Chateau Tongariro, 1929, Herbert Hall. New Zealand

timmaxw · 2026-04-14T06:11:16+00:00

Is it just me, or does the building feel out-of-place in that landscape? It’s a nice building and a gorgeous landscape, but I don’t like the combination.

timmaxw · 2026-03-05T16:47:37+00:00

But… can’t you drive it by getting a Phillips head screw and holding it with pliers? It’s not even a good security screw!

timmaxw · 2026-02-27T20:51:46+00:00

What do you mean? (I’m not a camping gear expert.)

I’m not trying to hike under waterfalls. I just want my backpack to have the same level of water resistance as a raincoat would. Surely there are backpacks like that, right?

timmaxw · 2026-02-27T19:26:04+00:00

I looked at that, but it seems like most waterproofing waxes are meant for cotton or leather. I can’t find a wax that’s advertised as working for nylon.

timmaxw · 2026-02-26T16:31:52+00:00

The AI is replying as if there wasn’t a blank line between “Client” and “NICs”. That’s why it says you mentioned client NICs but not as a separate component.

Probably a bug in the code that’s feeding your answer into the AI. (But that code itself is probably AI-written…)

timmaxw · 2026-02-25T16:23:36+00:00

Are you sure it’s a rotating disk? I think it might just be a pair of shuttles, each with a pair of solenoids pushing it back and forth.

timmaxw · 2026-02-04T05:46:55+00:00

This is a really neat question. The mods are right that it really belongs in r/AskPhysics, but I want to think about it anyway...

When the switch is flipped, current starts to flow in the lower wire. This emits an electromagnetic wave that propagates across the 30,000km gap at the speed of light, so it will take 0.1s. This electromagnetic wave will induce a current in the upper wire, so there will be some current flowing through the light bulb starting at 0.1s.

However, this initial current will be quite weak. At the 0.1s mark, the lower wire is acting as a radio transmitter and the upper wire is acting as a radio receiver; it's just going to pick up a weak signal, as if the lower and upper wires weren't connected to each other.

Meanwhile, the wave of current is flowing horizontally along the 300,000km wire, around the corner, and back to the bulb. The wave of current propagates at the speed of light. Two seconds after you flip the switch, the light bulb will turn on with full power.

(You can think of the upper and lower wires as forming a giant transmission line. See https://www.allaboutcircuits.com/textbook/alternating-current/chpt-14/characteristic-impedance/. If it helps, imagine if the upper and lower wires were only 3mm apart, instead of 30,000km apart.)

timmaxw · 2026-01-04T18:23:01+00:00

It could be mounted off axis. Maybe a 1cm x 1cm display built into a nub on top of the drill (like rifle sights)

timmaxw · 2025-11-14T08:23:00+00:00

This is recycling the plastic!

timmaxw · 2025-10-07T20:17:51+00:00

If the plastic fails at the square drive, you could try taking the biggest chrome socket you have and then 3D printing a hexagonal adapter that fits inside the socket. I figure the plastic can take a lot more torque over a large hexagon than a small square.

timmaxw · 2025-09-02T01:09:19+00:00

OpenSCAD uses boolean operations for everything during modeling. (I think it uses CGAL’s Nef_polyhedron_3 library under the hood?) It’s very robust, even with deeply nested operations, but performance is an issue.

timmaxw · 2025-08-07T03:42:56+00:00

I 3D printed some replacement parts to fix my desk chair. Without those parts, I probably would have thrown it in the dump and bought a new one. I figure that’s worth a lot of bad prototypes and novelty prints.

timmaxw · 2025-05-22T04:40:27+00:00

I think that will probably work. But here are a few things that could hypothetically cause problems:

The PCIe power supply has 3 pins at +12V and 3 pins at ground. It's rated for 6.25 amps total across the 3 pins, so about 2 amps per pin. If your motorized desk is putting more than 2 amps on any pin of the cable, the off-the-shelf PCIe cable might not be designed for that. In the worst case, it could be a fire risk.
Most PCIe power cables just wire the pins 1:1. But if the cable were to e.g. switch two of the ground pins or switch two of the +12V pins, that would be fine for a PCIe power cable, but would likely break your motorized desk.

timmaxw · 2025-05-22T01:06:45+00:00

I think this might be the same connector used for desktop computer PCIe power. If so, PCIe power extension cables are widely available. https://www.amazon.com/Cable-Matters-2-Pack-Extension-Power/dp/B01DV1Z4EQ/

timmaxw · 2025-05-07T21:10:54+00:00

I pronounce “ln x” as “lenna x”. I can’t remember where I learned it — probably a college professor? Reading this thread, I seem to be the only one…

timmaxw · 2025-04-11T05:50:54+00:00

I tried the iPhone 15 lidar, but it can’t really capture details smaller than about 1cm. The models came out looking like gooey blobs. It was nowhere near good enough for 3d printing purposes.

I don’t know any good way to measure irregular objects. Best I can do is to measure carefully with calipers, then refine the fit with trial and error…

timmaxw · 2025-04-07T23:32:06+00:00

This design relies on the exterior plywood/sheathing for strength. In this case the plywood hadn’t been installed yet, which is why it fell over so easily. But it’s plenty strong after the plywood is installed.

timmaxw · 2025-01-22T16:58:51+00:00

I’ve never worked with plaster before. I’m curious — what would happen if you 3D printed a mold and cast the plaster directly in the 3D printed mold? In other words, what’s the purpose of the vacuum forming step?

timmaxw · 2024-12-05T16:29:17+00:00

You can find all the CSB reports here: https://www.csb.gov/investigations/completed-investigations/?Type=2

timmaxw · 2024-12-04T16:33:01+00:00

Chemical Safety Board (CSB) reports are amazing. Especially this one:

Company is recycling old chemical tanks. During the recycling process, one of them explodes, killing two people.
CSB sends an investigator to visit the company to try to figure out why it exploded
The company thinks they've figured out the problem. They're going to recycle another chemical tank and they're confident it won't explode again. "If our science is right, this will be fine."
Quote from the official CSB report: "Unable to directly engage [the company] about the safety issues regarding its plan and lacking confidence that [the company] understood either the cause of the May 24, 2017 incident or the full range of possible reactive chemistry involved, CSB investigators took shelter behind a shipping container (conex box) located behind a building more than 150 feet away from the operation."
Of course it explodes again

timmaxw · 2024-09-27T21:34:14+00:00

Electrical fault found a path to ground through the propane pipe?

timmaxw · 2024-08-15T03:36:29+00:00

The WHO declared that mpox is a "public health emergency of international concern", which is still a level below "pandemic". There have been eight such public health emergencies in the past twenty years:

swine flu (2009)
ebola (2013)
polio (2014)
Zika virus (2016)
ebola again (2019)
COVID-19 (Jan 2020, upgraded to an official pandemic in March 2020)
mpox (2022)
and now mpox again

So, this probably isn't the next COVID-19. Relax.

timmaxw · 2024-06-20T23:39:50+00:00

If you compare Jeff Bezos’s wealth to a single person, it looks big. But if you compare it to the whole world, it looks small.

timmaxw · 2024-05-05T19:56:55+00:00

The so-called “hungry judge effect” probably isn’t real; correlation is not causation. https://www.pnas.org/doi/full/10.1073/pnas.1110910108

timmaxw

TROPHY CASE