PC Case DB9 serial port and dual USB3 3.5" front panel adapter

I wanted to break out a 9 pin RS232 serial port from the header my PC's motherboard to the front panel, and at the same time retain two USB 3 ports.

This adapter fits in a standard 3.5" floppy drive bay. The USB3 cable is a StarTech.com USB3SPLATE removed from the PCI slot bracket. It's available from Amazon and probably other computer suppliers. I used an IDC ribbon cable and DB9 socket from my bits box.

I printed in ABS for heat stability, with the front face down on the printbed for a nice front finish. Designed in FreeCAD 1.0 - design files included.

The PC case is an old Cooler Master one which only has USB2 on the front panel.