I have to give my thanks to Deborah Read for posting this bangle pattern roller on her blog! I quickly ordered one from Otto Frei and got it a few days ago. It's a beauty with seven different patterns. Here's a photo:
I tried different gauges of copper wire and even tubing I had on hand and love the results! I'm not sure I tried all the patterns yet. The photo below shows what I've made so far. The wire on the right is 12 gauge ... I think I'll use it for earrings.