What is a create contraption?
Basically, a create contraption is a structure built using the mechanical aspects of the Create mod in Minecraft. I use Create, as well as several add-ons, including; Bits N' Bobs, Aeronautics, and Power Grid. Of course there's more, but those are the bigger ones.
(Kind of a sidebar, but the modpack I play currently has over 90 mods, a lot of which are either tech or worldgen related. Biomes, structures, etc.)