Model Rocket Centering Rings

In the past year i've been getting into building rockets via kits. I've started to build my own and decided to start printing my parts for convenience and to save Money. I've been able to find Centering Rings here and there as parts of other kits but the results were always iffy. I decided to make my own centering rings. I've made rings for 18mm (Estes A,B,C) and 24mm (Estes D,E) motors. Some straight rings, some with a notch for a metal retainer clip. The size tubes i've included rings for vary from BT-80, BT-70, BT-60, BT-55, 29mm and BT-50. I made the centering rings 2mm larger than the 18/24mm tubes respectively, so these are designed for a snug fit. I've been easily filing the inner rings just a bit when i need a bit more space, or when trying to fit them on a motor tube that might not have a perfect end to prevent it from crumpling. I've also included the ring to slide inside the motor tube itself as a stop for your motors. (These are labeled 18mm-EngineMount-Stop and 24mm-EngineMount-Stop) Files with "RetainerKey" at the end of the filename are the centering rings with a notch cut out for your metal retainer clips. Hope this one stop shop helps you in your rocket building endeavors.