[Quinn Dunki] Makes A Screw Shortener Fit For Kings

It’s common problem when you’re building anything with screws: this one is too long, this one is too short. While she can’t teach you how to fix the latter, [Quinn Dunki] has made herself an absolutely deluxe screw shortening jig. And while that’s cool and all, the real value here is the journey; watching over [Quinn]’s shoulders while she’s in the machine shop is always illuminating.

First off, she starts with her old jig, which frankly makes us want one. It’s a short piece of aluminum angle stock with threaded holes in it. You thread the screw in as far as you want, and use the edge as a cutting guide. Very nice!

But aluminum threads wear out quickly so it works if you’re shortening dozens of screws, but gets wonky when you need to cut hundreds. The new jig is made out of steel, and has a slit that clamps the threads in place so she doesn’t have to hold the tiny screws with her other hand while sawing.

This video is, on the surface, about making an improved tool out of steel. But it’s the tips along the way that make it worth your watch. For instance “deburr early and often” is a recurring leitmotif here: it keeps the extra bits that form along any cut from messing up edge finding or vise registration. And yeah, she deburrs after every operation.

There are mistakes, and lessons learned along the way. We’re not going to spoil it all. But in the end, it’s a sweet tool that we’ve never seen before.

If you haven’t read [Quinn]’s series on machine tools that she wrote for us, it’s a treasure trove of machining wisdom.

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Valentine Heart

Valentine’s Day…Hacks?

How do you reconcile your love for hacking projects together with your love for that someone special? By making him or her a DIY masterpiece of blinking red LEDs, but in heart shape. Maybe with some custom animations, and in a nice frame with a capacitive touch sensor to turn it on or off.

Or at least, that’s what I did. The good news is that my girlfriend, now wife, understands that this sort of present comes from a place of love. And it probably didn’t hurt that I also picked up some flowers to frame it with, and cooked her favorite lunch later that afternoon.

But if I’m 100% frank with myself, I’d have to admit that this was about 50% “present” and 50% “project”. Of course it also helps that she gets me, and that she knows that I put a bunch of effort into making it look as good as it did, and maybe because of that she forgives the 50% project.

Valentine’s day projects are a high-wire balancing act. If any other project fails, you can just try again. But here, the deadline is firm. Cosmetics matter a lot more on Valentine’s day than the other 364 days of the year, too. And finally, you really have to know the gift-receiver, and be sure that you’re not falling deeper into the excuse-for-a-cool-project trap than I did. And don’t forget the flowers.

I pulled it off with this one, at least, but I do feel like it was close, even today. Have you ever made a Valentine’s hacking project? How’d it go?

(Note: Featured image isn’t my project: It’s a lot more colorful!)

Google FindMy Tools Run On An ESP32

As of about a day ago, Google’s reasonably new Find My network just got more useful. [Leon Böttger] released his re-implementation of the Android tracker network: GoogleFindMyTools. Most interestingly for us, there is example code to turn an ESP32 into a trackable object. Let the games begin!

Everything is in its first stages here, and not everything has been implemented yet, but you are able to query devices for their keys, and use this to decrypt their latest location beacons, which is the main use case.

The ESP32 code appears not to support MAC address randomization just yet, so it’s possibly more trackable than it should be, but if you’re just experimenting with the system, this shouldn’t be too much of a problem. The README also notes that you might need to re-register after three days of use. We haven’t gotten to play with it just yet. Have you?

If you’re worried about the privacy implications of yet another ubiquitous tracking system out there, you’re not alone. Indeed, [Leon] was one of the people working on the Air Guard project, which let iPhone users detect trackers of all sorts around them. Anyone know if there’s something like that for Android?

Thanks [Lars] for the hot tip!

 

Hearing What The Bats Hear

[Iftah] has been exploring the sounds beyond what we can hear, recording ultrasound and pitching it down. He made a short video on the practice, and it’s like a whole new world of sounds exists just outside of our hearing.

For instance, a dropped toothpick sounds like you’ve just dropped a piece of lumber, a broken lightbulb sounds like a shattered window, and a blackbird sounds like a blue whale. Besides simply sounding super, [Iftah] speculates that there’s some regularity here: that as you slow down the sound it sounds like it came from sources that are physically bigger. He follows this up in a second video, but if you just think about the basic physics, it makes sense.

If you’re interested in recording your own ultrasound, there are a bunch of options on the market. With modern audio processors running up to 192 kHz or even 384 kHz out of the box, all that’s missing is the high-frequency-capable microphone. Those aren’t unobtainable anymore either with many MEMS mics performing well above their rated frequency response specs. Recording ultrasound sounds like a fun and not-too-expensive project to us!

Of course, most of the ultrasound recording we’ve seen has been about the bats. Check out the Pipistrelle or this pair of DIY bat detectors for some good background. But after watching [Iftah]’s video, we’re no longer convinced that the cute little insectivores are the coolest thing going on in the ultrasound.

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Matthias Wandel Hates CNC Machines In Person

Prolific woodworking YouTuber [Matthias Wandel] makes some awesome mechanical contraptions, and isn’t afraid of computers, but has never been a fan of CNC machines in the woodshop. He’s never had one either, so until now he couldn’t really talk. But he had the parts on hand, so he built a wooden CNC router. It’s lovely.

The router itself is what 3D printer folks would call a bed-slinger, and it’s cobbled together out of scrap plywood. Some of the parts have extra holes drilled in them, but “measure once, drill twice” is our motto, so we’re not one to judge. He spends a lot of time making “crash pads” that keep the frame from destroying itself while he’s building it – once the CNC is actually controlling things with the limit switches, we presume they won’t be necessary, but their design is fun anyway.

