I found the HP glasses (Thing 94441) to be sized for very small children and inconvenient to wear since the hinges could open past 90 degrees. I used OpenSCAD to import and scale the design, added tabs to limit the hinges to 90 degrees and made the scale and the size of the hinge pins parametric.Use a short piece of filament for the hinge pins and you can "rivet" the ends of the hinge pins by melting them a bit against the side of your nozzle.I've found 1.25x to be the appropriate scale for most adults and 1.15x to be about right for children 8-12 yrs old.If you want to modify/customise the OpenSCAD file, download and save the HPV2_fixed.stl file to the same folder so that OpenSCAD can import it correctly.