IKEA Lack Cable transit 16mm (Table top penetration)

This is yet another cable transit through the top of a Lack table top or any other deck around 50mm thick. I've mounted my Anet A6 on a Lack enclosure and wanted to mount the PSU and Raspberry Pi externally to protect them from heat. I designed this to allow a USB lead and a couple of pairs of 12 Volt twin to pass through. There are two versions. The initial design had a 16mm internal bore but I found the back-nut became a bit scrappy looking due to the thickness of the threaded wall so I reduce