Okay, the 3D preview in a 3rd party tool seems fine:
Using the new beta of Carbide Create:
we have this as a very small part if mm are used for the import…
Setting things up to match the small metric size we get:
and we draw in geometry for the import:
and set it to 1:1 scaling for XY and for Z:
which seems to match (though the top is red which indicates it’s coming in at slightly more than 1mm — we edit the Job Setup:
and the model loses the red tint.
We then right-click and choose “Create outline vectors”
OK
and offset by the radius of the tool which will be used:
and then do a 3D roughing toolpath:
and then a 3D finishing toolpath, adjusting the stepover:
which has a pretty good preview:
I suspect for parts such as this you actually want MeshCAM: