CNC Scroll Saw Makes Promising First Cuts

June 4, 2020 by 40 Comments

When we talk about CNC machines, we almost invariably mean a computer controlled router. Naturally you can do other forms of automated cutting, say using a laser or a water jet, but what about adding computer control to other types of saws? [Andrew Consroe] recently put together a postmortem video about this experimental CNC scroll saw. While he never quite got it working reliably, we think his approach is absolutely fascinating and hope this isn’t the last we see of the idea.

Those who’ve used a scroll saw in the past might immediately see the challenge of this build: while a router bit or laser beam can cut in any direction, a scroll saw blade can only cut in one. If you tried to make a sharp turn on a scroll saw, you’ll just snap the fragile blade right off. To work around this limitation, [Andrew] came up with the brilliant rotary table that can be seen in the video after the break.

By combining motion of the gantry with table rotation, he’s able to keep the blade from ever making too tight a turn. Or at least, that’s the theory. While the machine works well enough with a marker mounted in place of the blade, [Andrew] says he never got it to the point it could reliably make cuts. It sounds like positioning errors would compound until the machine ended up moving the work piece in such a way that would snap the blade. Still, the concept definitely works; towards the end of the video he shows off a couple of pieces that were successfully cut on his machine before it threw the blade.

While we’ve actually seen DIY scroll saws in the past, this is the first computer controlled one to ever grace the pages of Hackaday. While some will no doubt argue that there’s no sense building one of these now that laser cutters have reached affordable prices, we absolutely love this design and how much thought went into it. At the very least, we figure this it the beefiest doodle-drawing robot ever constructed. Continue reading “CNC Scroll Saw Makes Promising First Cuts” →

Hackaday Prize And UCPLA Are Driving Assistive Technology Forward

June 3, 2020 by 1 Comment

Take a second to imagine all the people in your life. Your family, friends, coworkers. Your buddies down at the hackerspace, and anyone you chat with on IO and over the airwaves. Statistically speaking, one in four of these people has a disability of some kind, and needs help doing everyday things that you might not think twice about — simple things like opening doors or interacting with computers. Or maybe that one in four is you.

For the past 75 years, United Cerebral Palsy of LA (UCPLA) have been helping people with various developmental and intellectual disabilities to live independently with dignity. They work directly with members of the disabled community to develop assistive technology that is both affordable and dependable. UCPLA helps the disabled community with everything from employment to providing a creative outlet, and gives them the tools to do these things and more. Their mission is to help people be as independent as possible so they can feel good about themselves and enjoy a life without limits.

The people behind this non-profit are all about inclusion, access, and opportunity, and this is why we are proud to partner with UCPLA for the 2020 Hackaday Prize. With the world in upheaval, there is no better time to build a better future for everyone. You never know when you might need assistive technology. In addition to the open challenge that calls for everyone to work on a design, this year there is also a Dream Team challenge which offers a $3,000 per month stipend over the next two months to work on a team addressing one specific challenge. Apply for that asap!

What kind of challenges has UCPLA outlined for the Hackaday Prize? Let’s dive in and find out, and we’ll also hear from the UCPLA team in a Q&A video at the end of the article.

Continue reading “Hackaday Prize And UCPLA Are Driving Assistive Technology Forward” →

Dual-Wielding Robot Carves 3D Shapes From Foam With Warped Wire

June 3, 2020 by 28 Comments

“Every block of expanded polystyrene foam has a statue inside it and it is the task of the dual-arm hot wire-wielding robot to discover it.” — [Michelangelo], probably.

Be prepared to have your mind blown by this dual-wielding hot-wire 3D foam cutter (PDF). We’ve all seen simple hot-wire cutters before, whether they be manual-feed cutters or CNC-controlled like a 3D-printer. The idea is to pass current through a wire to heat it up just enough to melt a path as it’s guided through a block of polystyrene foam. Compared to cutting with a knife or a saw, hot-wire cuts are smooth as silk and produces mercifully little of that styrofoam detritus that gets all over your workspace.

But hot-wire cutters can’t do much other than to make straight cuts, since the wire must be kept taut. “RoboCut”, though, as [Simon Duenser] and his colleagues at ETH Zurich call their creation, suffers from no such limitations. Using an ABB YuMi, a dual-arm collaborative robot, they devised a method of making controlled curved cuts through foam by using a 1-mm thick deformable rod rather than a limp and floppy wire for the cutting tool. The robot has seven degrees of freedom on each arm, and there’s only so much the rod can deform before being permanently damaged, so the kinematics involved are far from trivial. Each pass through the foam is calculated to remove as much material as possible, and multiple passes are needed to creep up on the final design.

The video below shows the mesmerizing sweeps needed to release the Stanford bunny trapped within the foam, as well as other common 3D test models. We’re not sure it’s something easily recreated by the home-gamer, but it sure is fun to watch.

