I’m looking for a little help. I have a neighbor who is a nurse who works with COVID-positive patients. I’ve provided a few hundred ear savers for her department, and now she has a new problem: The disposable stethoscopes they are issued for working with COVID patients function poorly and are small, forcing close contact.
It turns out that there has been formal medical research into 3D printed stethoscopes, and she found this project that she asked me to help her try out for her unit:
This is a mash-up of the business end of a mostly-3d-printed classical stethoscope with an adapter for a microphone, and Android and iOS apps to listen and look (thus a stethogram).
It wasn’t too hard to print. It has to be 100% infill for acoustic reasons, so I had to tweak flow to avoid over-extrusion. But now the difficulty: It needs a precise 40mm circle of report cover material (the same thing we’ve been using for face shields) as the drum of the stethoscope.
I’m trying to figure out how to cut a precise 40mm circle without paying $125 for a punch, and without using a compass and putting a pinhole in the middle of the diaphragm for the drum.
I’d love ideas on how to cut out this nice precise 40mm hole. 1.5" punches are cheap in the US, but that’s 38.1mm; too small. So 40mm punches apparently have to be imported from Japan.
There has to be a better way!