You have hex shapes ring shapes and spacers. These are just a few ways to assemble things. Later I will include an hour glass design using rings and one in other shapes. I created all of my designs with a free and extremely easy program called Design Spark Mechanical at this link http://www.rs-online.com/designspark/electronics/eng/page/mechanical It is similar to Solid Works but without the cost, only you time to learn witch only took me about 3 to 4 hours. Check out this short video and you will see for your self. Here is the link https://www.youtube.com/watch?v=ZXgMY3-hlgs