The welder has completed the first stage of the battery box fabrication.

This consisted of:

Cutting out the bottom of the car.

Fabricating a structure to support the batteries and motors.

Welding that structure into the car to replace the strength of the missing floor and stiffen the car.

These views show how the thin metal of the original bottom is welded to the beefier battery box wherever possible

The roll cage needed to be tied into the battery box to help stiffen the car and protect the driver.

The original cut weakened the battery box

By adding metal, the strength was added back in.

And the roll cage is firmly anchored to the floor.