[jjav]

> I can work with metal. I can't work with plastic.

You're right that metal (and wood) are much more amenable to work with in a home workshop.

However:

> 3D printing options aside

I wouldn't put 3d printing aside. The main limitation is the size of what you can print, but if the part is small enough (depending what printers you have access to), it is a game changer. We don't have a 3d printer but my child has access to them at school and watching him fix all kinds of gadgets by 3d printing replacement parts has been very cool.

[mythhabit]

If you have the tools to work with metal, you can use those tools with few, if any, modifications and do the same thing with nylon.

[CraigJPerry]

Even for larger items I’ve often found printing sub-assemblies and gluing together to be a useful technique.

E.g. I needed to replace a shaped plastic cover for a handle mechanism on a motorhome/RV. Breaking the design into two parts and making it so they clip together (rather than permanently gluing in that particular case) meant I could print a complex design without supports.