Bend an already bent geometry about different axis

Hello,

I am trying to tweak a geometry about both X and Y axes using the tweak volume bend command. The geometry is a thin volume. The first tweak about Y is pretty straightforward. When trying to bend again about X, the result I get is not what I want (though of course it is consistent with the command). So, first steps that are alright:

reset

brick x 20e3 y 10e3 z 1e3

move body 1 z 500

tweak vol 1 bend root 0 0 500 axis 0 1 0 direction 0 0 1 radius 10e3 angle 1

tweak vol 1 bend root 0 0 500 axis 0 -1 0 direction 0 0 1 radius 10e3 angle 1

Then I try:

tweak vol 1 bend root 0 0 500 axis 1 0 0 direction 0 0 -1 radius 5e3 angle 1

that tweaks half the volume, but its sides get stretched. I could use a root on the side and direction normal on the surface on that point and get a similar tweak that would stretch only the one side, and so on. I understand that direction should be normal to the surface so that the body is not stretched, but in a curved volume there are infinite normal vectors. To clarify what I would like, create this cylinder:

create cylinder height 21e3 radius 5e3

rotate vol 2 angle 90 about y

rotate vol 2 angle 180 about x

move body 2 z -5e3

tweak vol 2 bend root 0 0 0 axis 0 1 0 direction 0 0 1 radius 10500 angle 1

tweak vol 2 bend root 0 0 0 axis 0 -1 0 direction 0 0 1 radius 10500 angle 1

Notice that the tweaked volume touches the cylinder only @x=0. I would like the brick volume to be tweaked around the surface of the cylinder.

Could I somehow define a curve as a bending axis on the tweak-bend command? Could I vary the direction for each part of the volume? Any other commands I could use in order to bend the volume the way I want (plainly “downwards”) or create it by sweeping surfaces etc?

Thanks!

Would something like this work?

reset
create torus major radius 15500 minor 5000
create torus major radius 15500 minor 4000
section vol all yplane
section volume all zplane
webcut volume all with cylinder radius 15500
webcut volume all with cylinder radius 15500 axis z
del vol 1 2
sub 4 from 3
sweep surface 41 perp distance 5000
unite vol all