I designed an easy tap handle to hold the Empire and Rebellion Coasters by IVIUPPET https://www.thingiverse.com/thing:819128
Print with the back on the build plate with minimal supports.
Threaded portion is 3/8-16(standard US tap threading). I can add a version to allow the brass inserts to be used if anyone would like.
The coasters fit snug, just add a little super glue to make sure they stay in place.