1. Version : NX11.0.2
2. Operation : Planar Mill
3. Request : Automatic creation of engage tool path.
I did not set it on Engage. However, the engage tool path is created automatically.
What is the cause and how do I avoid being automatically generated?
It might be that an extension is automatically added to your path to satisfy the Minimum Clearance around the part. in the NCM dialog, Engage tab / Open Area group check the setting for Minimum Clearance. you can turn it to None and see if it help. If so - you may also want to leave it extended for the engage, but turn it off for the retract.
All engage settings are none. The minimum clearance is also none.
But the results do not change.
This appears in the zigzag pattern process on the plane.
I'm investigating this case with the part file you uploaded. Currently I have no explanation for this other than to say that it seems like a legitimate bug that needs to be fixed. At one point I had the behavior you desired after trying different inputs and generating the tool path over and over, but then I couldn't recreate the possible solution after closing and opening the part file again.
The one workaround you currently have is to use the Tool Path Editor to delete the unwanted engage segment and then turn the resulting segment that was formerly attached to the deleted engage into a traversal motion. This isn't ideal, but you get the tool path you need.
I will continue to investigate this by asking the developers for their explaination and see if we can get a fix. This may need a PR, so as long as I have your permission to use this part file for that then we should be good to go.
I made a look on that part and i see that the minimum clearence is set to 50% of the tool. If you set it to 0 than it works as desired. The problem for you is that the dialog box for minimum distance is not available when the engage is set to none.
Open the "Non Cutting Moves" - switch the Open area - Engage Type to Linear
Set the Minimum Clearence to 0
Than close the menu and generate the path.
Open the menu again and switch back from Linear to Same as closed Area.
Now the min dist is internal set to 0.
Regenerate the path again and the tool path looks like you want.
In general if you switch the stepover from Variable passes to Constant than NX generates a path without lifts. This is also the case if the Cut Angle is changed from 0 to 4 degree.
I insert also a part with a correct toolpath