Warren, as we all know, in the mind of a politician there are three types of undesirables; those who own firearms, those who can think for themselves and know how to make things, and worst of all, owners of 3D printers! Not only can they print out weapons of mass destruction, but also the multi-engine bombers to carry them! What a pack of paranoid plonkers!
I use 3D printed PLA patterns to investment cast aluminium radiator parts for my Lewis repros. Very handy gizmos!