Can't create closed item on face

I am trying to create a connector cutout in a model face and it is driving me crazy. I tried Edge Tools by ThomThom and it doesn’t seem to find any gaps. I added a few lines across the space and some sections are closed and can be selected individually but other can’t. I have searched and tried numerous things and am baffled. Model is attached. It is from Thingaverse 43049 but made taller for extra things in the top. Once I get the first one I want to copy it to another location and it seems like I should copy it before I punch the hole as I want some on the opposite side. But the immediate problem is closing the item. (tallboxroundedcorners2.skp (155.8 KB)

There is some kind of a tiny error (maybe they are ever so slightly non-coplanar) with the arcs on the left. I erased all the extra lines and guides and the arches, and redrew them with the 3-point arc tool.


It will intersect and seemingly form faces etc, but some parts are very very slightly non-planar.
So another issue is that it’s very small - or at least it has some tiny geoemtry.
SketchUp’s tolerance is 1/1000".
Two points closer than that are assumed to be coincident and so if the two ends of a very short edge are so close it’s not then created, then the face that relies on that edge is not made and so on…
Some of your rounded shapes have very short segment lengths.
Those might then cause issues with FollowMe, PushPull, Intersect etc which will interact with them.
Tiny geometry can exist, but it can’t be created.

Make your object into a component.
Add a second copy off to the side.
Scale that up x100.
Do your editing in the giant copy, because its geometry is so much larger the issues with tiny edges etc won’t recur.
The changes you make in there will be reflected in the proper-sized smaller version.
When you are done delete the now-unneeded giant version.
The tiny geometry inside the component exists just fine, it’s just the making of it that is awkward…

As has been said, the edges/faces are not coplanar.
I find the entire side is a bit wracked out of square as well


Ok. I see now that the model faces are not exactly aligned with the axes. I had previously enabled showing axes by color and the lines on the faces showed up colored which is supposed to show they are on the axes. But that apparently doesn’t show small errors (so what good is it really?). Is there a reasonably easy way to align the faces with the axes or am I better off to start over? I was hoping to save some time and effort by stating with a box with the beagle bone connector openings and expand it with room for more circuitry but the original model has a few issues and I think I may have made them worse when I pulled the height of the walls higher, etc. How do I avoid getting the geometry slightly off when manipulating things? Was some of the problem that the dimensions are odd units (many decimal places) and when manipulated the final destination doesn’t have that much precision?

Edge Color by Axis is indeed coarse and quite useless as a means of verifying absolute accuracy.

As shown, the Text Tool displays endpoint coordinates by default.
Text tool is useful but rather slow and cumbersome for this, plus there’s the clutter of text it creates.

Query Tool is what we need here. With this you can quickly interrogate the model.
Utilities Tools includes the Query Tool — Extension Warehouse

Attempting to fix a wonky model will in some ways help you learn about manipulating geometry.
You’ll also learn to judge when it’s best to scrap it and start over.
It’s a simple object one can model accurately in a few minutes, why waste more of your time?

• Model the box with square corners from which to easily pull guides for hole layout. The radiused corners last.
• Turn off length snapping
• Set precision to 0.000 or more
• Make a habit of always using inference locking and keyboard entry of dimensions.
Don’t click and hope. Tell SU exactly what you want with inference locking and keyboard entry.


Very helpful tips I will work on!I have entered some dimensions with the keyboard so I think I have a good start on that. Need to investigate the “inference locking” thing. Think I will go back to the original model which only has a few issues (that I know how to fix) and go from there.



Inference Locking

Inference Locking Example

I have a similar problem and wondering if anyone could help.
I’m trying to fill the faces of the triangle on this.
It would only allow me to select the faces on the bottom plane, and none of the slanted faces.
I checked and it seems all the edges are connected without any “gaps”.
So I’m not sure what it could be.

Thank you in advance… If someone could help that would be really appreciated!

Triangle first draft 3D.skp (120.4 KB)

The ridge and eaves of most of the roof planes are not drawn exactly parallel.
So then can never for a single roof plane using them.

If you add a diagonal across then two triangles will form, but they won’t be exactly coplanar.
The diagonal cannot be erased without losing the faces.
You could hide or smooth it.

However, it’d be better, and easier in the long run to redraw it properly.
Use the vary inferences and tips, to ensure that your new lines are parallel with the axes [RGB] or other existing geometry [Magenta].
If you change your Style to display edges by axes you will see some edges in red, and a lone edge almost along the red-axis that is black - it should be red and parallel with its cousins: if you zoom in close with View > Axes ON, then you can see that it’s not drawn along the axis, it’s slightly crooked - enough to stop a single roof plane forming…