Here are photos from the resin spine stress test

Using two mini miter cutters from Harbor Freight Tools, I cut the brass tube main runners. The one on the right is doing the cutting, the one one the left is an old one, and simply holds the other end. The cutters are good for brass, but not good for cutting steel rod.

The runners are done in brass, with steel rod inserts.

The test spine is hung from my closet dowel

A 10 pound dumb bell is added

Another 10

Another 15 for a total of 35