This is a sleeve for the spline drive socket adapter that is used with tuner lug nuts on aftermarket wheels. It keeps the steel socket from scratching up the lug nut wells on my shiny aluminum wheels.
In retrospect, it seems kind of ridiculous that I'd model this up and print it instead of just putting tape or Plasti Dip on the socket...
Update: I added a version with a base to make it easier to start the print and to give something to grab to pull it over the socket. It is also a proper model that will print with 2 perimeters with a 0.3 mm nozzle. I haven't printed a test yet, so if anyone does, I'd appreciate your feedback.
The model is a solid cylinder because I wanted to use "spiralize" and "outer mesh contours" in Cura 15.04.6 which in turn prints a single, nozzle-width perimeter with no top or bottom. It won't print a brim when those options are selected, so it's a little hard to get started, especially if the nozzle is drippy and doesn't start the first layer well. I reckon you could put the initial layer width to like 200% and maybe help overcome lack of prime or adhesion.
Additional Print Settings:
Filament: FoxSmart Screamin Green Flexible TPU
Hotend: 200 C
Bed: 70 C
Speed: 25 mm/s
Shells/perimeters: 1 (0.3 mm)
Top/bottom layers: 0
Nozzle diameter: 0.3 mm
Had to cut some slits around the base and use those segments to pull the thing on with needle nose pliers. Probably should add tabs...