Orthodontic Expander Key

thingiverse

From the "Don't try this at home kids" department.... My daughter had an orthodontic expander, but she lost the key yesterday. The orthodontist is closed for the week, and she needs to have it cranked every day. I happened to have some stainless steel hex keys, so I made a prototype by bending one at an angle (see photo) and it was successful. Then using FreeCAD, I designed a more elaborate tool as shown here. The blue and white tool in the photo is what I'm replacing with a 3D printed version. After printing, I'll cut down one of the hex keys and press fit it into the hub. As soon as the glue dries, I can snap the yellow pieces together, and it will get used for at least a few days until the next orthodontist appointment. On Saturday, I had a successful use of the home printed version, then on Sunday my daughter found her original key so we went back to the OEM version. It was interesting to compare mine as printed with the OEM version - one feature lacking in mine was a little jog in the business end that keeps it from going in too deep and potentially scraping the roof of her mouth. Dimensionally otherwise, my version was pretty close to the OEM version. The verdict: successful experiment.