slicing1.py

import DraftGeomUtils
import Draft
from FreeCAD import Vector,Base
import math


def findOutsideWire(wires):
    biggest = wires[0]
    for i in wires:
        if i.BoundBox.DiagonalLength >= biggest.BoundBox.DiagonalLength:
            biggest = i
    return i

sel=Gui.Selection.getSelection()
obj = sel[0]
bb = obj.Shape.BoundBox

cutterdia = 1.25
offset = cutterdia/2.0
stepdown = 1
zbelow_bottom= -1

ztop = bb.ZMax
height = bb.ZMax-bb.ZMin

numsteps = int(math.fabs(height/stepdown))
wires=list()
slicelist=[]
z = height-stepdown
for n in range(0,numsteps-1):
    outside = findOutsideWire(obj.Shape.slice(Base.Vector(0,0,1),z))
    outerPath = outside.makeOffset(offset)
    slicelist.append(outerPath)
    z= z-stepdown

lastpass = findOutsideWire(obj.Shape.slice(Base.Vector(0,0,1),bb.ZMin+.0001)).makeOffset(offset)
slicelist.append(lastpass)

comp=Part.Compound(slicelist)
Part.show(comp)