Hi. I have made a 3D model of a base for an UDOO single-board-computer. I looked up the process for converting the model to a file ready for 3D printing and installed Solid Inspector2. It gives me errors for correction - Surface Borders and Internal Facing Edges. I cannot seem to get them fixed. I have tried redrawing on the same lines and shapes but more often than not, it does not work.
Any help would be appreciated.
For starters, you need to understand what those flaws mean. You have to fix the model, not simply redraw the same geometry.
Surface borders are (sets of) edges that have only one adjacent face. They expose the fact that a face in SketchUp is actually infinitesimally thin and physically unrealizable. They also usually create holes by which the exterior and interior of the tentative solid are connected to each other, again making it physically unrealizable. To correct surface borders, you have to either close up the hole by drawing a face over it (which can imply using a lot more printing material) or add to the model so that the area where the border was comes to have thickness and enclose space connected to the rest of the interior. There are lots of alternative ways you could do these things, which is why Solid Inspector 2 can’t repair them automatically.
Internal faces are “flaps” that project into the interior of the object. Since they are “inside” the supposedly solid volume of the object, a 3D printer doesn’t know what to do with them. You can use section planes to reveal them and then you can edit away internal faces.
UdooBaseWorking6.skp (1.2 MB)
@slbaumgartner: Here is the file I made. I could not find the upload button before.
To start, I made a rectangle of specific dimensions. The rectangle was raised 10mm using the Push/Pull tool. To make sure I had a border of material that would extend past the edge of the SBC, I added 5mm x 5mm squares at each corner. These were also reference points which were used to draw lines so could exactly place the holes to drop down through the base.
The base is 10 mm thick. On the top side, I placed circles of one size and used the Push/Pull tool to drop the hole down 5mm. On the underside, I made circles larger and used the Push/Pull tool to make holes 5 mm up into the base. All unnecessary squares and lines were deleted. I then made rectangles around the holes where I wanted the feet of the base to be. I then used the Push/Pull tool to raise the base up 5mm.
Given all that, I am not sure how to go about correcting the problems. I looked on the forums for ways to correct the problems and found reference to a video but could access its link.
After turning X-ray off, you’ll be able to see that the top holes are skinned over. Select all of the geometry and run Intersect Faces. then select and delete those circular faces. Then make it a component or group.
Then run Solid Inspector2 again with X-ray turned on. You’ll see the following.
After clicking Fix All:
It makes me curious as to how you went about drawing this to wind up with these problems.
Thanks for the help. I will see if I can reproduce the results. The process was described in my reply before this one.
Something’s missing from your description, though. If you had drawn the circles on the top face and used Push/Pull to push them down, there wouldn’t be faces skinning the tops of the holes.
One thing you might consider is drawing the counterbored holes from one side. Makes the layout easier and since the hole and the counterbore are drawn on the same center point, they must be concentric.
The method you suggest did not work for me at the time - the making both holes from the same side. I do not know why it was not allowing me to do so. Maybe it was the size of the window and its zoom level.
I am very new to SketchUp so I have not figured out a lot of the necessities for making a good working model.
Thanks for all the help. I will work on reproducing my errors and try making both holes from the same side.
Another thing you should consider is initially drawing the model at an enlarged size, e.g. 10x and then scaling it down when you are done. The holes you are creating involve edges close to the size at which SketchUp can have difficulty creating geometry.
Follow this procedure to have your model solid:
- Scale your model X 1000.
- Select all by tripple click to the model.
- From the right mouse menu choose the Intersect faces with selection.
- Delete the circles that closes the holes.
- Select everything and make group.
In the case of your model, the edges for the circles are approaching the minimum SU can handle but for this model, there’s no need to scale up before running the intersect routine. It is a good technique to have in your bag of tricks, though.
I tried without scaling but only 1 circle has made the intersection.With 1000x scaling all circles made the intersection like it should be…
I did it when I made the screen shots and it worked perfectly without scaling. You can see that it was made solid after Solid Inspector got finished with the final clean up.
So,sometimes is working,sometimes not .Maybe it depend of a graphic card or Sketchup version ,who knows.But with scaling is always ok.
@slbaumgartner: I just tried to reproduce the errors using a simplified object, 100mm x 100mm, easy to use dimensions for construction lines as well as hole placement and the rectangles on the underside used to form feet once the Push/Pull tool would be used to raise the base.
It all worked out this time. In the process of working on the original model, I made some lettering (with shapes) which was recessed on the top surface using the Push/Pull tool. There was also quite a bit of making of circles, construction lines, erasing, repeating, using the Push/Pull tool, and that sort of thing. After I used the Solid Inspector2, I removed the lettering, which had gone to the edge of the top of the base. I had hoped that would simplify the process of turning my model into a useable 3D printable object.
There could have been numerous things that caused so many errors to crop up in the model. Unfortunately, I do not have the time to try to recreate the problems beyond what I have just tried.
As I said above, thanks for the help - the process for fixing the problems worked easily. I see somebody else included a GIF above, I will have to learn how to make one of those - that is likely the video I saw in another post.
By the way, I made the counterbored holes by making the small one on the top surface and the large one on the bottom surface. There were skins on the top holes that needed to be removed.
Regarding the problem with my model: I wonder if specifying dimensions of up to two decimal places when using a millimetre scale could produce some of the problems I had. There were a lot of lines drawn with lengths like 16.12 and circles with a radius of 1.82.
When drawing small models like this there are a lot of things that could go wrong (intersecting,solid tools operations,follow me tool…) To be on the safe side you need to scale the model .The easiest to calculate is X 1000 so when you see 1m you know is 1mm.
Working at a larger scale can be helpful sometimes. when I have to do that, instead of scaling up and back down, I generally start with a component (not a group) at the desired size. I make a copy of the component and scale the copy up leaving the original where it started. I’ll edit the large copy and when finished, close and delete the large copy. Zoom Extents takes you back to the original which will show the changes made to the larger copy.
If you do choose to scale up and then back down using Scale. make sure you use the same scale handle going both ways or your model will wind up at a distance from the origin. That could cause issues.
I have found the difference. If I use the “Intersect Faces - With Selection” then only 1 circle intersect, if I use the " “Intersect Faces - With Model” then all circles intersect like in your case.Never thought that those tools could have different results when selecting entire model.