Summary

Speaker grill , using scad make any size speaker grill .

Make ring, print
Make grill , print
super glue grill to ring then attach to 4 holes on the speaker .

As a aside I use PETG to print and I used this on 2 speaker boxes pairs that I made . They work great and the one speakers get kicked around a lot and the grill is hanging in there . It falls on it's face a lot and no problems with cracks yet . I really am surprised as how durable this is for such a simple idea . Grills even from China are not cheap and getting the right size is always a problem for the speakers your buying and doing it this way I don't really have to worry about that problem anymore . I buy the speakers, create the box , mount the speaker , take measurements of the hole and print it . Simple .