Help and Feedback on my model

Following the questions that I had this morning, I just wonder if someone could have a quick look at my model and give me feedback, and help with a couple of questions.

Clip 2.skp (1.1 MB)

When i finished the model, the bottom surface was covered in lots of little spots, which i deleted… But there are 2 things I can’t understand.

  1. The line on the bottom… when i deliete it, the entire face vanishes

  2. Why is the strip front/back of the hole dark? I assume that this has something to do with the way that I created the initial model… But how do I fix it?

I look forwards to any thoughts you have.


All your questions are related.
This specific model is too small, the line you want to delete needs to be smoothed and should appear on the other side but it is bending because of the scale of the model.
Try following up the questions you have already asked and listen to the answers.

Sorry… I didn’t see the connection with this issue and my questions about Push/Pull… I thought they were totally unrelated.

I only posted this as someone suggested that I show my model…

I hardly thought this was that small… its over 1" long… And there are no curves, its all straight lines… So I just wanted an understanding of what I did wrong and why that line is there and can’t be deleted.

And more importantly, what the dark grey area shows around the hole and how to fix it. If I understand this correctly, the dark area is an inside face… And using CADSpan’s preview, I can see that the outer face is actually on the inside.

So somehow I have managed to invert this face and have no idea how I would go about fixing it.

It doesn’t really matter… I 3DPrinted it and it came out fine… So I am not particularly worried… Just trying to learn really.


Edit: Hang on… Fixed it… Right click and there is a “reverse face” option… Clicked that and now it looks right.

So all I need to understand now is why I have a line through the middle of the bottom (flat) face which removes the face when I delete it… I have drawn it back in with the line tool and after clicking 2 corners, the entire face re-appears, so perhaps thats all there is too it.

That is a bit strange. I deleted the extra line, and the face disappeared, as you said. Then, without doing anything else, I traced over one of the remaining lines and the entire face appeared, sans extra lines and looking perfectly intact. Go figure.

As for face orientation, it’s simply a best practice and a habit you should get into to get all the faces pointing the right way. Personally, at this point, I would be embarrassed for someone to see a face back I had inadvertently overlooked. And it really does make a difference to a lot of 3D printing apps, not to mention third-party renderers.

There are quite a number of face orientation extensions, including one called FrontFace, available from the SketchUcation Plugin Library. Also, I have the Reverse Faces command available on a hot key so I can quickly take care of reversed faces as I work.


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The problem is the two faces that you wish to make one are not quite coplanar.
The same holds true for the face surrounding the hole.
That is, the edges of the hole are not perfectly coplanar with the four corners of the surrounding face.
I also find one of the edges of the face surrounding the hole, is broken into four segments.

While these discrepancies are minuscule, they’re enough to cause problems.
In the attached copy of your model I’ve grouped the geometry, flipped it over and moved it such that one corner of the bottommost face is at the Origin 0,0,0
That makes it easier to compare the position of vertices by labeling them with the Text Tool, whose default text displays the coordinates of an endpoint.

You’ll find the Query Tool makes investigation easier.

The key to precision modeling is Inference Locking and Keyboard Entry of all dimensions.

Clip 2 - Fixed.skp (71.8 KB)