He/Him Jack of all trades, master of none

Proudly banned from lemmy.ml for being critical of the CCP

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Cake day: August 10th, 2023

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  • I use calipers and math to figure out how much filament is left on a spool.

    For example, think of the filament as one solid ring of plastic. My example spool is 60mm wide, the inner radius (of the filament, not the spool) is 28mm, and the outer radius is 40mm. Subtract the volume of the empty cylinder in the center from the solid cylinder of PLA, then multiply by 0.7 to account for packing density, and boom, you have a volume of filament that’s accurate to within a few percent. Convert that volume into cubic centimeters, multiply by 1.24, and you have a weight. This estimate gives my sample spool around 133 grams of filament.

    For a quicker, less accurate method, think of the filament as a collection of individual circles wound around the spool. My example spool is 60mm wide, so that’s around 34 strands of filament, and the filament is stacked 12mm deep, so that’s around 6 strands of filament (it’s safest to round down). 34x6=204, so the filament is wound around the spool 204 times.

    The average radius of one circle around the spool is probably 34mm (right in between the inner and outer diameters), so good ol 2πr gives us an average circumference of 213mm. 213mm×204 windings is around 43,500mm of filament, or 43 meters. Multiply by 3 grams (roughly the weight of 1 meter of filament). This estimate gives my sample spool around 129 grams of filament.

    It sounds very involved, but once you get the hang of it it’s very intuitive. You just have to know that

    • a circle’s circumference is 2π times the radius, or π times the diameter

    • filament weighs about 3 grams per meter of length


  • starman2112@sh.itjust.workstoLemmy Shitpost@lemmy.worldCheers Bro
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    8 days ago

    Tangentially related, you can also combine a basic knowledge of math with a basic knowledge of spreadsheets to make people think you’re the second coming of Einstein

    I shat this out in 5 minutes. All the white cells are user editable, and the blue cell calculates automatically. I could make it estimate annual gas costs by letting you adjust monthly mileage instead of speed and tweaking the math a bit. The average person would sooner close the application than try and make an interactive spreadsheet

    Edit: I made the annual price one. You can either use monthly mileage for a good estimate, or distance to work for a very rough estimate (it multiplies the distance by 2x260 (2 to account for round trip, 260 because there are 52 weeks in a year and every week has 5 work days))

    Of course it doesn’t account for non-work driving, but it also doesn’t account for holidays, so maybe it evens out

    For my turbonerds out there, I’m not sharing the sheet itself because my name is on it, but here’s the behind-the-scenes











  • Kinda, not really. In the wild, pigeons build their nests on cliffs, so they really only need just enough nest to keep the eggs from rolling off. That’s why they make dopey lil stick piles instead of proper bowl-shaped nests

    I’m not an ornithologist, so the following is my own uneducated hypothesis: pigeons haven’t adapted to live in cities, cities just mimic their natural habitats. They’ve survived this well because we’ve made great big terrariums for them