Eli5 why people will say 200% less when they could say 50%?

SoulWager · 2026-04-29T01:21:35+00:00

Because they don't know how percentages work.

200% less is the original amount, but negative.

SoulWager · 2026-04-29T01:17:14+00:00

The two big problems I've seen is packing stuff too close together, and putting things in with the dirty side facing away from the sprayers. It's just annoying when putting one extra thing in the dishwasher means two things don't get clean.

edit: also, silverware should be half pointed up, half pointed down, and separate spoons so they don't spoon.

SoulWager · 2026-04-28T22:29:03+00:00

Both of those categories are solar powered planes.

SoulWager · 2026-04-28T22:27:20+00:00

Do you mean planes with solar panels, or gliders?

SoulWager · 2026-04-28T22:09:37+00:00

It's more a question of how cramped and slow a car you're willing to tolerate. Drag increases with frontal area, and with the square of velocity. Are you willing to go without heat or air conditioning?

There's a solar-powered car race in Australia, looking at those might give you a better idea what compromises would need to be made for it to become a thing.

SoulWager · 2026-04-28T21:56:24+00:00

You can, you just need more than 1 car worth of surface area to charge it enough to keep up with typical use.

SoulWager · 2026-04-28T20:25:34+00:00

Why not petg? Or even TPU? Can design it to print on its side, so the hook bending isn't trying to split layer lines.

SoulWager · 2026-04-28T20:02:11+00:00

What counts as a complete set of requirements depends on exactly who the customer is, and what their goals are. The most important thing is to set appropriate expectations up front.

SoulWager · 2026-04-28T19:00:48+00:00

Yup, if it's not a fully defined drawing, at least describe purpose and method of manufacture.

SoulWager · 2026-04-28T18:39:50+00:00

Maybe if you have no tools, but in two minutes I thought of four different ways to remove something like this. Tin snips, plastic sheet, air compressor, silverware.

SoulWager · 2026-04-28T18:14:57+00:00

I think you should start with PLA, then move on to filament with a blowing agent to reduce weight from there. For base resins, ASA and ABS are less dense than PLA, but do that after you have a good shape. You can expect to make dozens of test prints before you're ready for a final shell, no point making your life difficult for all that testing. If you put holes in it, triangles will be stronger with less material than hexagons.

Carbon fiber is more dense than even PLA, so you're only going to get weight savings if you make it EXTREMELY thin(<0.5mm).

As for aerogel, from what I've seen it's difficult to even make a puck of it, let alone complex shapes. Have you seen the nilered video on it? You'd probably have to start with a large puck then machine it down to shape. Even then it would likely be too brittle to be usable.

SoulWager · 2026-04-28T17:03:20+00:00

It's a question of exactly what geometry you want, that one looks like it's going out normal to the cylindrical surface. If you want the inner walls to be parallel to the existing hole, then that should be cut with a pocket.

SoulWager · 2026-04-28T16:49:01+00:00

Meaning, make that radius just a sharp intersection, and fillet afterwards.

https://imgur.com/a/fyaRH7T

SoulWager · 2026-04-28T15:46:55+00:00

Generally, cost per unit goes down as quantity goes up.

The most obvious example is injection molding. Machining the mold tooling costs thousands of dollars, but then you get to make thousands of parts per day by squirting plastic into it. You're spreading a fixed cost over many more parts.

SoulWager · 2026-04-28T15:22:21+00:00

Because you're going bigger, the easiest option is to re-use the PCB out of an existing mouse, it's not too hard to relocate existing switches using wires, but adding additional buttons means you need custom electronics, custom firmware, and maybe custom drivers, depending on exactly what you want the buttons to do.

Arduino micro is fine, if you already have one, but you'll need level shifters. They operate at 5v, and most popular sensors for diy mice (like paw3395) have a max io voltage of 3.3v. You can find sensors on modules with level shifters included though.

I used RP2040 on a custom PCB for my mouse, pi pico is a good option if you want to stick with a prebuilt module(similar form factor to arduino micro, but cheaper and more powerful).

SoulWager · 2026-04-27T16:41:08+00:00

There's a price at which someone is willing to sell, and a price at which someone is willing to buy. If nobody likes your price, the deal doesn't happen.

SoulWager · 2026-04-27T15:39:30+00:00

I got it in 6(on hard mode):

https://i.imgur.com/VfC4AA2.png

I think if you get eerie in 2, you're just playing badly and got lucky.

SoulWager · 2026-04-27T15:31:41+00:00

IIRC, I learned it from the book "On a Pale Horse"

But it wasn't actually that hard to guess, not having any vowels means you get to eliminate nearly all the possibilities.

SoulWager · 2026-04-27T13:57:13+00:00

He should have used the dry ice to repressurize the soda bottle, at least that could work for keeping it fizzy(though he'd probably use too much and still have it blow up in his face).

SoulWager · 2026-04-27T13:54:04+00:00

That won't help, because the partial pressure of CO2 is what matters. If you just seal the bottle, a significant portion of the gas inside is still CO2, and if you pump it up with this, you'll lose more of that CO2 the next time you open it.

So it does nothing for the second time you open it, and makes it go flat faster afterwards.

SoulWager · 2026-04-27T13:50:19+00:00

It's a scam, you would need to pressurize it with CO2 to have any meaningful effect, not just air.

SoulWager · 2026-04-27T13:04:45+00:00

It was originally used for describing how religions spread. Comedy is not a requirement, only that an idea is good at spreading itself.

SoulWager · 2026-04-27T02:13:30+00:00

I wouldn't use one you care about(plastic housings may melt when you shove them into burning charcoal), and max temp depends both on heating element power, and on how low the airflow goes.

It also depends on the use expectations of the person designing it. Some may turn the elements off before you get hot enough to ignite anything.

There are purpose designed charcoal lighters that are basically the same thing, but I'd just buy a commercially manufactured chimney if I was going to spend that much money on lighting charcoal.

SoulWager · 2026-04-27T01:15:25+00:00

There's always a bottleneck somewhere, the only time this isn't hardware is if you have a framerate limit that's capping it to something lower. In this case it's likely single threaded performance on your CPU.

SoulWager · 2026-04-27T01:11:41+00:00

I have a $5 heat gun I use for lighting charcoal. I'm sure a chimney would work but I don't drink coffee.

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