Automatically Crack Safes With This Autodialer

March 30, 2025 by Bryan Cockfield 13 Comments

When attempting to secure something, whether it’s a computer, sensitive data, or valuables, there’s always going to be a way to break that security. It might be impossibly hard, like taking centuries to brute-force an encryption algorithm, but it’s weakness is still there. And, like the future might make certain encryption obsolete, modern electronics has made security of the past somewhat obsolete as well. [Startup Chuck] has been using tools the creators of safes from the late 1800s could probably not have imagined.

The tool that [Startup Chuck] has come up with is known as an autodialer in the safe-cracking world, and as its name suggests it automates the process of opening the safe by trying as many combinations as possible. The autodialer attaches to the safe with three magnetic feet and couples to the dial through a chuck attached to a magnetic clutch, which allows the autodialer to disengage as soon as the correct combination is found. It’s driven with a stepper motor which can test out combinations so fast that [Startup Chuck] needed to take 240 fps video and slow it down to make sure that the mechanism was behaving properly.

The autodialer itself can’t actually open the safe, though. The last step of the process is taken care of by a bungie cord, attached to the safe handle to pre-tension it enough so that when the correct combination is finally entered the safe pops open automatically. For anyone looking to duplicate the project, [Startup Chuck] has added the program code to a GitHub page. If you’re looking at a more modern safe, though, there are of course ways to crack their security systems as well.

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Stepper Motor Operating Principle And Microstepping Explained

February 3, 2025 by Maya Posch 14 Comments

The [Denki Otaku] YouTube channel took a look recently at some stepper motors, or ‘stepping motors’ as they’re called in Japanese. Using a 2-phase stepper motor as an example, the stepper motor is taken apart and its components explained. Next a primer on the types and the ways of driving stepper motors is given, providing a decent overview of the basics at the hand of practical examples.

As great as theoretical explanations are, there’s a lot of value in watching the internals of a stepper motor move when its coils are activated in order. Also demonstrated are PWM-controlled stepper motor drivers before diving into the peculiarities of microstepping, whereby the driving of the coils is done such that the stator moves in the smallest possible increments, often through flux levels in these coils. This allows for significantly finer positioning of the output shaft than with wave stepping and similar methods that are highly dependent on the number of phases and coils.

As demonstrated in the video, another major benefit of microstepping is that it creates much smoother movement while moving, but also noted is that servo motors are often what you want instead. This is a topic which we addressed in our recent article on the workings of stepper motors, with particular focus on the 4-phase 28BYJ-48 stepper motor and the disadvantages of steppers versus servos.

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One Small Step: All About Stepper Motors

January 6, 2025 by Maya Posch 12 Comments

The primary feature of stepper motors is listed right within their name: their ability to ‘step’ forwards and backwards, something which they (ideally) can do perfectly in sync with the input provided to their distinct coils. It’s a feature that allows the connected controller to know the exact position of the stepper motor, without the need for any sensor to provide feedback after a movement, saving a lot of hardware and effort in the process.

Naturally, this is the optimal case, and there are a wide number of different stepper motor configurations in terms of coil count, types of rotors and internal wiring of the coils, as well as complications such as skipped steps due to mechanical or driver issues. Despite this, in general stepper motors are quite reliable, and extremely versatile. As a result they can be found just about anywhere where accurate, step-based movement is desirable, such as (3D) printers and robotics.

For each application the right type of stepper motor and driving circuit has to be determined, of course, as they also have many reasons why you’d not want to use them, or just a particular type. When diving into a new stepper motor-based project, exactly what are the considerations to pay attention to?

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Lathe Outfitted With Electronic Gearbox

September 19, 2024 by Bryan Cockfield 45 Comments

Running a metal lathe is not for the faint of heart. Without proper knowledge and preparation, these machines can quickly cause injury or destroy expensive stock, tools, or parts. The other major problem even for those with knowledge and preparedness is that some of their more niche capabilities, like cutting threads with a lead screw, can be tedious and complicated thanks to the change gear system found on some lathes. While these are useful tools for getting things done, [Not An Engineer] decided that there was a better way and got to work building an electronic gearbox to automate the task of the traditional mechanical change gear setup in this video.

What makes change gears so tricky is that they usually come as a set of many gears of different ratios, forcing the lathe operator to figure out the exact combination of gears needed to couple the spindle of the lathe to the feed screw at the precise ratio needed for cutting a specific thread pattern. It is possible to do this task but can be quite a headache. [Not An Engineer] first turned to an Arduino Nano to receive input from a rotary encoder connected to the shaft of the lathe and then instruct a motor to turn the feed screw at a set ratio.

