Reversing a Union command

HI, I have been designing a 3D piece and needed to bevel the edges of a join so that I could get extra strength.

I then prototyped a 3D printed model but now want to go back to undo the bevels and separate all the elements so that I can make some adjustments to the design.

How do I undo Union commands?

You can’t separate united parts like that. However you can delete parts of a body, by selecting a set of faces and then oressing the delete button.

Thank you. So to try to tweak a design, I should only delete those aspects I want to re-create?

If I choose a face that has adjoins another and along the adjoining edge I have used a filet or chamfer, will it delete those as well, or will that prevent the face being separated and deleted?


When you delete a set of faces, shaper will do the following:

  • remove the faces
  • find the holes in the body
  • try to extend the faces at their open edges to create a closed body

If that’s not possible, delete will fail. Otherwise delete will extend your faces to create a watertight body.


Istvan offers good advice but I have found that in situations where your model may be a bit complex to:

  1. Make a copy of your workspace and try doing what you expect to work; if yes, great; if not

  2. Make a new workspace and create the simplest solid that matches your model. See if your technique works here. If yes, your original model has some other complexity that you need to sort out. If not, you are unclear on some concept and may have to research or ask for help.

Another way is simply to start over. You will be more attentive to what you are really doing. Also repeating something usually takes much less time than the first time.

Hope this helps…


To add to this
Before doing an Union’s
We normal make a new Group and Duplicate the pieces to be joined into it
This way there is always a copy of the individual parts
And as far as a feature request! :blush:
It would be nice to have a “Duplicate Group” function directly from the Group Tab
Or at least if you highlight a Group in the Tab when you go to the Transform/Copy tool the new parts would be written to the highlighted Group as opposed to the current working Group or for some reason the very bottom Group!