Visor Knob

I used to find something like a screw and a screw cap that I can glue on my cosplay helmet to hold my visor. I cut the threaded part (bottle neck?) of 2 soda bottles of 2L: large enought to give me a good surface for glue adherence, strenght enought to hold the visor, the cap is totally screwed in what? 2 turns? Do a great job but look very...cheap! So I decided to print these visor knobs and then...it look amazing!