After changing the oil in the gearbox for the first time, I decided that I was not going to tolerate the resulting mess again. Oil everywhere. It was difficult to control the oil spurting out of the original plug. A small spigot was added, no more spilled oil!
A dial indicator with magnetic back attached totally eliminates any backlash when moving the cutter in and back. A small, strong magnet is attached to the carriage to provide a fixed reference for the indicator stem.