Old Christmas Tree Gets A New Spin

A couple of Christmases ago, [Nick] got tired of trying to evenly decorate his giant fake tree and built an MDF lazy Susan to make it easy as eggnog. But what’s the point of balanced decorations if one side of the tree will always face the wall? This year, [Nick] is giving himself the gift of a new project and motorizing the lazy Susan so the tree slowly rotates.

The saintly [Nick] decided to do this completely out of the junk box, except for all the WS2811 RGB LEDs on order that he hopes to synchronize with the tree’s movement. He started by designing a gear in OpenSCAD to fit the OD of the bearing, a task made much simpler thanks to the open-source gear libraries spinning around out there.

It was hard to get slow, smooth movement from the NEMA-23 he had on hand, but instead of giving up and buying a different motor, he designed a gear system to make it work. Our favorite part has to be the DIY slip ring [Nick] made from a phono connector to get around the problem of powering a rotating thing. This is a work in progress, so there are no videos just yet. You can watch [Nick]’s Twitter for updates.

[Nick] didn’t specify why he chose to use WS2811s, but they have gotten pretty cheap. Did you know you can drive them with VGA?

Via Adafruit’s CircuitPython newsletter

A Modern Take On A Piece Of Old Test Equipment

The HP 11947A is something of a footnote in the back catalogue of Hewlett Packard test equipment. An attenuator and limiter with a bandwidth in the megahertz rather than the gigahertz. It’s possible that few laboratories have much use for one in 2019, but it does have one useful property: a full set of schematics and technical documentation. [James Wilson] chose the device as the subject of a clone using surface mount devices.

The result is very satisfyingly within spec, and he’s run a battery of tests to prove it. As he says, the HP design is a good one to start with.   As a device containing only passive components and with a maximum frequency in the VHF range this is a project that makes a very good design exercise for anyone interested in RF work or even who wishes to learn a bit of RF layout. At these frequencies there are still a significant number of layout factors that can affect performance, but the effect of conductor length and  stray capacitance is less than the much higher frequencies typically used by wireless-enabled microcontrollers.

Hackaday Links: December 15, 2019

When you’re right, you’re right. Back in January, we predicted that exoskeletons were about to break out as a mainstream product, and gave several examples of prototypes poised to become products. So it was with interest that we read about Sarcos Robotics and their new Guardian XO, a cyber suit aimed at those doing heavy lifting tasks. The wearable, full-body exoskeleton is supposed to amplify the wearer’s effort 20-fold, making a 200-pound load feel like lifting 10 pounds. It runs untethered for two hours on hot-swappable battery packs, and will be offered for lease to civilian heavy industries and the military for $100,000 a year. Honestly, it seems like you could hire a fair number of meat-robots for that sum, but still, it’s an interesting technology and a promising development.

Aficionados of 3D printing know all too well the limitations of the technology. While we’ve come a long way with things like a print in place, multiple materials, embedded electronics, and even direct 3D printing of complex mechanisms like electric motors, there’s been a long-standing obstacle to turning the 3D printer into the replicators of the Star Trek universe: batteries. But even that barrier is falling, and a new paper shows just how far we’ve come to printing batteries right into our designs. Using an off-the-shelf Prusa Mk 3 and specially formulated lithium iron phosphate/PLA and silicon dioxide/PLA filaments, the group was able to print working batteries in one shot. It’s exciting news because previous 3D-printed batteries required special printers or laborious post-processing steps. We’ll be watching for developments here.

Speaking of laboratory work, anyone who has been around labs is probably familiar with LabVIEW, the de facto standard for programming data capture and automation applications in the laboratory setting. The graphical programming language makes it easy to throw together a quick interface, and many lab-rats regret not having the expensive, proprietary environment available for their after-hours hacking. That might no longer be true, though, with special LabVIEW licensing for non-commercial users. It looks like there are two levels: LabVIEW Home Edition and a Community Edition of LabVIEW, which is currently in Beta. Either way, it’s good news for LabVIEW fans.

Friend of Hackaday Eric Strebel released a video the other day that we just had to comment on. It has nothing to do with electronics – unless you’re into circuit sculpture, that is. In the first of a two-part series, Eric covers the basics of modeling with brass and copper, using both wire and tubing. He has some great tips, like work-hardening and straightening copper wire by stretching it, and the miniature roll bender seen at 7:40 looks like something that could easily be 3D-printed. We recently did a Hack Chat on circuit sculpture with Mohit Bhoite, and saw his Supercon talk on the subject, so this video really got the creative juices flowing.

If you’re local to the Elkhorn, Wisconsin area, consider stopping by the Elkhorn Mini Maker Faire on February 15 and 16. Elkhorn looks like it has a nice central location between Milwaukee and Madison, and doesn’t appear too far from Chicago either, which is probably why they drew 1,200 people to the inaugural Faire last year. They’re looking to get that up to 2,000 people this year and over 150 booths, so if you’ve got something hackish to show off, check it out. The organizers have even set up a Hackaday.io event page to coordinate with the Hackaday community, so drop them a line and see what you can do to pitch in.

