Snapmaker U1 cover modification.

While using the U1, I decided to modify the case frame I previously posted here and add a USB port. The cable to the rear USB port runs through a small (4mm) channel in the side base. The USB cable should be 1m long. It's convenient to use a USB plug with a side right cable exit. The cable outlet in the PVC rear panel simply needs to be cut to fit the cable. The USB port is located on the front of the case.