A step stool that locks into place when in use, and folds away for storage.
Locked open
Closed
Closed, interior
Function side view
Stationary part
Stationary, side
Stationary, inside
Stationary, top
Moving part
Moving, side
Moving, top
Build, open
Build, closed.
This is from an earlier design, note it doesn't close completely
The plans include some adjustments not present in the constructed version.