I messed up and called the tension hoop in a previous picture the “bracket band” Sorry.
So what’s a bracket band? Brackets, or “bracket shoes” are the lugs that protrude out from the rim to anchor the hook-and nut so that you can tighten the head.
In the simplest banjo construction, they are bolted on to the outside of the rim by holes drilled through the rim - the bolt heads are on the inside.
The bracket band eliminates the need to drill through the rim by attaching the brackets to a ring that fits onto the outside of the rim, not unlike the hoops on a barrel - it adds mass, and stabilizes the rim - does a lot of things.
Obviously, resonator flanges perform the same function.
I have a few ideas about how to do this in another way, which I will post tomorrow, if I can get it together.
So, you cut strips of brass with a bandsaw, and sand the edges with a disc sander. Then you roll them into circles - you can see on the bottom picture how wonky the rim roller is - it makes a spiral or helix. You have to bend it straight
A lot of steps here, so, more soon.