Thanks for sharing - it was a fun read although I'd have a chat with the authors if I was the one reviewing it...
It's nice to see articles on 3D printing, but they've put so much additional fluff into the article, it looks like that "Sustainable Futures Institute" was breathing down their necks every step of the way. The only actual experiment here seems to be attaching an energy metre (of which the accuracy was not mentioned) to their printer and weighing the final object after the print. The rest is just some simulation software spitting out stuff to add pages to the document.
They make quite a few assumptions that also make their article look biased, making the 3D printing look as favourable as they can.
- They didn't say what they plan to do with the waste material from 3D printing
- It's not stated how exactly the conventional manufactured item was different from the 3D printed item: Sure you can reduce the infill on a printed product but not for a moulded one, but there are other methods in manufacturing that allow you to use less material.
- Water spout: They make it sound like you can't repurpose a 2L bottle to water plants without making that 3D printed part... (a tube and some putty?)
- They made the assumption that solar panels are free (how long will it take before the solar powered printer saves enough energy to make getting the solar panels worthwhile?)
- They made the assumption that 3D printers take no energy to construct and maintain