Continue reading “Dual-Wielding Robot Carves 3D Shapes From Foam With Warped Wire” →

A Home Made Dumper You’d Swear Came From A Factory

June 1, 2020 by 9 Comments

When it comes to YouTube videos, there’s little we like more than some good quality workshop action, watching someone in command of their tools craft a machine from raw materials with an amazing result. It’s something [Workshop From Scratch] delivers with his homemade mini dumper, in which he makes a small dump-truck from scratch with a result that looks as though he’d bought it factory-made from his agricultural supplier.

At its heart is a substantial chassis made from welded together double box section tube, to which he’s bolted a second-hand hydraulic transmission of the type you would find on larger walk-behind groundskeeping machinery. At the back is a front steering axle from a mobility scooter, that pivots on a bearing and wheel hub from a Ford Mondeo to ensure stability on rough ground. There is a platform for the operator to stand on as the little Honda 4-stroke engine moves it around. The bucket is plasma cut and welded, and it’s safe to say that his welding ability exceeds ours.

The result is a machine that looks to be very useful, and dare we admit it, one we wouldn’t mind having a go on. It may not be as powerful as this electric home-built dump truck, but we like it.

Continue reading “A Home Made Dumper You’d Swear Came From A Factory” →

Digitize An Analogue Oscilloscope

May 31, 2020 by 13 Comments

Many of us will possess digital oscilloscopes which offer at an affordable price an array of features once unimaginable on the analogue CRT ‘scopes of yesteryear. But those old analogue beasts were fine pieces of equipment when they were made and remain so today. So how can they find a place in the digital age?

Perhaps [Joseph Eoff] has the answer, because he’s fitted his trusty Telequipment D43 with a camera in a 3D-printed attachment, paired with a piece of cross-platform Python/Qt custom software using OpenCV to identify, digitize, and quantify the traces. The software allows viewing the either the digitized trace or the real trace, and derives measurements of voltage and frequency from them. One limitation is that despite the ‘scope being a dual-trace model, the software only has a single set of cursors to measure one trace at a time. All the code can be had from the GitHub repository, should you wish to experiment with it or extend it.

It’s worth thinking for a minute at what price point a remotely decent digital ‘scope starts, then considering the ease with which surprisingly good older analogue instruments can be found on the second-hand market for not a lot. An approach such as this one makes them an even more attractive proposition.

If you’re looking further into enhancements for an analogue ‘scope, how about a logic analyser?

Cheap Speakers Sound Good With Easy Open Baffle Design

May 29, 2020 by 20 Comments

If you’ve spent any time around audio gear at all, you’ll know that enclosure design is as critical as the speaker drivers themselves. [Frank Olson] demonstrates this ably, with his open baffle design for some cheap off-the-shelf speakers.

[Frank]’s aim was to do a comparison between using no enclosure, and an open baffle design, with a pair of 2″ full-range speakers. These drivers are nothing special; just a low-cost part that you’d find in any cheap set of computer speakers. [Frank] screws the drivers into a thin, flat wooden board, and then adds a supporting strut to allow the speakers to stand on their own.

The comparison makes it clear that even this basic baffle design makes a big difference to perceived sound quality. Bass is fuller, and the sound is far improved thanks to the baffle blocking out of phase sounds from the rear of the speaker.

It’s a technique that could prove useful to anyone quickly trying to rig up an audio setup for the workshop or makerspace out of leftover parts. We’ve featured similar projects before that espouse the benefit of enclosure design when using even very affordable speakers. Video after the break.

Continue reading “Cheap Speakers Sound Good With Easy Open Baffle Design” →

Books You Should Read: The Design Of Everyday Things

May 29, 2020 by 27 Comments

With everything from APIs to Raspberry Pis making it even easier for us to create and share objects shaped by personal whim, it’s high time that Don Norman’s sage design advice falls on not just the design student, but the hardware hacker and DIY enthusiast too. Grab yourself a coffee and a free weekend, and settle into the psychology of people-struggling-how-to-use-that-widget-they-just-purchased in The Design of Everyday Things: Revised and Expanded Edition.

Who’s to blame for a door that opens with a pull when everything about how it looks says it should open with a push? In Don Norman’s world, it’s not you; its the designer. Enter a world where blame is inverted and mistakes can be critically categorized. Norman takes us example by example showing us how common items in the world poorly serve the needs of their user, mainly because the designer simply ignores key aspects of our humanity. This book is a crisp, concise overview of human psychology when applied to engaging with things combined with a language of ideas to help us apply this psychology to better interactions. (And it reads like butter!)

Opening Up to the Language of Design

What’s an affordance, you might ask? Well, simply put, it’s a way that an object can be used by a human. How about a signifier? That’s a communication “signposting” scheme that object uses to suggest to you how it should be used. If that sounds a bit fluffy, just think about the last time you tried to push open a door that needed to be pulled. Something about that door was suggesting that you could push it open, but it couldn’t! It “fooled” you because all the object’s signifiers were telling you otherwise. Continue reading “Books You Should Read: The Design Of Everyday Things” →