Demo and assembly guide: https://youtu.be/5G4Wwa94_aM Exploded view in 3d viewer: https://skfb.ly/6QL8R Extra parts needed: - Nitrile glove - Air balloon Takes 4m of filament to print (about 5h at 20mm/s on my snail of a printer). Will print a bit prettier with supports (80deg. overhang, touching buildplate) and ironing. Parts with names starting with "X_" are optional. - You can insert one balloon into another to get thicker walls. Meant for 2-walled balloon. Idles well with one (with a flywheel), but will hardly pull any vehicle. - You can use metal M5 washer instead of printed one - Found that PLA isn't the best material for the design: isn't very slippery, and "fluid" (the clips stop pushing the parts together with time)