zipsglacier

joined 2 years ago
[–] zipsglacier@lemmy.world 2 points 19 hours ago (4 children)

First time I ever heard the speech was on this amazing album: https://theotolith.bandcamp.com/album/folium-limina

[–] zipsglacier@lemmy.world 10 points 2 days ago

Excellent fact, and bonus points because the fact is only recorded in a footnote of a writeup about an already moderately obscure fact.

[–] zipsglacier@lemmy.world 6 points 2 days ago

This is right, for as long as the fdm printer hobbyists can avoid the lockdown and enshittification that some printer brands are definitely pushing. The value of this paper, for it's authors, seems more like a proof of concept: fingerprinting is possible. And I think that's actually it's same value for hobbyists: the problems with a closed system and proprietary printer firmware are not hypothetical.

[–] zipsglacier@lemmy.world 10 points 2 days ago (2 children)

The fact that this could only work in 100% locked down ecosystems was my thought too. About cutting the part up, that seems to be what this particular paper is most proud of: they did a bunch of math to make some codes that they could still figure out even when they were cut into pieces and mixed up---like if a person broke their printed part after using it. Sort of like error-correcting codes I guess, but able to be reassembled from fragments.

[–] zipsglacier@lemmy.world 25 points 2 days ago (11 children)

Here's the paper where they explain it. Basically, they make subtle fluctuations in layer height, adding or subtracting small amounts that are not visible to the naked eye, to encode 0s and 1s. So, maybe in principle this could run at the firmware level on your printer. Then, someone can use a microscope to read off the code from pieces of the printed part.

I would have some doubts about how reliable this is, given the relatively large tolerances in fdm printing, but they have a section about that in the paper, so I guess they at least have thought about it.

 
[–] zipsglacier@lemmy.world 10 points 2 days ago (4 children)

Here's the paper where they explain it. Basically, they make subtle fluctuations in layer height, adding or subtracting small amounts that are not visible to the naked eye, to encode 0s and 1s. So, maybe in principle this could run at the firmware level on your printer. Then, someone can use a microscope to read off the code from pieces of the printed part.

I would have some doubts about how reliable this is, given the relatively large tolerances I fdm printing, but they have a section about that in the paper, so I guess they at least have thought about it.

[–] zipsglacier@lemmy.world 5 points 1 week ago

How do I reblog this

[–] zipsglacier@lemmy.world 5 points 2 weeks ago

For those who haven't seen this amazing interview:

https://youtu.be/urcL86UpqZc

[–] zipsglacier@lemmy.world 3 points 3 weeks ago

Yep. If it's 9:22:45, then rounding to 9:23 is more accurate than 9:22 anyway.

[–] zipsglacier@lemmy.world 3 points 4 weeks ago

This thread is like the Simpsons gag blowing dust off the book title "How to cook [for(ty)] humans", except everyone's an asshole and I also learned several things. Upvotes all around!!

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submitted 1 month ago* (last edited 1 month ago) by zipsglacier@lemmy.world to c/3dprinting@lemmy.world
 

I've been experimenting with foldable 3d prints for tall thin walls in some game organizers. (Bigger pictures below.) The principle here is sort of similar to a living hinge, but not designed to flex too many times. Just fold once and be a reasonably stable structure.

Here are some individual pictures of the designs I've made, for corner support of some game organizers. Below, I have explanation and the design/dimensions that I use.


Overview

I haven't seen this type of design too often before, so I thought I would share what design and dimensions worked for me. Here is an overview:

  1. I design what I call the Wall as an outline, with some cutouts to reduce material. This is the part that prints flat and will fold up.

  2. I apply a chamfer to all edges, to help with removal from the build plate.

  3. I make a Y-Profile for the fold line grooves. The profile is vaguely Y-shaped, with a short rectangular base and an angled top. (Picture below; the Y-profile is labeled "cut out groove" there.)

  4. I use the Y-profile to cut away material from the wall to make those grooves.

  5. I print these in PLA (the pictures are matte PLA, because that's what I had). I guess PETG might be more sturdy, but honestly the PLA was so good that I haven't bothered with PETG.

Here is a picture, which I'll explain below.


Design Details

The top of this picture is an edge-on view of the wall (green horizontal lines) and the Y-shaped profile (labeled "cut out groove"). I use the following dimensions:

  • wall thickness: 1.5mm
  • wall chamfer (not pictured): .5mm
  • Y-profile base height (a): 0.3mm
  • thickness remaining below Y-profile (b): 0.4mm
  • angle of Y-profile sides: 40 degrees from horizontal (45 didn't fold as well)
  • Y-profile base width: (pi/2) x a x 1.1 (=.52mm with other dimensions above)

That last measurement, the width of the Y-profile base, is what the bottom part of the picture is about. The key idea is that width is going to be, roughly, 1/4 the circumference of a circle with radius a. So, I computed that amount, and multiplied by 1.1 to give 10% extra width.

