A large fingerboard spinner obstacle. This design prints in four pieces and uses a standard skateboard bearing. The rail is friction fit or you can glue it in place.  The shapes are simple, as this is my first attempt at designing with Tinkercad. I'm starting to get the hang of it. The top and ramp are meant to print upside-down for a better, faster print with smooth skateable surfaces. The ramp and base are shells rather than solid shapes to help reduce filimaent wasted. The design is also fun I think. You hit the rail, stall and spin then exit off the ramp. Gnarly dude!

Edit:  The ramp was too much of a shell, the walls weren't thick enough to provide any friction. I've made some adjustments to make the ramp have more surface area on the bottom. 

This object was made in Tinkercad. https://www.tinkercad.com/things/2A5BwcvyjP1