3 ms·

Density of PETG (a reasonably durable and temperature-resistant plastic that's much easier to work with than ABS or nylon) is around 1.25 g/cm3 IIRC. Compare th

Density of PETG (a reasonably durable and temperature-resistant plastic that's much easier to work with than ABS or nylon) is around 1.25 g/cm3 IIRC. Compare that to wood (pine at around 0.4 ~ 0.5 g/cm3 or maple (~0.7 g/cm3). For the plastic structures to be sturdy, they have to be printed with significant infill, or at least painstakingly designed incorporating familiar structural elements (triangles, i-beams, gussets etc) at 100% infill -- in either case, making them as heavy or heavier than a comparable wood structure. I doubt the "lightweight" claim here. I get the "throw robots at the problem" idea, but you could similarly automate the process with CNC machines and thin wood panels. I have some experience in working with both types of materials, and in most cases, design turns out to be the most challenging and time-consuming part.

jauntywundrkind 2y ago
1.25g x 0.6 fill % (very high % / generous in my view) is still 0.75g, on par with a hard wood. But density to me is not what I'd look at. If you could have something twice heavy but that was 100x stronger as a structural material, that obviously would be an epic win. Maybe it's less dense, but a lot of van builds use a lot of 2x4's or other fairly bulky wood. My hope is that the volume of the structure is much much less with good 3d printing. Building a layer cake of cc'ed thin wood panels would probably work, sure. It feels like a specific skill, a specific technique. Part of what's neat about 3d printing is that the manufacturing skills are transferable, that you can laterally apply it quickly to all kinds of problems, without trapping with a specific set of constraints (additive wood paneling requiring some CNC skills, some gluing/affixing panel skills). I get the appeal. Design can be a perk. That people can shape their own ideas & forms is an enticing offer. We struggle right now to imagine our 8 year old with a metaball editor like truSpace designing our camper vans or our house furniture. The barrier isn't low enough. But I think there is a joy people would have widdling and carving & nudging the forms in the world about them. We don't really have the open design systems to play freely yet; that hinders the creative flow suggested by this article. Especially if we can just throw our bench into the hopper and rebuild it (after 4 days of printing, lol), and with some solid starting places & high level editor software (VR painting, anyone?), some people would relish being able to craft their world. Design can be a joy.
- slau 2y ago
  I’m struggling to see why infill would need to be over 30%. I thought it was fairly well known that increasing infill does not significantly increase strength. More perimeters definitely do help, so maybe that’s what it being referred to (within the context of very thin panels)?

jauntywundrkind 2y ago

1.25g x 0.6 fill % (very high % / generous in my view) is still 0.75g, on par with a hard wood. But density to me is not what I'd look at. If you could have something twice heavy but that was 100x stronger as a structural material, that obviously would be an epic win. Maybe it's less dense, but a lot of van builds use a lot of 2x4's or other fairly bulky wood. My hope is that the volume of the structure is much much less with good 3d printing. Building a layer cake of cc'ed thin wood panels would probably work, sure. It feels like a specific skill, a specific technique. Part of what's neat about 3d printing is that the manufacturing skills are transferable, that you can laterally apply it quickly to all kinds of problems, without trapping with a specific set of constraints (additive wood paneling requiring some CNC skills, some gluing/affixing panel skills). I get the appeal. Design can be a perk. That people can shape their own ideas & forms is an enticing offer. We struggle right now to imagine our 8 year old with a metaball editor like truSpace designing our camper vans or our house furniture. The barrier isn't low enough. But I think there is a joy people would have widdling and carving & nudging the forms in the world about them. We don't really have the open design systems to play freely yet; that hinders the creative flow suggested by this article. Especially if we can just throw our bench into the hopper and rebuild it (after 4 days of printing, lol), and with some solid starting places & high level editor software (VR painting, anyone?), some people would relish being able to craft their world. Design can be a joy.

slau 2y ago
I’m struggling to see why infill would need to be over 30%. I thought it was fairly well known that increasing infill does not significantly increase strength. More perimeters definitely do help, so maybe that’s what it being referred to (within the context of very thin panels)?