You will need to print 12 pieces of whatever size you are printing.

Print Settings: I did include presliced files. Use these if you can. They are almost support free, only the connectors need support. To accomplish that, do this: enable supports. Enable on build plate only. Use a threshold angle of 10. I will attach a screenshot of those settings in my slicer. This model doesn't need a brim in my experience.

Assembly: You can watch this video: https://youtu.be/0gzQvTUp3mA They will print tight and won't move on their own. You need to loosen them up a little.