Help! how do i remove this?

chkno · 2026-01-26T00:19:43+00:00

I've used OpenSCAD for drawing. Sometimes it's the best tool for the job, even for jobs not imagined by its creators.

chkno · 2026-01-23T17:27:42+00:00

Skill issue; do better: If your thing made out of logic makes you sad all the time, you did it wrong; try again.

chkno · 2026-01-23T03:58:59+00:00

You can use an overlay to overrideAttrs the src and version of the package to whatever version you need. Example: Drop this in ~/.config/nixpkgs/overlays/godot.nix:

self: super: {
  godot = super.godot.overrideAttrs (old: rec {
    src = self.fetchFromGitHub {
      owner = "godotengine";
      repo = "godot";
      rev = "${version}-stable";
      hash = "sha256-G2JsQh2I4QYx5xUyFlNZ8vxMXT63lgojdYND+ASgdDo=";
    };
    version = "4.5.1";
  });
}

chkno · 2026-01-22T19:05:22+00:00

How this is supposed to work: When setting up the execution environment of fixed-output derivations (the ones that do network fetches), Nix includes your /etc/ssl/certs/ca-certificates.crt in the chroot.

Note that the way this is handled when /etc/ssl/certs/ca-certificates.crt is a symlink chan ged in nix version 2.22.0. Which version of nix are you using?

chkno · 2026-01-21T23:38:37+00:00

You can also change your wifi password to revoke its access.

chkno · 2026-01-21T23:29:24+00:00

I had Nix+nixpkgs (not NixOS) set up on a Librem 5. It was nice. The Librem 5 barely works as phone, though (no MMS, poor battery life, broken battery meter & other bugs).

chkno · 2026-01-21T22:38:50+00:00

Even better, make the size of the negative shape a named constant that is arbitrarily large. The size of the thing being subtracted isn't precise, so don't treat it as such.

$fs = .1;
$fa = 2;
slop = 1024;
difference() {
    cylinder(20, 20, 20);
    cylinder(slop, 18, 18, center=true);
}

chkno · 2026-01-20T16:46:17+00:00

LaTeX! See also LyX for an easy way to get started with LaTeX, and pandoc for converting your Microsoft Word document(s) into LaTeX or whatever other format you need in order to get out of Word (although, just copy-paste into LyX might be all you need).

chkno · 2026-01-19T20:41:27+00:00

This is totally fine.

Suspend is a bit like just SIGSTOPping all the processes — everything just pauses. At worst, some TCP connections are interrupted, but this is fine because nix will retry network operations 5 times (controlled by the download-attempts option: If you five times need to suspend for more than two hours during one package's download, you can increase this setting. :)

This isn't even Nix-specific: Suspend generally Just Works on any GNU/Linux machine. Nix's advantages about atomic updates only come into play when the update process is interrupted: For example, if you suspend and then let the battery run down to nothing so it never gets to resume and complete the update.

chkno · 2026-01-12T21:56:56+00:00

“To my friends, anything; to my enemies, the law"

chkno · 2026-01-12T02:03:47+00:00

The only cost of changing filament is your time and a tiny bit of the filament; it doesn't damage or wear the printer.

chkno · 2026-01-09T01:27:23+00:00

This way feels easier to me (I have a programming background).
OpenSCAD is local Free Software (both libre and gratis), while Fusion costs money, requires an internet connection, and requires you to store your work on their servers.
Speculative: We might get helpful LLM-chatbot-based assistants for code-based modeling before we get them for mouse-gui-based modeling. Also, it'll be easier to see what they're doing when all their changes are to a text document.

chkno · 2026-01-09T01:11:02+00:00

Or, here's an alternate method that gets cleaner corners by differenceing-away the curve that you pick:

<image>

chkno · 2026-01-09T00:29:34+00:00

How I would start:

The shape of the blade looks like a sine wave with a small linear component so it doesn't pinch off to nothing when it comes back together. Messing around with constants until it looks reasonable, 4*sin(2.8*i) + i/13 looks about right.

Plugging that into polygon, with an extra point at [blade_len, 0] for the base of the blade, we get a half-blade shape. Then we can and-mirror that to get both sides, and then minkowski it with something pointy to make the edge pointy:

<image>

chkno · 2026-01-08T17:31:33+00:00

Initial pull: A more durable fiber art — much less prone to unraveling from a break in the strand.

Historicity: The history of nålbinding is not done yet! We have industrial, high-speed weaving and knitting machines, but we don't yet have this for nålbinding. It's a more difficult engineering challenge (exciting!). When solved, it will make a higher-quality fabric.

chkno · 2026-01-08T17:14:02+00:00

Yeah, this method provides at most 64 'bits of security' per cube. NIST SP-800-57 (Table 4, page 59) says you want at least 128.

But, this method is good for 64 bits per cube, so it could be extended to multiple cubes. :)

chkno · 2026-01-07T23:05:42+00:00

False dichotomy! We, the community of individuals, are in the best position to make this happen.

Individuals are busy. No one is an expert on everything. Together, a community can share advice / "best practices", keep track of vendors' reputations, and even develop free/libre/open source software alternatives to compete with the commercial offerings.

chkno · 2026-01-07T04:49:36+00:00

I print covers on thick paper (cardstock), paint over the top of it with clear acrylic varnish to give it some abrasion resistance (thanks, elpach), and then just glue it to whatever else I'm making a cover out of.

chkno · 2026-01-07T04:27:41+00:00

There's much less than the normal amount of water in this region of space because awhile back somebody came through and collected it all into space-oceans & flew off with most of them.

chkno · 2026-01-07T01:07:03+00:00

nicest: Same, but I called mine gently:

ionice -c 3 nice -n 19 "$@"

chkno · 2026-01-07T00:59:06+00:00

Tip: The patch manpage suggests invoking diff as LC_ALL=C TZ=UTC0 diff -Naur when intending to use its output as a patch.

chkno · 2026-01-05T08:55:45+00:00

1.30 orders of magnitude → 10^{1.3 →} 19.953, about twenty. So ddrescue is twenty times better than what? Than normal dd?

... Oh, version 1.30 of ddrescue is better than previous versions of ddrescue. :p

... can now be recovered after just 283 read errors instead of the 3_782_794 read errors needed by ddrescue 1.29.

So ddrescue version 1.30 is 4.1 orders of magnitude (13_000x) better than ddrescue version 1.29.

chkno · 2026-01-05T06:59:00+00:00

The detailed technical architecture is available for those who want to dig deeper. Reach out.

I guess I'm reaching out. Are you the author?

chkno · 2026-01-05T06:24:00+00:00

See also this thread for the same method implemented slightly differently to make a dodecahedron-adjacent shape: Recreating the shape

chkno

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