With these dimensions, the part that folds is 0.4mm thick (dimension b in the pictures), then there is a 0.3mm clearance (dimension a), and the two arms of the "Y" fold together. In my first trials I used 45 degrees for the Y arms, but found that I got a better fold making them a little wider (so, lowering the angle from horizontal, to 40 degrees). This basically gives a little extra tolerance for variations in the physical print.


Conclusion

I hope this helps someone! I think it's a neat technique, and I'm a little surprised that I haven't seen it used anywhere else. I've seen various designs for living hinges, which are roughly the same principle, but designed to flex repeatedly. Searching around, I found one foldable cube on thingiverse. But otherwise I haven't found any models using this kind of design.

 

The plastic part inside this latch broke, and I wanted to print a replacement. I was genuinely surprised at how straightforward it was!! This is my first draft: it fit and worked fine! I made a second version with a few cutaways around the corners, and that was the final draft. (I forgot to take a picture of that one.)

There are lots of awkward overhangs, and I was having a hard time figuring out how it could be printed (a) in a good orientation for the stresses and (b) without supports. Then I remembered: we can just use supports!! I usually try to design so that they aren't needed, so I almost never use them. But wow they made this easy.

 

For anyone interested in checking this game out, but daunted by the very large card pool, this article is pretty good. The goal is to give people suggestions without triggering FOMO over stuff that's out of print or way too expensive.

I think it does a good job. Maybe too good: there is still a big wall of text. The core recommendations, which are accompanied by a lot of additional explanation and alternatives, are the following.

  1. There is not a single [expansion] for this game that you NEED to enjoy what is available. Even if you never lay your hands on [some particular expansions], you will still be able to have a great experience. Your cardpool will be excellent and you will be able to play great campaigns.

  2. You do need a Revised Core Set; the box labeled FFGAHC60, from 2021. That box has everything you need to play the game and see if it's for you. Many of the cards in that box are still regularly used by experienced players---the core set is very good.

  3. First investigator expansions: Edge of the Earth or Drowned City, or [other discussion].

  4. First campaign expansions: Drowned City or Innsmouth Conspiracy, or [other discussion].

  5. Is this game for you!? This is a good question, and there is some discussion of it at the end of the article.

 

I've been waiting until the alpha release to try cosmic, so I haven't paid much attention to instructions for installing it alongside my current pop os 22.04. Now that the alpha is out, I see all instructions pointing to download and install the 24.04 alpha iso. But, that's a big hassle! Is there a way I can try the cosmic alpha along side my current install?

 

My teenage son wants to try a new distro for gaming. Our family has been using pop os for years, but he wants to try something new. The main three I see are

  • nobara (fedora based)
  • garuda (arch based)
  • drauger (ubuntu based)

The machine he's using is a 2018 Intel nuc. It has a strong processor (core i7) but no discrete graphics. I can't tell which (if any) of the distros above would be better or worse for his case.

Reading around, it seems like Garuda might be slightly more fiddly. And, Drauger I only saw mentioned in a couple of articles, but not on this forum. Are these impressions correct? Do you have any other advice for us?!

 

I press Super and type "recent " to open some documents. But after reorganizing where some of them are stored, I now see entries for both the new and old locations. Currently the old ones are at the top of the list, because I've used them more often. Choosing those entries doesn't do anything, because the paths don't point to those files anymore. How can I remove the old entries from the list?

 

If only there was some way I could have known to try this sooner! /s

Story: I wanted to try printing with petg, since I've read how much easier it is. But with a new roll I just had a really hard time. Lots of stringing, poor adhesion, and it just seemed like no amount of my usual fiddling would really make it better.

Somewhere I read that even new filament can benefit from drying, because maybe it wasn't stored in the best way, or maybe it's older than you think. I also read about putting the roll on the print bed, heating it up and covering it for a long time, since I don't have a filament dryer. I did that for about half a day, and then sealed the roll in a ziptop bag with a silica packet because I needed a break from it. A week later and, it seems much better!?

Either the drying, the break, or something else seems to have helped a lot! Happy printing everyone.

 

Last time I looked for how to do this, hydrapaper seemed to be the best option. Lately though I get a warning every time flatpak updates.

Info: runtime org.gnome.Platform branch 42 is end-of-life, with reason:
   The GNOME 42 runtime is no longer supported as of March 21, 2023. Please ask your application developer to migrate to a supported platform.
Info: applications using this runtime:
   org.gabmus.hydrapaper

Is there something else people are now using? Or are they staying with hydrapaper (it seems to still work fine)?

 

In the eyes-box!

 

I needed a reminder of where to look, and the first search result was in a reddit post on r/pop_os with a similar title. Since that sub is currently locked, I found my answer elsewhere. I decided it would be useful to post the info here too. I'll write my answer below, and someone can write a better one if they have it.

(p.s. Thanks for keeping the reddit sub private; I think it's the right decision since the major reasons for the blackout have not changed.)

 

Anyone have any good suggestions? Educational stuff is good, but I'm also interested in other games that kids can play solo or with parents. (We're a PC gaming house, but I'm open to suggestions for any platform.)

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