Doing a Cut through multiple bodies

[RogerInHawaii]

When you have a sketch and use an Extrude operation to do a Cut, the Cut occurs through ALL BODIES in the path that are currently visible. Right?
I'm pretty sure I've done that dozens of times in the past. In fact I had to make sure that I had certain bodies NOT VISIBLE in the path so they wouldn't inadvertently get cut when I didn't want them to.

But today I was doing just such a cut, with two visible bodies in the path of the extrusion, but it only cut ONE of the bodies. I tried a bunch of variations, making sure I had the Active Component set high enough in the Browser hierarchy so that it incorporated both bodies, but it still only cut through one of them.

I finally had to resort to doing the extrusion as one to create a new BODY and then doing a Combine operation, using that Body to Cut, individually, the two other bodies that I wanted to Cut (and then getting rid of that Body Tool).

But, man, I swear I never had to do that in the past, that all I had to do was Cut type Extrude in order to extrude all the visible bodies in the extrusion path. Or am I just going crazy. 🙂

[jeff_strater]

I just did a simple test, to make sure we had not broken anything fundamental.  It worked OK in that simple test, so we'd need to see your design and a screencast showing what you are doing in order to see what is going on.  Is it at all possible that one of the bodies was in an external component?  That is the one case that I know of where cut across multiple bodies will fail to cut (external components are read-only)

[laughingcreek]

There are circumstances where extrude will remember ( or seemingly just decide, or use some kind of alchemy) that a particular body isn't suppose to get cut by the extrude.  one example: turn off body 1, extrude cut body 2, turn on body 1, go back and edit your extrude cut feature.  In this case the extrude cut remembers not to cut body 1, even though it is  now visible.   There are other scenarios.

To over ride this behavior, look at the last line of the extrude dialog box.  it says "objects to cut".  open it and select the bodies you would like the extrude to cut.

[RogerInHawaii]

No, it definitely was not an external component. I've never used that capability in any of my models.

The model that I did it on is incredibly large and complex. Each operation takes a long time to complete, so I'm not inclined to try to go back and reproduce it on that model and record the operations, since it would crate a HUGE video file.

In the original situation the two bodies that were involved occupy, partly, the same 3D space and have one of each of their faces coincident and it was on that coincident face that I created the sketch that I then tried to Extrude/Cut through both bodies. So I tried recreating that in a simple model. But this time it worked, it did indeed cut through both bodies.

So, I'm baffled.

I was able to get around it by doing an Extrude/New Body through the two other bodies and then using that new body to do a Combine/Cut. So I can indeed proceed with my project, but it was just a weirdness that still baffles me.