Recently our webcam came apart. The focusing cap came off the front of lens area. It still has to be able to spin, so it was essential to place the glue carefully on the inner lip, not inside the spinning part to avoid spoiling the mechanism. The fine nozzle on Best Glue Ever helps tremendously.
I placed a tiny line of glue spots on both surfaces, and let them sit for while until the spots had turned clear and super tacky. Then when I joined the two surfaces, they grabbed and held, but the cap still spins as before.
Magically Perfect Tip:
When adhering two non-porous surfaces, like plastic, sparingly place Best Glue Ever on both surfaces, and let it cure to clear and tacky before joining them. Just like a contact adhesive, without the strong chemicals or odors.