Fixturing and work holding can be huge problems for hackers. Let’s face it – that $5, alligator clip-festooned “Helping Hand” is good for only the smallest of workpieces, and the problem only gets worse as the size scales up. One can jury rig fixtures for things like microscopes and lights, but a systematic approach like this 3D-Printed work fixturing Erector Set really appeals to our need for organization.
As [Tinkers Projects] explains it, the genesis of this project came from a need to mount a microscope firmly over a PCB. Rather than build a one-off fixture, the idea of a complete system of clamps and connectors seemed to make more sense. Based on 10-mm aluminum rods and a bewildering number of 3D-printed pieces, the set has just about everything needed to fixture pretty much anything. There’s a vertical element that acts as the central support, connectors for putting another rod perpendicular to that, plus neat attachments like a three-fingered clamp for small cylindrical objects and a couple of blocks that act like a stick-vise for PCBs and similar workpieces. And yes, there’s even a fixture with alligator clips. The whole thing seems very well thought out and has a little mad scientist vibe to it, but while some fixtures look as if they came right from the chemistry lab, we’d be cautious about chemical compatibility and use near heat sources.
[Elliot Williams] did a rundown of what people are using for helping hands a couple of years ago which made us covet articulating dial indicator arms for our bench. Still, [Tinkers Projects]’ approach has a lot of appeal and is probably cheaper and more versatile to boot.
Have you ever wondered how switchable magnets work? Not electromagnets, but those permanent magnet fixtures like the ones that hold dial indicators to machine tools, or the big, powerful chucks for surface grinders that can be mysteriously demagnetized at the flick of a lever. It seems like magic.
Thanks to [Andrew Klein] and this video on shop-built magnetic switches, the magic is gone. As it turns out, the ability to nullify the powerful magnetic field from a bunch of rare earth permanent magnets is as simple as bringing in another set of magnets to cancel out the magnetic fields of the first set.
[Andrew]’s magnetic pucks are formed from two thick plywood discs with magnets set into the edges. These magnets alternate in polarity around the discs, and they match up with mild steel pole pieces set into the face of the discs. The two discs swivel on a common axis; when the top disc is swiveled so that the polarity of the top and bottom magnets align, the magnet is switched on. Swiveling the top 60° puts the opposing fields in line with each other, canceling out the powerful combined pull of all the magnets and releasing the fixture.
[Andrew] sells a set of plans for the magswitches, which he built using standard woodshop tools. We think the design is perfect for a CNC router, though, where the fussy boring and counterboring operations might be a little easier. Perhaps even a 3D-printed version would be possible. This isn’t the first switchable magnet we’ve seen, of course, but we like this one because it’s all mechanical.
Continue reading “Shop-Built Fixtures Reveal The Magic Of Switchable Permanent Magnets”
When we see a new build by [Gord] from Gord’s Garage, we never know what to expect. He seems to be pretty skilled at whatever he puts his hand to, with a great design sense and impeccable craftsmanship. You might expect him to tone it down a little for a STEM-outreach wind turbine project then, but when you get a chance to impress 28 fifth and sixth graders, you might as well go for it.
Starting with an idea from his daughter’s teacher for wind turbines each kid could make, [Gord] applied a little lean methodology so the kids would be able to complete the build in the allotted time. The design is simple – a couple of old CDs holding vertical sections of PVC tubing to catch the breeze and spin neodymium magnets over four flat coils of magnet wire. It’s enough to light a single LED and perhaps a kid’s imagination.
As simple as the turbine is, the process of building it needed to be stripped of as much unnecessary work as possible, and [Gord] really shines here. He built jigs and fixtures galore, pre-built some assemblies, and set up well-organized workstations for each step of the build. Everything was clearly labeled, adult volunteers were trained using the video after the break, and a good time was had by all.
Sometimes the hack isn’t in the product but in the process, and [Gord] managed to hack a success out a potential disaster of disappointed kids. If getting a taste of [Gord]’s style makes you want to see more, check out his guitar fretting jig or his brake rotor mancave clock.
Continue reading “Lean Thinking Helps STEM Kids Build A Tiny Windfarm”