
Although these days it would seem that everyone and their pets are running 3D printers to churn out all the models and gadgets that their hearts desire, a more traditional approach to creating physical 3D models is in the form of paper models. These use designs printed on paper sheets that are cut out and assembled using basic glue, but creating these designs is much easier these days, as [Arvin Poddar] demonstrates in a recent article.
The cool part about making these paper models is that you create them from any regular 3D mesh, with any STL or similar file from your favorite 3D printer model site like Printables or Thingiverse being fair game, though [Arvin] notes that reducing mesh faces can be trickier than modelling from scratch. In this case he created the SR-71 model from scratch in Blender, featuring 732 triangles. What the right number of faces is depends on the target paper type and your assembly skills.
Following mesh modelling step is mesh unfolding into a 2D shape, which is where you have a few software options, like the paid-for-but-full-featured Pepakura Designer demonstrated, as well as the ‘Paper Model’ exporter for Blender.
Beyond the software used to create the SR-71 model in the article, the only tools you really need are a color printer, paper, scissor,s and suitable glue. Of course you are always free to use fancier tools than these to print and cut, but the bar here is pretty low for the assembly. Although making functional parts isn’t the goal here, there is a lot to be said for paper models for pure display pieces and to get children interested in 3D modelling.
Paper modeling is about as inexpensive as a hobby can get. A huge variety of highly detailed models are available for free download. How about a 1/48 scale (2.3 m, seven and a half feet!) Saturn V? Or a 1/40 scale ISS that will probably need its own room for display…
https://www.papermodelingman.com/gallery_models.html
I remember papakura ages ago (10+ years?) as something I had to mess with to load and print a papercraft. I think there might have been paid upgrades to the viewer and the designer was 100% paid-only. It always struck me as the kind of thing that it would be pretty easy to write an open-source replacement for (just taking a 3D model and texture and choosing how to unfold it, then putting that on a sheet of paper to print), but I never had a strong enough need to pursue it.
Just this morning I built a model of a spherical flexure ( https://www.sciencedirect.com/science/article/pii/S0141635921000726#appsec1 ) out of cardboard with my kid. It didn’t turn out quite as accurate as the 3D printed one would have, but now I don’t have a bunch of single-use plastic to throw out.
And it felt a lot more like “doing” something than just waiting for a 3D print would have.