to being converted to a generator quite easily. It already had a fairly rudimentary motor-like apparatus in it in order to provide mechanical resistance, so at first glance it seems like simply adding some wires in the right spots would net some energy output. This didn’t turn out to be quite so easy, but after a couple of attempts [Oliver] was able to get a trickle of energy out to charge a phone, and with some more in-depth tinkering on the motor he finally was able to get a more usable amount of energy to even charge a laptop.

He estimates around 30 watts of power can be produced with this setup, which is not bad for a motor that was never designed for anything other than mechanical resistance. We look forward to seeing some other equipment converted to produce energy too, like a rowing machine or treadmill. Or, maybe take a different route and tie the exercise equipment into the Internet connection instead.

Retrotechtacular: Clay Pipe The Hard Way

May 31, 2022 by 28 Comments

Troll YouTube long enough and chances are good that you’ll come across all kinds of videos of the “How It’s Made” genre. And buried in with the frying pans and treadmills and dental floss manufacturers, there no doubt will be deep dives on how pipe is made. Methods will vary by material, but copper, PVC, cast iron, or even concrete, what the pipe factories will all have in common is the high degree of automation they employ. With a commodity item like pipe, it’s hard to differentiate yourself from another manufacturer on features, so price is about the only way to compete. That means cutting costs to the bone, and that means getting rid of as many employees as possible.

Such was not always the case, of course, as this look at how Irish Stoneware & Fireclays Ltd. made clay pipe, drain tiles, and chimney flues back in the 1980s shows. The amount of handwork involved in making a single, simple piece of clay pipe is astonishing, as is the number of hands employed at the various tasks. The factory was located in Carrickmacross, County Monaghan, Ireland, near an outcropping of shale that forms the raw material for its products. Quarrying the shale and milling it into clay were among the few mechanized steps in the process; although the extrusion of the pipe itself was also mechanized, the machines required teams of workers to load and unload them.

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Human Power, Past And Future

March 1, 2022 by 54 Comments

We will assume you’ve seen The Matrix — it was from 1999, after all. The surprise, at the end, was that humans were being used as human batteries to power a civilization of intelligent machines. But aside from just putting out some heat, the idea does have some precedent. After all, humans powered machines like mills, sewing machines, and pumps for centuries before there were good alternatives.

History

Galley ship
Reconstruction of a squadron of ancient Greek galley ships.

Early machines used hand cranks, treadwheels, treadles, and even pedal power to harness energy from humans. Consider, for example, an ancient galley ship with many oarsmen providing an engine. This wasn’t a great use of human power. An oarsman on a galley used his arms and back but didn’t much use his legs. The legs, though, have larger muscles and are often stronger. A pedal boat or racing shell would have been much more efficient, but without mass production of strong metal parts, it would have been difficult to build and maintain such machines in ancient times.

There was a time when pedals or treadles operated lots of machines from sewing machines to lathes. There were even old radios able to transmit and receive with no external power thanks to pedals as late as the 1940s.

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Portable VO2 max measurment mask

Printable Portable Mask Gives You The Numbers On Your Workout

January 16, 2022 by 7 Comments

We’re currently in the midst of New Year’s Resolutions season, which means an abundance of spanking new treadmills and exercise bikes. And one thing becomes quickly obvious while using those machines: the instruments on them are, at best, only approximately useful for measuring things like your pulse rate, and in the case of estimating the calories burned by your workout, are sometimes wildly optimistic.

If precision quantification of your workout is your goal, you’ll need to monitor your “VO2 max”, a task for which this portable, printable mask is specifically designed. This is [Robert Werner]’s second stab at a design that senses both pressure differential and O2 concentration to calculate the maximum rate of oxygen usage during exercise. This one uses a commercially available respirator, of the kind used for painting or pesticide application, as the foundation for the build. The respirator’s filter elements are removed from the inlets to provide free flow of air into the mask, while a 3D printed venturi tube is fitted to its exhaust port. The tube houses the pressure and O2 sensors, as well as a LiPo battery pack and an ESP32. The microcontroller infers the volume of exhaled air from the pressure difference, measures its O2 content, and calculates the VO2 max, which is sent via Bluetooth to a smartphone running an exercise tracking app like Zwift or Strava.

[Robert] reports that his $100 instrument compares quite well to VO2 max measurements taken with a $10,000 physiology lab setup, which is pretty impressive. The nice thing about the design of this mask is how portable it is, and how you can take your exercise routine out into the world — especially handy if your fancy exercise bike gets bricked.

Rat playing DOOM

Rats Learn To Play DOOM In This Automated VR Arena

December 29, 2021 by 29 Comments

When we run an article with “DOOM” in the title, it’s typically another example of getting the venerable game running on some minimalist platform. This DOOM-based VR rig for rats, though, is less about hacking DOOM, and more about hacking the rats.

What started as a side project for [Viktor Tóth] has evolved into quite a complex apparatus. At the center of the rig is an omnidirectional treadmill comprised of a polystyrene ball about the size of a bowling ball. The ball is free to rotate, with sensors detecting rotation in two axes — it’s basically a big electromechanical mouse upside down. The rat rides at the top of the ball, wearing a harness to keep it from slipping off. A large curved monitor sits right in front of the rat to display the virtual environment, which is a custom DOOM map.

With the VR rig built, [Viktor] worked on automating the training. A treat dispenser provides the proper motivation, while powered drive wheels engage with the ball to nudge the rat if it gets stuck in the virtual world. [Viktor] says he has trained three rats — [Romero], [Carmack], and [Tom] — to walk down a straight hallway using this automated method. As for the meat of the game — shooting monsters — [Viktor] has that covered too, with a sensor that detects when a rat rears up on its hind legs to register a shot.

Total training time to get the rats to the point seen in the video was about six weeks, and [Viktor] reports the whole thing cost him about $2000. That’s a lot of time and money, but the results are pretty interesting. If you’re more interested in minimalist DOOM builds, we understand — check out DOOM on a lightbulb, or a thermostat, or even a GPS.

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