The relationship between the left and right sloping surfaces is carved out.
This allows you to choose how the top plate loosens by twisting it.

Joseph Naomi Yokota

As of today, the back weighs 2778.6g.

This photo was taken at 20:02 last night.
I was using a hot pin to prepare for carving the central groove in the back plate.

Joseph Naomi Yokota

Work resumed the other day.