By the way Mr Musk,

 

When the compressed Earth, with enough mixture of

construction aggregate isn't strong enough,

the giant CNC machine may crack the the cube itself,

and that may not be so desirable. Although this

depends on the overall experiment.

 

Here is a way to counter this.

 

First from an aluminum or whichever metal cube,

cut away into making a frame. Which I would say,

4 sides of a rectangle to the sides = bars.

and the bottom surface is holding them, but it

has many holes.

 

This way, the earthen walls can be slid into the bars

separately, once the bottom surface is placed on the

earthen flooring. Which means, the use of construction

aggregate can be far less dense, and one needs to

worry about cracking far less, or there won't be any cracks

due to the CNC machines. (As it will only use compression)

 

So that is another way to counter it. Of course,

the left over metal subtracted by the CNC will always

be re-used so there is no waste of material.

And the bars can be created in such a way that it

has holes to the sides, allowing another bar to slid

into once the walls are placed, then filled up with cement.

 

It is still record time, and also the material usage,

of course is about the same. As the metal bars and surface,

is just there to be used as a frame, it can be fairly thin.

For low rises.