And finally, this one has us scratching our head. Activist group Extinction Rebellion (XR) has claimed they’ve “decommissioned” thousands of electric scooters in French cities. Why they’ve done this is the puzzler; they claim that the scooters-for-hire are an “ecological disaster” due to the resources needed to produce them compared to their short lifespan. We haven’t done the math. What is interesting, though, is the mode of decommissioning: XR operatives simply defaced the QR code on the scooters, rendering them un-rentable with the vendor’s smartphone app. Scooter companies might want to look into alternative rental methods if this keeps up.

A LED Cube Designed For Easy Assembly

LED cubes are mesmerizing and fun, but they’re usually a pain to build. Not so with [burkethos]’s cleanly designed cube. 

Many cubes are put together in an elaborate sculptural style. Traditionally the leads of the LEDs are artistically bent and then hours are spent laboring over the future rainbow Borg cube. This build is more reminiscent of a motherboard or back plane design. The LEDs are surface mount units re-flowed onto a rake shaped PCB. At the base of each “rake” there’s a right angle male header. This is then soldered to base board which creates a reliable mechanical bond.

There are some downsides to this approach. For example, the PCBs occlude the LEDs at some viewing angles. However, this can be mitigated with careful placement in the room, or in one variation, mounting the cube at a different orientation so the rakes are horizontal rather than vertical.

Regardless, we appreciate this new take on an old project and can definitely see it having a more universal appeal than the kits that require a couple weeks of afternoons to finish.

The Boxy All-In-One Nintendo 64 Your 1990s Self Always Wanted

In 1997, chances are that if you didn’t have a Nintendo 64 already, you wanted one. (Never mind that the games cost the GDP of a small country.) It gave you both the supreme game designing talent of Shigeru Miyamoto and graphics that left the Sony behind. The trouble, though, was that like all consoles, the N64 required a large TV set and a load of wires. There was never a compact all-in-one version that integrated console, display, and speakers in the same package, and that was something [Mason Stooksbury] evidently considered to be a shame. A couple of decades late, he’s created the all-in-one Nintendo 64 appliance that the games giant never made in the ’90s, and we’re lucky enough to be able to take a look at it.

The starting point for the build is entirely in-period, the shell of a late-1990s Compaq CRT monitor. In the front goes a laptop display panel with a monitor conversion board, leaving plenty of space behind for a pair of full-size speakers. On top of the speakers sits a bare N64, with the controller ports brought out to the front panel below the screen. It’s not all retro though, there is also an HDMI converter and an HDMI output to drive a modern TV if desired. The N64 itself has an interesting backstory, it was his original console from back in the day that died following a lightning strike, and he brought it back to life decades later after some research revealed that the N64 PSU has a fuse.

Would an all in one ’64 have sold like hot cakes in ’97? Probably, and we’d be featuring all sorts of hacks on them today. As it is, portable N64s seem to feature most often here.

See How Wildly Different Air Conditioners Can Be (On The Inside)

Air conditioners are easy to take for granted. From refrigerators to climate control, most of us would miss them dearly if they disappeared. That’s part of what draws [Josh Levine]’s interest in air conditioners, and he has provided an interesting tour of several different units and how different they can be, despite all working in basically the same way.

That white PCB is crucial (for running the bluetooth speaker and LED flashlight, that is.)

One way that air conditioners try to stand out is by being quiet, and the bulk of noise comes from the fans and the compressor. One unit (the Haier Serenity) aimed to be the quietest unit possible, but while this effort had mixed results at best it is still interesting to see [Josh] give a tour of the different ways they tried to reduce noise (YouTube, embedded below). Noise-limiting elements include the unusual step of using separate motors for the indoor and outdoor fans, and even little counterweights to ensure they are perfectly balanced, just like wheel weights on automobile tires.

Another notable air conditioner is the Zero Breeze, a portable unit that was the product of a Kickstarter campaign. Features included (either bizarrely or predictably, you be the judge) a bluetooth speaker and an LED flashlight. [Josh] more than half suspected the product would never actually ship, but was pleasantly surprised. Not only did it deliver, it turned out to be a pretty nice design with only a couple of mildly head scratching moments (YouTube, also embedded below).

There are a few more to check out in the roundup on [Josh]’s web site, which he also compares and contrasts with his own DIY unit which we featured in the past.

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The Home-Made Drill Press Of Your Dreams

We are lucky to live in an age when tools have almost never been so affordable, when if we’d like a drill press on our benches we can pick one up for not a lot from our nearest discount store. If the cheapest tools aren’t very good quality then even the better ones aren’t that much more expensive. It’s evident that [Workshop DIY] has the resources to buy a decent drill press if he wanted one, but we’re fortunate that instead he’s taken the time to build one of his own from scratch (Russian language audio, Anglophones will have to enable YouTube subtitle translation).

The press itself is made entirely from box section steel tube, with what looks like 25mm square used for the base and 50mm for the vertical shaft. Instead of a rack and pinion to raise and lower the tool it has a slider that runs on a set of bearings and is lifted with a bicycle chain. The chuck itself is mounted to a shaft that runs through another set of bearings to the large pulley and motor from a washing machine. The result is a beautifully made drill press that seems to work very effectively. It may lack an adjustable table or selectable speeds, but we certainly couldn’t build it better than he has. Take a look, the video is below the break.

It shouldn’t be surprising what can be made in a well-appointed metalworking shop, perhaps we have been blinded by the convenience of readily available tools. If you’d like to see more, take a look at this DIY engine crane.

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