Here are a couple quick photos to illustrate how the zippers work on the DangerBird.
A zipper half is stitched to the hammock, net, and overcover.
The zipper is simply put together sharing the zipper half stitched to the hammock.
Carefull planning of the zipper halves is very important. There is a right and wrong way! Before stitching anything, check and double check that the two halves will zip together properly. It's pretty easy to tell if you've got them backwards. See the following photos.
Zipper halves correct.
Zipper halves incorrect.