Recently we had a request to make circular and helical small diameter bends for a lighting project. We designed special heaters for the project and made our prototypes with clear, transparent CAB (butyrate). The trick is proper annealing. We not only heat our bends to approximately half of their melt temperature for a specified time, but we also control the cooldown. This allows the resin to relax and to reduce stresses that would either cause the bend to tighten or unwind.
Thanks to the butyrate prototypes we will soon offer these bends in a colored stratus blend.