Engineering On A Deadline For Squid Game

April 14, 2022 by Adam Fabio 35 Comments

If you asked us for an epic tale of designing and building under a deadline, one of the last places we would think to look is a MrBeast video. Yet here we are, thanks in no small part to the epic skills of one [William Osman].

What do you do when a major YouTube celebrity asks you to handle a project with an impossible deadline? If you’re [William], you say “heck yeah” and figure out the details later. In this case, it was famed YouTuber [Jimmy Donaldson], aka MrBeast, who was planning his own version of Squid Game. In this version, no one dies, but a few players do walk away with a lot of cash.

The premise is simple — “kill” people with a motion-sensing gun turret, just like the one in the show. The problem is that the show had all the tools of movie magic – multiple takes, video editing, you name it. [William] was tasked with handling a live event, with 456 real people, and no do-overs. Oh, and the whole thing had to be ready in 3 weeks.

The kills had to be pretty obvious too – we’re talking simulated blood squirting everywhere. So [William] decided to build his own version of a blood squib – the device Hollywood has used for decades to simulate bullet wounds. Initial work with pneumatic systems proved to be impractical. That’s when he put on his manager hat — and hired people to solve the problem for him. You might recognize a few of them — [Allen Pan] makes an appearance, as well as chemical genius [NileRed]. Even [TheBackYardScientist] shows up.

The video documents [William]’s journey, getting 500 copies of a board built and delivered on deadline. As such, there isn’t a ton of detail about the internal workings of the system. A pair of AA batteries feed into a boost converter, which powers an ESP8266 inside an ESP-WROOM-02 module. The ESP drives a few LEDs and a MOSFET. The MOSFET is connected to the star of the show – an MGJ firewire initiator – think of it as a model rocket igniter on steroids. The initiator hides behind a bag of YouTube-friendly yellow “blood”. When the system is commanded to kill, the initiator pops the bag, spraying blood everywhere.

Doing this for one device isn’t so bad, but we’re following Squid Game rules – which means 456 competitors. Further, there were 100 iPhones loaded with a custom kill app for the workers. Add a central server into the mix, and you’ve got 557 devices in close quarters basting on 2.4 GHz and 5.8 GHz. Did we mention that [William] had never done a test with more than a handful of devices?

Want to find out what happens? Check out the video below!

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Curious Marc Takes On Sewing Machine Repair

November 4, 2021 by Adam Fabio 29 Comments

Even the most talented engineers can be stymied by simple repair projects. In this case, repairing a broken sewing machine has [CuriousMarc] all tangled up. [Marc] is probably best known as a part of the team who managed to restore and boot up an apollo guidance computer, but he’s worked with plenty of other vintage machines.

This problem hit much closer to home. [Marc’s] daughter wanted to sew a Halloween costume. The machine would boot up fine, but when attempting to sew, it would make a bit of noise, then beep and display “The safety device has been activated”. Not very helpful.

The sewing machine in question is called “Baby Lock Decorator’s Choice” and is manufactured by Brother for Juken. [Marc] of course dug in, and quickly found himself stymied by a clamshell case that just didn’t want to come apart. This is the point where many of us would apply just a little too much force when prying and be rewarded with a broken case.

[CuriuosMarc] is thankfully the more patient sort. Rather than become [FuriousMarc], he carefully persevered to find a hidden screw holding things together. The screw could only be accessed by inserting a screwdriver through a tiny access hole on the front chassis of the machine.
With the screw out, a couple of molded clips were all that held the case sides together. After popping them, [Marc] was finally able to fix the real problem: A toothed belt that had slipped off its cog. That’s it — just a loose belt. The cryptic error code most likely was due to the machine realizing it the motor was on, but the machine wasn’t moving – which would generally indicate something stuck or tangled in the thread path.

This type of repair would be much easier if service manuals were readily available. We did a quick search for this model but didn’t find anything freely available.

Have you gotten stuck by a simple repair? Tell us about it down in the comments.

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Janksy Robot Paints Murals One Dot At A Time

November 2, 2021 by Adam Fabio 22 Comments

[Stuff Made Here] has a new shop, with a huge blank wall. A blank white wall just wouldn’t do, so rather than paint the wall himself, he designed a robot to do it for him. (Video, embedded below.)

The result is Janksy. A huge machine made of metal, wood, and 3D printed parts. Janksy is an ingenious design in that it has two sets of X and Y axis. A large, slow-moving system of rails and cables positions the robot roughly in the right area of the wall. From there a much smaller, but faster and more precise motion system makes the final moves.

The “business end” of Janksy is of course a paint sprayer; in this case a Harbor Freight model. The medium of choice is acrylic paint, as Janksy will be painting for several days, and didn’t want to gas himself with the volatile solvents of more traditional paints.

Janksy mainly sprays dots of paint. Up close you’ll only see the dots, but step back a bit and a full image takes shape. It’s a technique called Pointillism, which puts Janksy in the company of artists like Georges Seurat and
Vincent van Gogh.

While human artists mix colors to produce the hue they want, robots can’t easily do that. [Stuff Made Here] spends quite a bit of time explaining basic color theory, and how dots of cyan, magenta, and yellow will combine in the eye to produce colors – much the way a monitor uses pixels of red, green, and blue light.

After all this work, you might be wondering what [Stuff Made Here] would want on his wall. Well, let’s just say that he loves his wife, even though his pranks on here often elicit an exasperated glare. Watch the video after the break for the full story.

You don’t have to build a huge drawing robot though – we’ve seen some great plotters on a much smaller scale, including one that will play tic-tac-toe.

