Laptop Optical Drive Stack

I have recently begun making copies of my own movies to ensure that the data does get lost when my discs eventually have faults I created this stack to hold as many drives as possible I have attached a usb hub to the side which has allowed me to have multiple devices plugged into my pc. The print was joined with M3x5x4mm Heatset Inserts x27 and M3x8mm socket head screws x27. this system is capable of fitting all thickness of laptop optical drives though was designed for 12.7mm laptop optical dri