Issue with BooleanDifference

Not sure if this is a mac issue or a more general one, but since I’m working on the mac at the moment, I’m posting it here…

I’m having trouble doing a boolean difference. The objects are in bad diff.3dm (505.7 KB). Trying to make a complex hole in a box.

The object for the hole was created by:

  • extruding a star-shaped curve for the main body
  • lofting that curve with larger/smaller circles for the end pieces
  • bool union on the above 3 objects
  • offsetsrf on the result to make a slightly larger object for the hole

I realize this is a relatively complex object to be using for a diff… that said, is there any way to tell exactly why it’s not working? I’ve noticed that several of the other manipulation commands don’t work either… wire cut and bool intersection, to name a couple.

FWIW, the object is the end of a shaft, which needs to insert into a matching hole on a handle. The slanted ends are to make it so that it can be 3d printed without supports. The star shape itself diffs just fine.


Hi Brian - as far as I can see the object in the box is incomplete- it has surfaces missing.


weird. it was complete earlier in the process. i’d seen one that looked like that, but deleted it and checked the one i was actually working with. will try again. thanks.

Here’s how I’d do this, if I understand the intent -

bad diff_OK.3dm (619.7 KB)


Looks like the problem was indeed in the surface - or more accurately, in OffsetSrf. It can’t handle the complex surface that I started with. Worked around it by going back to the original curves, offsetting, then lofting/extruding. I can provide a test file if it helps debug it.

If you see something that you feel should be fixed, then, yes, you should provide a file.