Stethoscope - Single Patient-Disposable

thingiverse

Posting this to share my remix of the Glia Project's GliaX Stethoscope. Mainly to share additional sources for items that I had to track down, which were easily available on Amazon, as well as to share my remixes of parts that I modified based on the resources available to me. Background My wife works in a hospital and last week she came home and announced that they were looking for help making disposable 3D printed stethoscopes. I did some Google research on 3D printed stethoscopes and found the Glia Project. Having already donated a large number of face shields to the hospital, I had a supply of PETG on hand. From other projects, I also had a few meters of tubing that was a pretty good match and some plasticard for doing prototype runs. Even without all the right components, I was able to make a pretty darn good prototype, good enough to order some real supplies and offer up my services to the hospital. For the original release of this thing, I remixed a single part needed to ensure functionality. There are a couple other changes I'd like to make, but the hospital has mentioned that they're happy with the current version, so I'm not going to push for those changes right now. The first remix I did was to modify the ring part to accommodate the thinner diaphragm. One of the most challenging parts to find was a report cover with the correct thickness (since thickness isn't really a critical dimension on report covers, those numbers aren't advertised). Since I'm in the US, I don't have access to the Canadian-only Staples part listed (others have mentioned this issue also). I found what appears to be a very similar item and ordered it. The problem was that it is only 0.2-0.25 mm thick. This resulted in the diaphragm being slightly loose in the head because the outside of the ring reached full depth on the head before the diaphragm was clamped firmly against the spacer ring printed on the top of the head. A simple Z scaling would have resulted in the face of the ring being only 1 layer thick. Hence, the remix here of that part. It was re-drawn from scratch with dimensions ensuring that there would be at least 3 layers in the face of the ring and having the sidewall being 0.5 mm shorter. This change allows the thinner material to be clamped firmly in place and provided a significant improvement over the loose version. Update 24 Jun 2020 - New remixes 1 - Update to Ring (v8) - Found that depending on the filament brand used, I would occasionally still get a loose fit of the diaphragm. So the latest version reduced the sidewalls by another 0.5 mm. IT IS CRITICAL that the ring hold the diaphragm tightly to the spacer on the top of the head. If the diaphragm is loose, the stethoscope will not work. 2 - We found that the original spring design was moderately stiff and somewhat brittle when printed in PLA. Additionally, as stated in some of the comments on the original design, it was somewhat difficult to get the ear tubes aligned and installed into the spring. The remix of the spring reduces the thickness of the middle of the spring making it somewhat looser and significantly less prone to fracture if printed in PLA and flexed to a straight line. The holes for the eartubes were also adjusted to ease assembly. Although this remix was specifically tuned to work with the new ear tubes, the original ear tubes will also work with it. It also prints in 1/2 the time as the original. 3 - The blunt ends of the original ear tubes made it very difficult to get the 4 mm ID tubing on them. The remixed ear tubes have a much longer bevel on the end where the tubing goes making them MUCH easier to assemble. However, there is now a support built into the new version to support the longer bevel that must be removed before assembly. I also removed the large tabbed raft at the ear end of the tube and replaced it with a smaller one to save space. This little raft also needs to be removed before putting on the ear buds. 4 - Remixed the Y to remove the rafts for space savings on the build plate. Also optimized the wall thickness to be a multiple of 0.4 mm. Proposed Additional Remixes 1-Fillet head for easier removal from build plate (2 mm radius) - *Still haven't remixed the head* 2-Remove tabs from parts for easier removal from build plate. They may have been needed for the original ABS parts and the Mk2 build plate, but I don't think I need them for my Mk3 with the PEI plate and they are VERY hard to remove. - *DONE*