CAD model of a number 2 Camalot caming device from Black Diamond used in rock climbing.

Also see my number 1 cam model from BD.
When I 3D print these I print the lobes, the three pieces of the stem(will combine these into one .STL and the trigger(might not do this the triggger wont go on oops!!). The other pieces are found at the hardware store, in particular lowes hardware section has hollow aluminum rod which I use for axles, couple screws to go in there and A brake cable from pretty much any bicycle(you only need a very short piece with the lead/zinc piece. If you ask nice at your local bike shop they will probably give you one)

not suggested for climbing