Machine Simulation Preferred Direction of Rotation

[Benjamin-Schaefer]

Much appreciated fusion community,
I am currently sitting on an issue with the machine simulation. It's about preferred directions when swiveling the rotary axes. We are working on a DMU75 MonoBlock. The special thing here is that the axes of the A- and C-axis do not intersect, but have an offset of 70mm. The A axis, however, can swivel ±120°. Depending on the machining situation, it can therefore make sense to swivel in one direction or the other. For example, with very long or short tools in order not to exceed the axis limits.

What options do I have here to achieve this?

You can set a preference for the axes in the machine definition. However, the simulation will stick to it even if there is a collision or the axis limits are exceeded. I have not yet understood how the simulation behaves with no preference. In any case, the simulation does not try to avoid collisions or axis limits.

[a.laasW8M6T]

You may have no preference set in the machine definition, but this can be overridden by the post properties in some cases, make sure its set correctly there too:

Additionally when a toolpath is created,  it is unaware of the machine configuration, so will not necessarily force an output of a particular orientation.

In tool orientation for a toolpath you can in some cases influence the direction by setting the X axis appropriately.

[Benjamin-Schaefer]

Thank you for the detailed feedback. Especially the hint on the selection of the X-axis I will have a closer look.
We are using the customized generic Siemens 840d post from Autodesk. There is no switch for preferred tilt direction there in the standard. However, the post seems to take over the setting from the machine model. When I change the setting, the output also changes accordingly.