The first major problem was that the Arduino was not nearly fast enough to catch every signal from the encoder, leading to a considerable amount of drift in the output of the motor. That was solved by upgrading to a Teensy 4.1 with a 600 MHz clock speed. There was still one other major hurdle to cross; the problem of controlling the motor smoothly when an odd ratio is selected. [Not An Engineer] used this algorithm to inspire some code, and with that and some custom hardware to attach everything to the lathe he has a working set of electronic change gears that never need to be changed again. And, if you don’t have a lathe at all but are looking to get started with one, you can always build your own from easily-sourced parts.

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A custom LEGO throne for Dune's Baron Harkonnen.

A Throne For LEGO Baron Harkonnen

July 22, 2024 by Kristina Panos 2 Comments

If you’re both a LEGO and a Dune fan, unless you’ve been living in a cave on Mars with your eyes shut and fingers in your ears, you’re probably aware that LEGO released a set for the royal Atreides ornithopter. The blades flap and everything. Anyway, it comes with several minifigures, including one that doesn’t quite fit with the others — a full-length Baron Harkonnen.

Given that, [gorkyver] decided to create a throne for the Baron that he could rise from, just like in the movie, while delivering the iconic line. With no reference materials available other than pausing the movie, [gorkyver] created a throne from scratch in BrickLink Studio, which made it easy to generate both a parts list and step-by-step instructions.

At the heart of this build is an Arduino Nano, which takes input from the momentary push button and starts the show. The Baron slowly rises on a rack and spur gear connected to a stepper motor, and a DF Player Mini runs the audio through a 75 mm speaker.

Rather than just buying a big box store display case off of eBay, [gorkyver] recreated the skeleton in Fusion 360 and used a hairdryer to bend a sheet of PET-G around to enclose it. A couple of sweet adhesive graphics later, and it totally looks like a real set on display. Don’t miss the demo/build video after the break.

Did you hear? The European Space Agency printed some bricks out of meteorite dust, and there might be one on display near you.

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Using The Moiré Effect For Unique Clock Face

June 3, 2024 by Bryan Cockfield 13 Comments

If you’ve ever seen artifacts on a digital picture of a computer monitor, or noticed an unsettling shifting pattern on a TV displaying someone’s clothes which have stripes, you’ve seen what’s called a Moiré pattern where slight differences in striping of two layers create an emergent pattern. They’re not always minor annoyances though; in fact they can be put to use in all kinds of areas from art to anti-counterfeiting measures. [Moritz] decided to put a few together to build one of the more unique clock displays we’ve seen.

The clock itself is made of four separate Moiré patterns. The first displays the hours with a stretching pattern, the second and third display the minutes with a circular pattern, and the seconds are displayed with a a spiral type. The “hands” for the clock are 3D printed with being driven by separate stepper motors with hall effect sensors for calibration so that the precise orientation of the patterns can be made. A pair of Arduinos control the clock with the high-accuracy DS3231 module keeping track of time, and [Moritz] built a light box to house the electronics and provide diffuse illumination to the display.

Moiré patterns can be used for a number of other interesting use cases we’ve seen throughout the years as well. A while back we saw one that helps ships navigate without active animations or moving parts and on a much smaller scale they can also be used for extremely precise calipers.

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Pi Pico Helps Restring Badminton Rackets

May 20, 2024 by Lewin Day 5 Comments

Stringing a badminton racquet is a somewhat complicated job. It needs to be done well if the racquet is to perform well and the player is to succeed. To that end, [kuokuo] built a machine of their own to do that very task. Even better, they’ve made it open source so other hobbyists can benefit from their work.

The build is named PicoBETH, which stands for Pico Badminton Electronic Tension Head. It’s based around the Raspberry Pi Pico, as you might imagine. The Pico is charged with controlling the stringing procedure via a stepper motor and lead screw, while using a load cell to measure string tension during the process. A small two-line character LCD serves as the user interface, along with some buttons, LEDs and a buzzer for feedback. The electronic stringing gear is mounted on to a traditional manual drop-weight stringing machine to execute the process faster and more accurately, at least in theory.

Files are on Github for those that wish to explore the build further. It’s not the first stringing machine we’ve featured here, either! Video after the break.
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