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Ask HN: What's the coolest physical thing you've made?

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Re: Ask HN: What's the coolest physical thing you've made?

#411

Post by tinco »

avar wrote: post #370
tinco wrote: post #191

Earlier quoted context omitted.

I had the gas heater checked by a professional who agreed to do the yearly maintenance. The electrical wiring you shouldn't do if you're not serious about electrical safety, and not reverent to the industry standards. I read the Dutch standards for electrical wiring, but it's actually hard to do it wrong if you have a small house and no complications like solar panels because building stores don't even sell wrong mat…

> I read the Dutch standards for electrical wiring Aside: Do you have a handy link to those standards? > it's actually hard to do it wrong [...] building stores don't even sell wrong materials. It's quite easy to get it wrong, e.g. buy stranded instead of solid wire, then plug it into a wago connector.

So the core standard is called NEN1010 and it costs money to get it. The way I got it is they had just built an app for reading the standards and they were offering a trial of the app. So I got the trial, dumped the entire NEN1010 and some accompanying docs and read them at my leisure.

I don't think I've seen stranded wire at the Hornbach. Of course you could do it wrong if you buy your wire in entirely the wrong section, and don't even bother to read the instructions of the wago connectors. I meant it's hard to do it wrong if you're trying to do it right. Hopefully that makes sense :p

Re: Ask HN: What's the coolest physical thing you've made?

#412

Post by nkg »

ryandrake wrote: post #167

Built a two-seat, single engine airplane. Took 6.5 years to build and I've been flying it for close to a year now. The U.S. and several other countries have fairly liberal rules allowing for home-built aircraft, so there are actually tens of thousands of home-built planes flying around today. Yes, it's built from a kit (mostly sheet aluminum and rivets, some fiberglass) but I'm OK with calling it cool.

That is cool.

Re: Ask HN: What's the coolest physical thing you've made?

#413

Post by joshfee »

I made a spinning LED sphere that has 72 addressable RGB LEDs on a 3-spoke "propeller" that spins on 2 axes. This is still a work in progress, as I need to design the final control board PCB so that it's not a bunch of breadboard wires, but the main physical assembly is complete.

* Got and learned how to use a 3D printer

* Learned parametric CAD in Fusion 360 to design the main assemblies that the motors, slip rings, and propeller attaches to.

* Learned how to design PCBs and had them made

* Re-learned soldering and did SMD soldering for the first time

* Learned some ESP32 programming to control it with bluetooth (I have plans to have a robust live-editor so you can control the light patterns from a tablet - currently on pause)

Video: https://photos.app.goo.gl/xYPSHeebGzZP7Mw47

Re: Ask HN: What's the coolest physical thing you've made?

#414

Post by bityard »

CoastalCoder wrote: post #78
egberts1 wrote: post #47

All before 1982: a belt-driven windmill to an auto alternator, complete with a household DC circuit providing switchable lights. (thanks Popular Mechanic magazine!) a 6' multi-stage magnetic-driven projectile launcher complete with a horkage of old TV capacitors. An amplified passive Ultrasonic sniffer with earphone. An alarm trip sensor comprised of mirrored lightbeams. And created/deployed "THE" original credit car…

How did you make a reader like that back then? I'm assuming that these days, and such device would use a generic microcontroller, with most of the interesting logic in the software. (Insert snarky joke about it also requiring Electron and 16GB of RAM.)

IIRC, a credit card magstripe can be read with a regular cassette tape head. Which were, if not quite ubiquitous yet, common enough in the late 80's/early 90's. Converting the analog pulses to the card's 16-digit (or whatever) number was almost certainly done with discrete logic at first.

I'm not sure what OP means about creating the "original" credit card reader, unless he was working for one the credit card companies rolling out the technology. (Doesn't make any sense to me that they would put magstripes on their cards without selling the readers to merchants too.)

Re: Ask HN: What's the coolest physical thing you've made?

#416

Post by 0xbs0d »

Back in the days of the Amiga, me and a friend were in high school and we were obsessed with Formula 1GP from Microprose so we took a couple of joysticks apart and we built ourselves the pedals and a wheel with gear shifts. It was pretty trashy looking but worked remarkably well.

Re: Ask HN: What's the coolest physical thing you've made?

#417

Post by leoqa »

tracker1 wrote: post #401
mattbrewsbytes wrote: post #211

Earlier quoted context omitted.

