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Progenitor of the Weird Knife Wednesday feature column. Is “column” the right word? Anyway, apparently I also coined the Very Specific Object nomenclature now sporadically used in the 3D printing community. Yeah, that was me. This must be how Cory Doctorow feels all the time these days.

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Joined 3 years ago
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Cake day: July 20th, 2023

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  • Both of my Qidi machines have been plug in, load filament, and print. My current X-Max 3 also provided a rather polished out of the box experience with an on-screen guide and everything. I would much rather have a Qidi than any Bambu machine at this point.

    I’m a little disappointed that they’ve apparently recently abandoned their homegrown fork of Prusa Slicer in favor of a home grown fork of Bambu’s slicer, but here’s hoping Bambu’s current litigious fuckery will cause them to rethink that strategy. Still, their stuff is open source enough that there’s nothing stopping me from using any other slicer with it if I felt like it. Or, indeed, any other firmware.



  • Yes. And I suspect due to its low temperature resistance (this an intuitive guess; I’m not exactly a materials science engineer) it also exhibits very poor cold creep/permanent deflection characteristics. ABS is actually the best of the bunch there, probably hand in hand with ASA.

    However, one thing people are often surprised to learn or discover about boring old PLA is that it actually has among the highest layer adhesion strength of the commonly available materials, I believe second only to polycarbonate, and it’s also the most rigid of the commonly available (non-filled) materials. At least at room temperature, anyway. It turns out that printing the screws for e.g. my Rockhopper or Adélie in anything but PLA amounts to being a fool’s errand.

    It’s tempting to think of the litany of plastics available in filament form to consumers as a simple linear and escalating spectrum with “cheap, flimsy, easy to print” and one end and “expensive, strong, difficult to print” at the other. In reality as you know it’s not quite so simple. If anything, the hypothetical graph describing the properties of PLA, PETG, PET, ABS, ASA, Nylon, polycarbonate, etc. would have to be three dimensional.


  • That’s because everyone starts with PLA, and PLA has the lowest shrink and warp of all commonly available materials… which is why it’s so common and everyone starts with PLA.

    Basically anything is going to warp more and compare poorly against PLA, but ASA’s shrinkage after cooling is less than half of ABS, so it compares favorably to ABS in particular. 1.6% vs 0.7% or something similar. PLA’s shrink rate, meanwhile, can be as low as 0.3% for competently manufactured blends. Shrinking while cooling is what causes warp, especially on broad flat objects.





  • Be careful of what, spontaneously learning to fly? I’m still trying to wrap my head around what possible sequence of events could have led to hooking that bike by its forks on the pole like that while apparently causing very little damage to it in the process. Okay, he’s knocked off the front fairing and the windscreen, if it had one. But both tires are still inflated, the frame appears straight, the lower splitter is still attached, and I don’t even think the fork tubes are bent.

    Just.

    How?