Ok I have the main body built 9x18x36, but for the life of me I can't figure out the swinging bobs on the doorway. everything i've tried hasn't worked. there all to loose and have to much side to side movement. So I turn to ya'll for ideas.

I used to use the wire for holding up false ceilings but any will work if it's stiff enough. Bend a piece in a "U" shape that will reach from the top to the bottom stop. Attach a piece of wood at the top and use wire staples at each bend of the "U". That way they wires cannot move back and forth and you can cut them so they just cath the stop down in the bottom of the trap. As a suggestion, I would make the "U" wires about 1" across. If you are trying to catch "tame" birds, use about any wire mesh. If you are after "feral" birds use at least 1' square wire mesh. Good luck.