N95 Mask Stretcher Ear Saver

thingiverse

As a large-headed hominid, I, too, suffer the indignity of having my ears' shear limit challenged by the too-short strands of elastic material included with commercially-sold (K)N-95 masks. I've tried the behind-the-noggin versions. An improvement for some, but I didn't find them satisfactory because they're difficult to don and slip down the neck, resulting in a vertical (instead of diagonal) load on the ears, which wasn't much better. Here's one that's better and uses less material (about 1 gram apiece) to print. The key is that it addresses the base problem (the string being too short) via internal loads rather than loading up your head. The critical design feature is the triangular ramp on both ends - these features automatically cinches the elastic band into the bottom face as the band tries to shrink back to its original shape. Steps: 1. Print these (no support. 100% infill, about a gram apiece). PLA is preferable due to its high stiffness. 2. Stretch the band and clip on the stretcher. First try 1-per-side. If your head is particularly large, you can do 2-per-side. I'm showing a 2-per-side installation in the above pictures to make the effect more salient. 3. ??? 4. No profit; this is a freebie. Yeah yeah I know the pandemic is over, but what about second pandemic?