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This whistle fights fascists | How thousands of 3D-printed whistles are derailing ICE.
(www.theverge.com)
This is a most excellent place for technology news and articles.
Not saying anyone's doing this for whistles in particular, but you can make PET filament from salvaged bottles. And VHS tape, but I really doubt anyone is going to be able to print something that needs to be as precise as a whistle from VHS tape. From what I've seen it comes out... lumpy.