The supersonic trebuchet being modeled in software

Supersonic Projectile Exceeds Engineers Dreams: The Supersonic Trebuchet

December 1, 2021 by Ryan Flowers 62 Comments

Have you ever sat down and thought “I wonder if a trebuchet could launch a projectile at supersonic speeds?” Neither have we. That’s what separates [David Eade] from the rest of us. He didn’t just ask the question, he answered it! And he documented the entire build in a YouTube video which you can see below the break.

The trebuchet is a type of catapult that was popular for use as a siege engine before gunpowder became a thing. Trebuchets use a long arm to throw projectiles farther than traditional catapults. The focus has typically been on increasing throwing distance for the size of the projectile, or vice versa. But of course you’re here to read about the other thing that trebuchets can be used for: speed.

How fast is fast? How about a whip-cracking, sonic-booming speed in excess of 450 meters per second! How’d he do it? Mostly wood and rubber with some metal bits thrown in for safety’s sake. [David]’s video explains in full all of the engineering that went into his trebuchet, and it’s a lot less than you’d think. There’s a very satisfying montage of full power trebuchet launches that make it audibly clear that the projectile being thrown is going well past the speed of sound, with a report quite similar to that of a small rifle.

[David]’s impressive project and presentation makes it clear that all one has to do to build a supersonic trebuchet is to try. Just be careful, and watch where you shoot that thing before you put somebody’s eye out, ok?

Speaking of things that can go unexpectedly fast, check out these unpowered RC gliders that approach the speed of sound just feet off the ground. And thanks to [Keith] for the awesome Tip!

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This Old Mouse: Building A USB Adapter For A Vintage Depraz Mouse

August 9, 2021 by Ryan Flowers 14 Comments

When [John Floren] obtained a vintage Depraz mouse, he started out being content to just have such a great piece of history in his possession. But if you’re like him, you know it’s not enough to just have something. What would it be like to use it?

To find out, [John] embarked on a mission to build a USB adapter for his not so new peripheral.
Originally used in very early terminals with a Unix GUI, the Depraz mouse utilizes an unusual male DE9 connector rather than the more familiar female DB9 used in RS232 serial mice. Further deviating from the norm, he found that the quadrature encoders were connected directly to the DE9 connector.

Armed with an Arduino Pro ~~Mini~~ Micro and some buggy sample code, he got to work. The aforementioned buggy code was scrapped and a fresh sketch for the Arduino Pro ~~Mini~~ Micro gave the Depraz mouse the USB interface it lacked. [John] also found that he wasn’t the first hardware hacker to have modified the mouse for their use. Be sure to read to the end the article to find out about the vintage surprise lurking in the mouse shell itself! A demonstration of the mouse in action can be seen in the video below the break.

Looking for a fun mouse hack? Perhaps you’d like to use your more modern USB mouse on a retro computer, or try your hand at recreating an early Apple mouse for use in modern computers.

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The Trials Of Digital Design Class

April 2, 2012 by Brian Benchoff 28 Comments

Late last week, we saw a rather clever combination lock build that used only a single 74xx logic chip. [J. Peterson] read this post, and in a battle royale of geek one upmanship sent us a write up of the logic chip computer he built nearly 30 years ago at the University of Utah.

Around 1982 or 1983, [J. Peterson] took the Digital Hardware Lab at the University of Utah. The class was split into two semesters; during the fall semester, students would build a four digit, stack-based calculator that could add and subtract. That may sound easy, but everything – including reading the keyboard, multiplexing LEDs, and performing the mathematical operations – was done with gates and latches.

After Christmas break, the poor souls who had just finished their calculator were presented with another challenge due in four short months. The calculator built during the fall would turn into a full-blown computer, functionally similar to a PDP-8.

After months of work, and seeing the 70 people who showed up on the first day of class in September dwindle down to a handful in late April, [J. Peterson]’s computer was complete. The test program ran through a couple iterations, and the computer was immediately disassembled.

An awesome tale of digital design from only a generation ago. And you thought Verilog was hard.

Getting A Home Built Scanner From ’92 Up And Running Again

March 19, 2012 by Brian Benchoff 8 Comments

In 1992, [Arpi] didn’t have much time for Ninja Turtles, Nintendos, and other wonderful wastes of time his fellow geeks were raised on. He was busy building a scanner for his Commodore 64. Although this very impressive build could have been lost to the sands of time, he pulled his project out of the attic for a “Try to use it again” party. Although this party is not a formal competition, we’re going to say that [Arpi] walked home that night with the most geek cred.

While there are no build details, there is a bunch of info to be gleaned from the gallery about how this machine was built. We’re pretty sure a good majority of the build was a typewriter at one point, and it looks like there’s a windshield wiper motor in there somewhere. Like this completely unrelated but similar build, [Arpi]’s scanner uses a photoresistor and a few LEDs to transfer image data to the custom software. In case you were wondering, yes, the ancient 5 1/4 floppy disk was still readable – one of the few advantages of the huge sectors on these disks.

Check out the videos of this scanner in action after the break, and if you’ve got a decades-old hack sitting in your attic (remember that acoustic modem you built?), send it in on the tip line.

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Playstation 3 Boomerang Controller

September 12, 2008 by Eliot 11 Comments

Reader [HotDog-Cart] is an active member of the benheck forums and recently completed this Playstation 3 boomerang controller. The boomerang was originally shown with the Playstation 3 prototype and was severely panned by the press. [Josh] started with a cheap 3rd party controller that was approximately boomerang shaped. He enlarged the controller body ~20% using bondo. The internals were replaced with gear from an official Sony controller. It was finished with a coat of black paint. It’s definitely a nice build and the new internals mean it probably feels as good as any factory controller.