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Fail Of The Week: Alternator Powered Electric Go-Kart Doesn’t Go

October 25, 2021 by Adam Fabio 21 Comments

What do you give a six-year-old who loves going fast but doesn’t like loud noises? Convert a gas go-kart to electric of course! (Video, embedded below.) That goal started [Robert Dunn] of Aging Wheels down a long path toward a go-kart that almost, but doesn’t quite… work.

If you’ve watched any of [Robert’s] videos, you know he doesn’t take the easy path. The man owns a Trabant and Reliant Robin after all. Rather than buy a battery pack, he built his own 5S24P pack from individual LiFePO4 cells. Those cells generally are spot welded, so [Robert] built an Arduino-controlled heirloom-quality spot welder. Now while the welder could handle thin nickel strips, it wasn’t up the task of welding high current nickel-plated copper. When attempts at a solution failed, [Robert] built a system of clamped copper bus bars to handle the high current connections for the batteries.

If batteries weren’t hard enough, [Robert] also decided he wasn’t going to use an off-the-shelf motor for this project. He converted a car alternator to operate as a brushless motor. We’ve covered projects using this sort of conversion before. Our own [Jenny List] even wrote a tutorial on it. [Robert] unfortunately has had no end of trouble with his build.

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Building An Aluminum RC Truck From Scratch

September 5, 2021 by Adam Fabio 14 Comments

These days you can get just about any kind of radio controlled vehicle as a ready-to-run model. Cars, trucks, excavators, you name it. Open the box, charge the batteries, and you’re ready to roll. Even with all these modern conveniences, there is still a special breed of modelers who create their own models using only a few off-the-shelf parts.

[Rini Anita] is exactly that rare breed, creating this aluminum RC truck from scratch. The truck itself is a cab-over — short for Cab Over Engine (COE), a style seen making local deliveries worldwide. He starts with the ladder frame chassis, which is constructed using an extruded aluminum channel. This is the same material you’d normally use for the door tracks in retail store display cases. The electronics and standard RC fare: a receiver, electronic speed control, and a servo for steering. Batteries are recycled lithium cells. The main gearbox and drive axle look to be sourced from another RC vehicle, while leaf springs and suspension components are all custom built.

The truck’s body is a great example hand forming metal. First, a wooden form was created. Sections for the windows and door panels were carved out. Sheet aluminum was then bent over the wood form. Carefully placed hammer blows bend the metal into the carved sections – leaving the imprints of doors, windows, and other panel lines.

Throughout this build, we’re amazed by [Rini]’s skills, and the fact that the entire job was done with basic tools. A grinder, an old drill press, and a rivet gun are the go-to tools; no welder or 3D printer to be found. This puts a project like this well within the means of just about any hacker — though it may take some time to hone your skills! For his next truck, maybe [Rini] can add a self driving option!

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Surgery Robot Is A Real Cut Up

May 7, 2020 by Adam Fabio 23 Comments

A robot that performs surgery is a serious thing. One bug in the control system could end with disaster. Unless of course, you’re [Michael Reeves], in which case disaster is all part of the fun. (Video, embedded below.)

Taking inspiration from The da Vinci Surgical System, [Michael] set out to build a system that was faster, while still maintaining precision. He created a belt drive gantry system, not unlike many 3D printers, laser cutters, or woodworking CNC machines. Machines like this often use stepper motors. [Michael] decided to go with [Oskar Weigl’s] ODrive and brushless motors instead. The ODrive is on open source controller which turns off the shelf brushless motors — such as those found in R/C planes or hoverboards, into precision industrial servos. Sound familiar? ODrive was an entrant in the 2016 Hackaday Prize. [Michael] was even able to do away the ubiquitous limit switch by monitoring current draw with the ODrive.

It all adds up to a serious build. But this is [Michael “laser eye” Reeves] after all. The video is meant to be entertaining, with a hidden payload of education and inspiration. The fun starts when he arms the robot with a giant kitchen knife and performs “surgery” on a pineapple. If you want to know what happens when mannequins and fake blood enter the picture, then watch the video after the break.

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Saving 4 Patients With Just 1 Ventilator

March 19, 2020 by Adam Fabio 59 Comments

We all know that COVID-19 is stressing our health system to the limit. One of the most important machines in this battle is the ventilator. Vents are critical for patients experiencing the worst symptoms of respiratory distress from the virus. Most of the numbers predict that hospitals won’t have enough ventilators to keep up with the needs during the height of the pandemic.

Now anyone with a walkman or iPod can tell you what they do when there is one music device and two people who want to listen: Plug in a Y-connector. Wouldn’t it be great if you could do the same thing with a medical ventilator? It turns out you can – – with some important caveats.

Way back in 2006, [Greg Neyman, MD and Charlene Babcock, MD] connected four simulated patients to a single ventilator. Ventilators connect to a patient with two tubes – an inflow and an exhaust. Using common parts available in just about any hospital, the doctors installed “T-tube” splitters on the inflow and exhaust tubes. They tested this with lung simulators and found that the system worked.

There were some important considerations though. The patients must be medically paralyzed, and have similar lung capacity — you couldn’t mix an adult and a child. The tubing length for each patient needs to be the same as well. The suggestion is to place the patients in a star pattern with the ventilator at the center of the star.

[Dr. Charlene Babcock] explains the whole setup in the video after the break.

Interestingly enough, this technique went from feasibility study to reality during the Las Vegas shooting a few years ago. There were more patients than ventilators, so emergency room doctors employed the technique to keep patients alive while equipment was brought in from outside hospitals. It worked — saving lives on that dark day.

The video and technique remind us of Apollo 13 and the CO2 scrubber modifications. Whatever it takes to keep people alive. We’ve already started looking into open source ventilators, but it’s good to see that medical professionals have been working on this problem for years.

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