If you’re at all interested in CNC machines, you should give this video a watch. Not because it’s done the “right” way, but because it’s a CNC that’s being built on a budget from first principles, by an experienced wood builder, and it’s illuminating to watch him go. And by the end of the video, he is making additional parts for the machine on the machine, with all the holes in the right places, so he’s already stepping in the right direction.

He doesn’t love digital design and fabrication yet, though. If you’re making one-offs, it probably isn’t worth the setup time to program the machine, especially if you have all of his jigs and machines at your disposal. Still, we kind of hope he’ll see the light.

Of course, this isn’t the first wooden CNC router we’ve seen around these parts, and it probably won’t be the last. If you want to go even more fundamental, [Homo Faciens]’s series of CNC machines is a lovely mashup of paperclips and potential. Or, if refinement is more your style, this benchtop machine is the bee’s knees.

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Software In Progress

Open source software can be fantastic. I run almost exclusively open software, and have for longer than I care to admit. And although I’m not a serious coder by an stretch, I fill out bug reports when I find them, and poke at edge cases to help the people who do the real work.

For 3D modeling, I’ve been bouncing back and forth between OpenSCAD and FreeCAD. OpenSCAD is basic, extensible, and extremely powerful in the way that a programming language is, and consequently it’s reliably bug-free. But it also isn’t exactly user friendly, unless you’re a user who likes to code, in which case it’s marvelous. FreeCAD is much more of a software tool than a programming language, and is a lot more ambitious than OpenSCAD. FreeCAD is also a program in a different stage of development, and given its very broad scope, it has got a lot of bugs.

I kept running into some really serious bugs in a particular function – thickness for what it’s worth – which is known to be glitchy in the FreeCAD community. Indeed, the last time I kicked the tires on thickness, it was almost entirely useless, and there’s been real progress in the past couple years. It works at least sometimes now, on super-simple geometries, and this promise lead me to find out where it still doesn’t work. So I went through the forums to see what I could do to help, and it struck me that some people, mostly those who come to FreeCAD from commercial programs that were essentially finished a decade ago, have different expectations about the state of the software than I do, and are a lot grumpier.

Open source software is working out its bugs in public. Most open source is software in development. It’s growing, and changing, and you can help it grow or just hang on for the ride. Some open-source userland projects are mature enough that they’re pretty much finished, but the vast majority of open-source projects are coding in public and software in progress.

It seems to me that people who expect software to be done already are frustrated by this, and that when we promote super-star open projects like Inkscape or Blender, which are essentially finished, we are doing a disservice to the vast majority of useful, but still in progress applications out there that can get the job done anyway, but might require some workarounds. It’s exactly these projects that need our help and our bug-hunting, but if you go into them with the “finished” mentality, you’re setting yourself up for frustration.

Time Vs Money, 3D Printer Style

A few months ago, Hackaday’s own Al Williams convinced me to buy a couple of untested, returned-to-manufacturer 3D printers. Or rather, he convinced me to buy one, and the incredible success of the first printer spurred me on to the second. TL;DR: Lightning didn’t strike twice, but I’d still rate it as worth my time. This probably isn’t a good choice for your first printer, but if you’ve done the regular maintenance on your first printer already, I’d recommend it for your second or twelfth.

As background, Al has been volunteering with local schools to teach a 3D printing summer class, and this means outfitting them with a 3DP lab on the dirt cheap. His secret is to buy last year’s model which has all of the features he needs – most importantly for the kids, automatic bed height probing – but to buy it from the scratch-and-dent shelf at Creality. Why? Because they are mid-grade printers, relatively new, but on deep discount.

How deep? I found an essentially endless supply of printers that retail for $300 on discount for $90 each. The catch? It might work, it might not. I bought my son one, because I thought that it would at least make a good project for us to work on together. Those plans were spoiled – it worked absolutely flawlessly from the moment we bolted it together, and he runs 24-hour jobs on the thing without fear. From the look of the build plate, it had been used exactly once and returned for whatever reason. Maybe the owner just didn’t want a 3D printer?

The siren song of straightforward success was too much for me to resist, and I picked another up to replace my aging A8 which was basically a kit for a 3D printer, and not a particularly good one at that, but could be made to work. My scratch-and-dent Creality came with a defective bed-touch sensor, which manifest itself as a random absolute refusal to print.

I took it apart, but the flaw is in the design of the V1 touch sensors – the solenoid requires more current to push down than the 3DP motherboard can reliably deliver. It works 100% of the time on my bench power supply, but in situ it fails about 30% of the time, even after hitting it with graphite and making sure everything is mechanically sound. Creality knows this and offers a free trade-in, just not for me. The new version of the Creality probe costs $50 new, but you can get cheap knock-off BL Touch models for $14. Guess what I did?

And guess what bit me? The cheapo touch probe descends a bit slower than the Creality version should, and the firmware is coded to time-out in an extra-short timeframe. Thankfully, Creality’s modifications to Marlin are all open source, and I managed to tweak and flash a new firmware that made it work 100% of the time, but this was at a cost of probably eight hours of bug-hunting, part-ordering, and firmware-compiling. That said, I got some nice extra features along the way, which is the advantage of a printer running open-source firmware.

So my $300 printer cost me $105, plus eight hours of labor. I only charge one coffee per hour for fun hardware debugging tasks, but you may have a different valuation. Taken together with my son’s printer, we have $600 worth of printer for under $200 plus labor, though, which starts to sound a little better.

Is gambling on an untested return 3D printer worth it? For us, I would say it was, and I’d do it again in a few years. For now, though, we’ve got three printers running and that’s all we need. Have you gone down this perilous path?