Aren’t ball races and marble runs fun? Wouldn’t they be so much more enjoyable if you didn’t have to climb back up the ladder each time, as it were, and reset the thing? [Johannes] wrote in to tell us about a wee robot with the Sisyphean task of setting a ball bearing on a simple but fun course, collecting it from the end, and airlifting it back to the start of the track.
[Johannes] built this ‘bot to test small-scale resin printing strength as well as the longevity of some tiny linear actuators from Ali that may or may not be available at a moment’s notice. The point was to see how these little guys fared when connected directly to an Arduino or other microcontroller, rather than going the safer route with a motor driver of some kind.
Some things worked well, like the c-clips that keep the axles together, and using quick pulses to release the magnetically-linked ball from the gripper. Other aspects didn’t work out so well. Tiny resin parts do not respond well to force, for starters. And then there’s the actuators themselves. The connections are fragile and the motors are weak, but they vary wildly in quality from piece to piece, so YMMV. Some lose steps, and others occasionally seize. But you wouldn’t know any of that from the graceful movement capture in the video below. Although it appears to be automated, the bot is under remote control because of the motor issues.
Not into ball runs? There are other Sisyphean tasks available, such as moving sand around in the name of meditation.
Continue reading “Sisyphean Ball Race Robot Toils Gracefully, Magnetically” →
Ball and socket joints are useful, but making a part slide over the surface of a sphere, held by magnets, requires a lot of fiddling to get right. We admire persistence and nailing all the details. [Matthew Finlay] has been doing just that with his ball and socket robot. He’s on version six, a testament to his desire to do the idea justice. Luckily for us, he’s documented each version as he went.
Version one, made from a DIY Christmas ornament ball, had no stability around the radial axis, and oscillated badly. Version two demonstrated the problem of centering the mechanism in the ball. Version 3 fixed this problem (it’s covered in the same video). Then version four fixed many of the assembly issues and replaced the servo controllers with an Arduino, but the ‘arm’ piece was too small and mechanically iffy.
Version five used a fabricated bearing. Matthew used airsoft rounds as the balls. Not a good idea. And assembly was a nightmare. So all this progress up to version six shows his improving technique. Artists say ‘work on your process, not on your pieces’. He’s become much more analytic about what’s needed. He’s started measuring the strength of the robot, and handled issues like adding limit switches so it doesn’t crash at the limits of travel.
Fun build, reminds us of [Stephen Dufresne]’s BB-8.
Continue reading “Practice Makes Perfect For This Ball And Socket Robot” →
[Mcjack123] has been getting into chiptunes lately and realized that his original interest started in 2018 when he used an Arduino to turn a TI-84 calculator into a sound machine. His latest iteration is a custom-designed soundboard and he takes us through the design and construction of it in a recent post.
The work models classic sound generators like the 2A03 or the Commodore 64 SID. You have a bunch of simple waveform generators along with filters and modulators to make various effects. These boards eventually gave way to FM synthesis devices like the Yamaha OPL2 and OPL3 chips. All of these cards accepted commands and generated audio on their own. More modern boards are more likely to simply convert digital data from the computer into audio.
Continue reading “Sound Generation Board Makes The Tunes” →
Calling all hams! Hamvention 2022 is underway and runs through the weekend at the Greene County Fair and Expo Center in Xenia, Ohio. It’s been three long years since Hamvention took place in person, and this year marks the 70th reunion of what has got to be the largest hamfest in the Midwest. If you’re in the area, you don’t want to miss it. You will need a ticket, though, and here are a few places you pick one up.
Indoors, you’ll find six buildings full of commercial vendors. But outside is where the real fun takes place — the flea market. What treasures will you uncover? There’s only one way to find out.
If you want to get into ham radio, there’s no place like a ham fest to kick off your journey. And if you’ve been poring over the ARRL handbook, you’re in luck, because they’re proctoring ham exams for free at the church across the street on Friday and Saturday.
