CAST IRON

 Have you ever wondered why vintage Singers are still sewing half a century or more since they were built?
I was at my local sewing center picking up some leather needles the other day and came across some cutaway modern sewing machine displays. The were made of cast aluminum, intelligently designed, and won't be sewing in 50 years. They aren't rigid enough, because they weren't designed for farm use in the 1880's, and they aren't made out cast iron.