NMR Tube Carriers
I really enjoy designing 3D models, and I really don't like filling out near-miss paperwork.
I've been designing and re-designing NMR tube carriers for literal years now, and I think I finally have a set that I like. Check them out on Printables.
At my last job, there was a strict rule about carrying NMR tubes around in mixed-use hallways. If you dropped one and it shattered, or it broke in your pocket, you'd have a potentially-flammable, potentially-toxic spill in an area where people don't wear gloves or goggles. It's a small risk, in the end, but no safety person ever got fired for suggesting an annoying fix to a minor safety concern. And they will scold you while you fill out a pile of paperwork.
I didn't like the carriers that work supplied – mostly that they only held one tube. So I designed and printed a carrier that held multiple tubes. That brought me into my favorite part of 3D printing: the loop of designing, printing, evaluating, and redesigning. It took a while, but I think they're ready.
At my current job, we have a group that routinely brings 15+ tubes down to the NMR lab at a time. So, I designed a huge one that carries 19 of them in a nice, space-efficient hex pattern. I could go up by one more 'ring' of tubes, but I think it would take half a kilo of filament to print. The single-tube carrier is probably what everyone needs. A 3-tube 'small' version is an upgrade. I use the 7-tube 'medium' version, but I'll never fill it up in one trip. And the enormous 19-tube carrier is enough even for the edge-case users.
It's really fun to build cool stuff and put it out into the world.