Ask HN: What rabbit hole(s) did you dive into recently?

When 3D printing became accesible I joined the subreddit for inspiration of what use I could put it to and the opposite happened. Everyone was making plastic toys and ironic reaches like an “egg holster”. Every so often someone would be able to fabricate a replacement part for something which I thought was the coolest. But beyond that. There wasn’t too much to be motivated by. I never got into it.

Here I wonder the same thing. Not that everything joyful must be productive. But if there was a way to apply this to something that was neat in the real world I think I’d be far more motivated to learn the skill. And enjoy it more.

I can empathize with your perspective. For everything genuinely useful thing like the Gridfinity storage ecosystem, there's a mountain of future landfill. There's only so many wifi router wall-mount brackets you need.

However, I am going to gently push back by pointing out that you're not connecting the dots between knowing how to use CAD to create solutions to problems, and having cheap 3D printers available that can make those solutions real.

In other words, your mistake might be looking externally for what you should be making. It's not so much a failure of imagination but not training your brain to make the possibility of creating objects one of the first steps on the path to problem solving. Perhaps a good analogy is how people go from asking GPT-4 things they've heard other people try to making asking GPT-4 about everything as normal as brushing your teeth.

So like, as much as it's awesome that I could realize I can print my own reels (for pick and place) from an STL off Thingiverse, my main use of my 3D printer at this point is to print off plastic prototypes of circuit boards and custom enclosures that I'm working on. Not only does this allow me to verify clearance (I actually saved myself five digits and months of pain recently by realizing that the 1/4" audio jacks would not allow my board to be inserted as designed) but it gives me something I can put in people's hands. I've found that, over many years, you can describe things to people and they will nod like they get it, and then when I put the real thing in their hands, they say something roughly like, "oh, this is what you meant". Which I used to find frustrating, and now I just accept it.

Right now, I'm working with the company in China that makes hard shell cases for basically every consumer product. They are sending me revisions of the insert that will hold everything safely. I print them off and then send photos and measurements back of how everything fits (or doesn't) which completely avoids the expensive and slow process of them making a mold, sending me a sample and me testing it. I've literally saved months and thousands doing this. It's awesome.

Similarly, you might have heard that injection molding is incredibly expensive to get started with and that there are fussy design rules you must follow. Well, engineers have recently clued in to the realization that we can essentially 3D print the molds, saving thousands and many lost weeks. Right now there's this crazy arbitrage where about 90% of product designers don't appear to realize that this is a thing, yet.

I could go on and on. The only takeaway is that as you normalize CAD and 3D printing as a go to tool the same way you probably think screwdrivers are pretty normal, you realize that you have more things you need a 3D printer for than things you need a screwdriver for. And that escalation can be really fast.

Addendum 1: Also, remember that it's not just 3D printing. Creating photo-realistic renders of something that doesn't exist yet can save the day. But there's also subtractive processes like CNC which is in some ways even more useful than additive processes like 3D printing. There's a Kickstarter right now for Carvera Air that a lot of folks should get in on.

Addendum 2: One of my very favourite theoretical use-cases for 3D printing is printing prosthetic limbs for animals. I say theoretical because I've never done it personally... but I intend to. I'm a total sucker for this concept and I want to have time to get involved someday. Lots of videos on YouTube, like https://www.youtube.com/watch?v=dP3Kizf-Zqg and https://www.youtube.com/watch?v=EynjYK45dyg and https://www.youtube.com/watch?v=sdFtMRko2GU

Leninism doesn't quite depart from Marxism really, Lenin expanded upon Marx's ideas and applied them to the evolving material conditions of Tsarist Russia. In a manner of speaking he departed with Marx in the way that Marx thought revolution would occur in developed industrialized nations like Germany and France and not rural agrarian societies like Tsarist Russia. Another thing to note is a lot of what Lenin wrote was scathing and sort of exaggerated polemics against others who he often worked alongside strategically, but argued with for the purpose of directing the course of action correctly. His ideas, the conditions and people he was responding to, evolved over time as well, so it's very important to understand those contexts going in, and this book does an excellent job of synthesizing and condensing some of that well: https://www.goodreads.com/book/show/26268757-revolution-mani...

I think this does a good job too: https://www.goodreads.com/en/book/show/50284837

I would also recommend The People's Forum / The Socialist Program's recent class on Lenin: https://m.soundcloud.com/thesocialistprogram/sets/lenin-and-...

interesting, why did you loose motivation?

I saw my grandparents go through 10 years of doing all the retirement things(beach, hobbies, social hour etc) to keep them more than busy. Then they kind of did it all and just started having social hour earlier and earlier every year into their 80s. Cocktail our started about 11:30 am in the end.

I'm starting my retirement and have so many interest/subjects I want to learn so feel like I can stay pretty entertained for more than 10 years but maybe not.

> Can you actually outperform the KEFs and Perlistens of the world? They seem to have so much engineering put into their designs I don't believe a hobbyist can realistically match them.

Absolutely. Don't forget, these guys are: a. Humans, and b. Operating for a company to make a profit. When you're DIYing you're (generally) not concerned about the latter part at all.

There's a few more reasons why DIY is so capable:

1. High quality drivers are available to purchase. There are companies like Tymphany/SB Acoustics etc that are OEM/ODM manufacturers selling to the big names. You can get the same/very similar models from parts express and other sites.

2. A lot of the engineering principles are well understood, public science. In fact many experts hang out on websites like DIYaudio.com. They're human. You can see their workings, opinions, doubts etc up close.

3. Some speakers like the Dutch&Dutch 8c's started their lives on forums like diyaudio. Which is to say, they went from DIY level to "well-reviewed" level in a manner that's quite clear/transparent to anyone familiar with the forum/DIY. No "hidden" black magic involved.

4. You have a lot of amazing designers on these forums putting their designs out for free. Jeff Bagby, Paul Carmody, Troels Gravesen, Perry Marshall etc. Check out Perry's comment on his speaker below. Btw, he's a professional designer having worked across a number of audio & car companies designing AV systems.

Now, if you want to design your own speakers and not use an existing model, yes you'll need to learn a lot. But it's very much doable. It may take time/money/effort, but beating a top of the line system for a fraction of the (material, not labour) cost is possible and has happened.

[0] - https://www.diyaudio.com/community/threads/ultimate-open-baf...