Trying to make the clear pen holder. I need a template to drill the holes, which will be 120. The material is 3/16 acrylic. Drill acrylic can be difficult if you don’t use the correct bits. I’m think I should have for sections twice. I’m thinking the center spine should be slotted to interlock the two center spines. Talking to my acrylic supplier I should just be able to glue the center spine and other components without any bracing since there is little weight. Each section is 30 pen holes. The holes will be 7/16", but has to have spacing to keep from chipping. I’m not sure on how to start the octagon. As a starting point I’m thinking 9" across on the points.