Why do I always end up with holes in mesh? (Yes, I'm a beginner)

Of course, I started only a few weeks ago and I enthusiastically push, pull, extrude, etc. I design for 3D printing, I use SolidInspector2, and I almost always seem to end up with difficult-to- or impossible-to-repair holes in mesh. Sometimes, deleting a face and reclosing it, removing some lines does it, but this time I’m stuck…

Here’s a seemingly simple model with holes in it that I cannot seem to close.

Q1: I tried redrawing many lines, which usually works, but none will accept to close the missing faces (in front and under the right leg). How can I manage to close them?

Q2: More importantly, what am I doing wrong that always gets me in trouble like that? I started that model from a tall rectangle obviously, extruded the T-shaped track from the bottom, then pushed the cathedral-roof and the oblique faces at the bottom both pushing from the face, and I did some quite severe cutting on the face that is currently exposed to get rid of an unflat surface. But… is there a specific order I should follow?

Q3: See included screen shot (png) with solid inspector on. I honestly never really understand the instructions when SolidInspector tells me to “fix the holes in the mesh.” What am I supposed to do with these red lines? Redraw them? Redraw the black ones? I’m clueless. :slight_smile:

I included both the skp model and a png:

example - holes in mesh.skp (1.1 MB)

I’m not sure what to tell you other than to keep practicing your basic construction skills, paying particular attention to inferencing feedback, making certain that every edge and shape you draw is on-axis, which apparently you are not doing.

The following picture shows your original object on the left with the coordinates of the four outside corners shown. The y values (2nd coordinate) should be the same for all four corners, and as you can see they are not, meaning–sorry–careless construction technique. I agree that it is basically unfixable. One could spend the rest of the day fiddling with the thing; much, much faster to construct it over correctly.

In the remainder of the picture I have shown a few steps to construct the object, which comes out square and solid with no problem. So, as I said, you’ve got to keep practicing basic construction, and really tune in on inferencing. You must see the expected colored dot and tooltip every single time you click the mouse, or it’s going to be a bad edge or rectangle or whatever.


The y values (2nd coordinate) should be the same for all four corners, and as you can see they are not, meaning–sorry–careless construction technique.

Don’t be sorry, I posted this example fully assuming my role as a potentially careless beginner :slight_smile: And thanks a lot, I had noted I sometimes got black lines that did not align, but your comments helped me realize the importance of paying more attention to the colored tooltips as a good start to constructing more carefully. Actually, the problem I was trying to fix with all the cutting was an originally non-flat face, most likely caused by inadvertently not aligning with the colored lines, I now realize. That takeway alone should get me a long way.

And now I also learned that, the moment I had a non-flat face, I should have just started over, especially for such a small model.

Thanks so much for taking the time. I’m hopeful I’ll experience less troubles from now on.

1 Like

You’re entirely welcome. Thank you for making such a good effort to provide us with sufficient information to help you and for not letting your ego get in the way of accepting the advice given.

Ask us as many questions as you wish, and we will be delighted to help again if we can. (I use the pronoun “we” not in the royal or editorial sense, but because there are many talented people here who are always eager to help.)