Similarly, I have felt huge satisfaction with DIY repairs. Re-plumbing a couple sinks and replacing a garbage disposal and/or adding a dishwasher is not hard to do, the building codes aren't terribly overbearing and its like Lego connecting things together with immediate feedback loop when testing for leaks (modern PVC plumbing, not older copper/metal). When you own a home and have the time, there are some tasks that…

Yeah, that's the spot I'm in right now... contract rates where I live went through the roof over the pandemic and never came back down. Aside: I wish I could smack whoever did the wiring in my home. They saved a few dollars on a breaker, but if I run my AVR/TV + Microwave (in adjacent kitchen) and the lights are on in the summer, it blows the breaker. And there's a dozen spaces on the box still available even.

Can you just swap to a bigger breaker if the cable is sized properly?

Re: Ask HN: What's the coolest physical thing you've made?

#418

Post by cossatot »

ratrocket wrote: post #94
cossatot wrote: post #80

You guessed it, boats. I have built a stitch and glue (plywood) sea kayak[0], an Aleutian-style skin-on-frame sea kayak[1], and a skin-on-frame canoe[2]. All were fairly approachable and straightforward projects (I built the first two with basically some hand tools, a drill and a jig saw, on my deck, but a table saw is highly recommended for skin on frame). Tons of fun and the feeling of being a couple miles offshore…

Very cool! I've been wanting to build either a Cape Falcon canoe or F1 kayak for a few years (and might get the chance -- read, "have the space to" -- soon). If you see this & can elaborate, how did the Cape Falcon build process compare to the stitch and glue CLC and to the non-Cape Falcon skin-on-frame? Also, do you find yourself using one or the other of the boats more or less? Either way/no matter what, fun to see…

The Cape Falcon plans are far more detailed so there is a lot less figuring out stuff by yourself, relative to getting written plans. It's definitely a much more efficient process and there is probably a lot less variance in the result. I winged it on my Aleutian kayak a lot with mixed results (I gave it a lot of rocker and some other whitewater-inspired geometry). Of the kayaks, I prefer the Aleutian skin on frame although it was quite painful before I got the seat dialed in, and sometimes I can't roll it very well (I'm an expert whitewater boater and have a very solid roll), and its top speed is low. But it is very light, maneuverable, quiet (waves hitting it don't make much sound) and the peaked deck sheds water so it doesn't spray your face when you are punching through waves in the surf. The F1 is probably best of both worlds.

The Cape Falcon canoe that I built deviates a bit from the design pattern because I wanted a wide and flat bottom with harder edges, similar to a lot of modern Royalex tandem canoes. It's a 16' tandem I think, and even though it is pretty wide, it is still less stable than most canoes. However it is fast and extremely maneuverable in Class III.

Skin on frame is also awesome because when you are loading or unloading a 17' boat in a crowded beach parking lot and smack the bow into the car next to yours, it doesn't do any damage to either car or boat, or so I hear.

Stitch and glue is straightforward but the woodworking part goes fast and then it's just a ton of fiberglass work, i.e. cycles of epoxy and sanding, which is not that enjoyable for its own sake. On the other hand, one of the great parts of skin on frame construction is that other than a short amount of time ripping the ribs on a table saw, the rest is basically quiet and without harsh chemicals, so you don't need earmuffs or a respirator and can listen to music and have a snack/drink.

Stitch and glue will last forever if you protect it from UV, however skin on frame will most likely need to be reskinned in 5-10 years or so.

Re: Ask HN: What's the coolest physical thing you've made?

#419

Post by dekhn »

I've built a few cool things over the years. For a while I was on the Making and Science team at Google and it was my job. I helped contribute to the "physical google doodle" (where all the letters had interactive exhibits that kids could play with) and turned a shapeoko into a microscope. We used it to watch daphnia- at some point the daphnia "gave birth" and a mom who was watching said "we just saw the miracle of life!"

I built a Galton Board to demonstrate the Central Limit Theorem, I want to re-do it in all-acrylic and aluminum at some point and add an automated mechanism.

These days I build small motorized microscopes and use them to track tardigrades using an object detector. When the tardigrade moves, the detector detects the center of the tardigrade and moves it to the center of the image. This tracks tardigrades for hours at a time!

Ultimately, I'd like to make interesting nanoscale systems but the scope is as far as I've got.

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