Boolean cut between shapes does not produce expected result

[dstraub-pf]

Hi! I am trying to cut a cylindrical hole into a toroidal shell. The function I'm using works "most of the time", but for same orientations & parameter values does not execute the cut correctly. Here is a minimal reproducible example.

import cadquery as cq
import cadquery.occ_impl.shapes as cq_shapes
import numpy as np

R = 3.3
r = 2.2
t = 0.05

# torus-like shape
inner_tor = cq_shapes.torus(d1=R * 2, d2=r * 2)
outer_tor = cq_shapes.torus(d1=R * 2, d2=(r + t) * 2)
torus_shape = cq_shapes.solid(outer_tor.Faces(), inner=inner_tor.Faces())

#cylinder
xyz1 = np.array([-0.5, -2.4 ,  2.1])
xyz2 = np.array([-2.6, -1.0, -0.1])
length = 5.0
radius = 0.1
plane = cq.Plane(origin=tuple(xyz2), normal=tuple(xyz1 - xyz2))
workplane = cq.Workplane(plane).circle(radius).extrude(length)
cylinder_shape = workplane.solids().val()

cut_shape = torus_shape.cut(cylinder_shape)

The result is as expected, getting a nice hole in the torus shell:

The intersection looks like this:

Now, if we change xyz2 from np.array([-2.6, -1.0, -0.1]) to np.array([-2.7, -1.0, -0.1]), it suddenly doesn't work anymore: this is the result of the cut operation

And this is the intersection:

I suspect this is an OCC issue, but I am running this in an automated script and don't have the liberty of manipulating coordinates by trial and error. Any idea of a workaround would be greatly appreciated, thanks!

[adam-urbanczyk]

I can reproduce the issue with 7.8. I'm afraid that a workaround will be to not use the bool op in one shot. I.e. do something like this

from cadquery.vis import show
from cadquery.func import loft, solid, split

w = workplane.val()

oface, of2 = split(outer_tor.faces(), w).faces()
iface, if2 = split(inner_tor.faces(), w).faces()

side= loft(of2.edges(), if2.edges())

show(solid(oface, iface, side))