





parameters
>floor height (variable)
-2800mm<4000mm
>rise height
-rise height=floor height/20
>tread width
-tread width=470mm
functions
>step height
-translate(step n)= n*'step height'
-rotate(step n)= n*15deg
>double helix
-height= 'floor height'
-pitch=6/5*'floor height'
>handrail
-draft/angle= atan ('rise height'/ 'tread depth')