Unusual Group Behavior

I am trying to make a group in an object that has been edited extensively. After selecting multiple lines and selecting group from the drop down list, a frame appears around the group. If I click outside the group, the group frame disappears - as it should.

The problem is if I try to select a group, I go back to selecting lines. The only time the group frame appears is when I select the area that the group is located. If I select a group, it doesn’t behave like a group when I try to use it with the curvy loft extension.

On the other hand, groups behave normally if I draw a simple triangle and make it a group. I am assuming there is something different with my model that isn’t “group-able”

Any help would appreciated!

I can’t follow your description. Perhaps you could share the SKP file?

Are you using layers?
Have you tried selecting your group from the outliner?


Here is a link to the SKP file


I am not knowingly using layers.

I tried selecting groups using the outliner and that worked perfectly!

What is the purpose of outliner, and why am I unable to select groups outside of outliner?

Your Groups are just a small collection of edges stacked on top of each other. Unless you only wanted a few edges as a Group, the Groups you have were not made correctly.

Try double-clicking on the face to select everything attached to face, then make the group.

The group’s bounding box and it’s entities are highlighted in the selection color (Styles panel > Modeling Settings tab, “Selected” color swatch.)

See Cat’s comments above, … If the group only contains one edge, and it is orthogonal and lying flat, it’s bounding box will be as long as the edge, but have no other thickness in the other two axis.

So when it is selected, it will look like only an edge is selected.

If you created a group with only 1 GuidePoint, it’s bounding box would have no length, height or width.

Wow, thank you all that replied.

I am now able to make, select and use groups.

The purpose of using a few edges in a group is to allow curvy loft to match the number of segments between two airfoil sections. This can be troublesome if the airfoil sections are different sizes (tapered wing panel) and/or not aligned with each other (washout or sweep).

When the left and right airfoil have the same amount of line segments, it is possible to generate g-code to run my cnc hot-wire foam cutter. Matching line segments allows the foam cutter to keep the correct timing when the wing is cut out.

You may be interested in trying out BezierSpline to adjust curve segmentation. You will need to sign up for a free membership to download.

Also this old thread on using public domain tables to create airfoils may be of interest.