Can’t make it out for whatever reason, but live close to the fairgrounds? Want to get in the mood on your way there? Tune to 1620AM within a five-ish mile radius to hear weather, traffic, and parking info, plus interviews and other assorted radio fun. If you live nowhere near Ohio, don’t despair — they are livestreaming it on YouTube.
[Note: the Hara Arena, pictured in our awesome Joe Kim artwork, is the old home of Hamvention, and was demolished in 2016. Better head off to the Greene County Fairgrounds instead.]
If you’re looking for the perfect excuse to buy that big, beautiful Bridgeport mill, we’ve got some bad news: it’s not going to be making perfectly square end cuts on aluminum extrusion. Sadly, it’s much more cost-effective to build this DIY squaring jig, and search for your tool justification elsewhere.
There’s no doubting the utility of aluminum extrusion in both prototyping and production builds, nor that the versatile structural members often add a bit of class to projects. But without square cuts, any frames built from them can be seriously out of whack, leading to misery and frustration down the road. [Midwest Cyberpunk]’s mill-less solution uses a cheap Harbor Freight router as a spindle for a carbide endmill, riding on a laser-cut acrylic baseplate fitted with wheels that ride in the V-groove of — you guessed it — aluminum extrusions. A fence and clamping system holds the extrusion firmly, and once trammed in, the jig quickly and easily squares extrusions that have been rough cut with a miter saw, angle grinder, or even a hacksaw. Check out the video below for a peek at the build details.
We love the simplicity and utility of this jig, but can see a couple of areas for improvement. Adding some quick-throw toggle clamps would be a nice touch, as would extending the MDF bed and fence a bit for longer cuts. But even as it is, this tool gets the job done, and doesn’t break the bank like a mill purchase might. Still, if your heart is set on a mill, who are we to stand in the way?
Continue reading “Square Cuts On Aluminum Extrusion, No Mill Required” →
Join Hackaday Editor-in-Chief Elliot Williams and Assignments Editor Kristina Panos as we take a tour of our top hacks from the past week. Elliot brought some fairly nerdy fare to the table this time, and Kristina pines for physical media as we discuss the demise of the iPod Touch, the last fruit-flavored mp3-playing soldier to fall.
But first, we talk about a why-didn’t-I-think-of-that 3D printing hack that leverages vase mode into something structural. We’ll take a look inside a see-through cyberdeck made from laptop parts, marvel over the minuscule voltages that can be picked up with a bit of meticulous meter design, and chew the fat about old rotary phones.
We also put in some overtime discussing a cheap fix for an expensive time card clock part, and rock out to a guitar that can use various things for its resonant cavity. Finally, Elliot questions the difference between software and firmware when it comes to hiding your dirty secrets, and Kristina bloviates about see-through electronics and music appreciation using whatever format you can afford.
Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments below!
Direct Download link
Continue reading “Hackaday Podcast 169: 3D Printing In Vase Mode, Measuring Nanovolts Through Mega DIY, And The Softest Pants Are Software Pants” →
Pinewood derby racing is a popular pastime for scouting groups and many others besides. [Mr Coster] whipped up his own track with the assistance of some 3D printed parts, and used it to run a competition with a fun twist on the usual theme.
The track starts with a pair of MDF panels, on to which some strips are placed to act as guides for the racers. There’s also a release mechanism built with hinges and a pair of dowels that ensures both racers start the competition at exactly the same time. To give the track a nice transition from the downward slope to the horizontal, a series of curved transition pieces were designed in Fusion 360, 3D printed, and added to the course.
As for the competition, [Mr Coster] decided to eschew the usual focus on outright speed. Instead, students were charged with building the slowest possible car that could still complete the course. Just for the fun of it, though, the kids were then given one day to modify their slowest cars to compete in a more typical fastest-wins event. It gives the students a great lesson in optimizing for different performance parameters.
You might be old-school, though, and want to ruin the fun by taking it all way too seriously. Those competitors may wish to consider some of the advanced equipment we’ve featured before. Alternatively, you could run a no-holds-barred cheater’s version of the contest. Video after the break.
Continue reading “Slow Races On A Pinewood Derby Track Built From Scratch” →