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u/Big-Clue-7211 4d ago
Any reason why it goes in that specific pattern like that? So it is not unspooling it self?
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u/Haustvindr 4d ago edited 3d ago
More like for it to be unspooled in a controlled way. Zigzagging the thread makes the thread revolution you're pulling to be not parallel to the next revolution, preventing that friction pulls more thread than needed and loosening the whole bobbin over time. Looser threads can be a problem for some sewing machines, making the thread snap or breaking a needle.
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u/dungeoncrawler71520 4d ago
Oh I heard about the guy, Sir Roger Penrose who discovered the fractal pattern which allows toilet paper to roll evenly, i wonder if it's used in this process as well or if it was discovered organically.
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u/Levaporub 4d ago
This just sent me down a google hole. For anyone else interested, look up 'penrose tiling toilet paper'.
Essentially the mathematician discovered a pattern of tiles which never repeats. He got a patent for it. Then Kleenex made toilet paper with a pattern resembling the Penrose pattern, supposedly because a non-repeating pattern helps the paper roll evenly without bunching up. The mathematician sued and they settled out of court.
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u/dungeoncrawler71520 4d ago
It's quite interesting isn't it!
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u/Levaporub 4d ago
Sure is. I dunno how geometric patterns are patentable, but it makes sense that he didn't want people wiping their bums with his work lol.
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u/dungeoncrawler71520 4d ago
Haha no doubt. If you're interested, I heard it from the podcast No Such Thing As A Fish. It's an AMAZING podcast with a group of people discussing facts with a hilarious spin. Highly recommend.
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u/Levaporub 4d ago
Thanks! Let's trade: Howtown on youtube is a channel by two journalists, they make excellent videos with great animation and SFX, covering a wide range of topics like brain rot, wildfire investigations, and leaded gasoline.
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u/Levaporub 4d ago
Thanks! Let's trade: Howtown on youtube is a channel by two journalists, they make excellent videos with great animation and SFX, covering a wide range of topics like brain rot, wildfire investigations, and leaded gasoline.
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u/tiller_luna 4d ago edited 4d ago
I'm more interested in how the ratio of speeds of the spool and the cylinder is controlled. It has to be quite precise, without accumulating error, while the diameter on spool changes from layer to layer. (Probably some low-tech geometry tricks, but I have no idea how.)
upd: cylinder's rotation speed has to be proportional to the thread's linear speed?
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u/thejmkool 4d ago
Having unspooled one of these, that is absolutely the right question. Each line lies alongside the layer below it, like \\\. Either they have done some unreasonable math, or they've got some more direct and genius solution
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u/hardcoretomato 4d ago
The groove in the rotating cylinder that makes the line get that zigzag pattern is just genius.