Lister, have you ever been hit over the head with a welding mallet?

The rear panels have hanger flanges which allow them to hang on the roof panel flange while they are aligned and screwed in place

Measure from the base casting lower flange and lift the casting four inches (4 or 100mm) off the ground by adjusting the four corner leveling screws to the same height.

let's say the welding failed, and this thing goes boom and out shoot the control rods, that's there to keep them from doing bad things like punching a hole in the top.

It was a place where we were growing algae and welding plastic and building tools and making a lot of mistakes, or, as Edison said, we were finding the 10,000 ways that the system wouldn't work.