Parametric cosine Christmas bulbs

thingiverse

Just a joke - reminder about my school days when I drew such cosine curves in polar coordinates with pencil and compass. Update: I added a script to make a bulb over generic rhodonea curve. This is controlled by the ratio of N and D variables, giving the same results as the two earlier scripts with specific values. The related formulae and pattern samples can be found on Wikipedia's Rose (mathematics) page. Update 12/27: I added a twist parameter to get twisted objects - compare rose2 against rose_gen. I set a 1mm wall thickness because my old printer has a 0.8mm nozzle. Now, I've tested that 0.5mm thickness is okay for a 0.4mm nozzle. So, I recommend regenerating STL files with a thickness matching your printer.