Redoing circles and broken structures


I have used SU for 18 months now Whilst many of it’s atributes are exceptionaly easy to use I find myself spending hours redoing stuff that SketchUp brakes. Circular holes in a model that change to plain circles when you move or replace the surface that they are on and have to be manually re-done or where you have to draw a line in a circle segment to make it register on the connecting surface. But worst of all when you draw a flat surface and for some reason it will not fill with colour. Then you have go over it again and sometimes draw new lines across corners to force it and then delete the lines to get a surface. This is where i spend most of my life with sketchUp, repairing things that it brakes. Seriously chaps unless I am doing something basically wrong I wonder if Sketchup is actually a saleable product. It’s driving me nuts.


Much of what you describe sounds like you need to practice using SketchUp’s inference system. If you watch the inference tips, it is actually easy to keep things aligned.

To keep a collection of things perfectly coplanar, first draw a large rectangle at the desired orientation and location. Make it a group so it won’t interact with new geometry. Then draw the next set of objects watching for the “on face in group” prompt from the inference engine. If you do this, the geometry will remain perfectly on plane. You can delete the reference rectangle group when you have drawn everything that needs to be on that plane.


I will do that. Thank you.

My problems are usually to do wit cylindrical or solid parts extracted my using the solids tool. It is truly bizarre. You see I am not trying to get it right in the first place (I have learned that) its changing a surface sometimes just back to how it was when I haven’t moved the original structure. So if I have to rejoin two circles as if partially extruded when I join the existing points it will not fill in the planes on some sections. Others on the same two curves join up perfectly and immediately but some just won’t


Could you upload an example so we can see exactly what is happening?


This is a simple one and you will see I have already fixed a couple of places (white) But sometimes I spend hours on this type of thing. All I have done here is subtract one solid from what is left. If I want to extract any more I have to fix every single imperfection.SUTest.skp (1.3 MB)

Try to fix the bottom missing stripe. That will make you laugh


Try to do the same ‘Solid’ operation(s) on these solid objects when they are 10x or even 100x the initial size.
Now many of the edges are near or less than SketchUps limit, making operations with Solid tools difficult or even impossible.


Thank you for that

So you think it is just a scale problem? I think I am working on highest res. Dimensions come up to 6 decimal places. It would appear that I am working with the wrong tool I guess


It depends on what you are making. Is the object for 3D printing?

SketchUp can’t deal with edges less than 0.01" or 0.0254mm
Vertices may merge.
Yes, scale is your problem, unless you can get by by working with scaled components.


Not a matter exactly of ‘resolution’, just of the way that Sketchup was designed, and its original purpose - architecture, at scales from house to city.

The smallest dimension that you can draw directly with Sketchup is of the order of 1/100th of an inch. Your smallest edges, of segments of small arcs, are near or below that limit in some cases.

SU will work fine for small objects, IF you draw them at 10x or 100x or 1000x times ‘real’ size. For example, use metres to represent millimetres, and work at 1000x full size.

If they are (for example) to be used for 3D printing, you can then scale them back down again AFTER you’ve finished drawing them big. SU can keep track of EXISTING geometry at small sizes, but can’t create new geometry reliably at very small sizes (for example, the internal clean-up routines when drawing new geometry, I understand, merge points within about 1/100th of an inch of each other).

PS. I stand in part corrected - geometry smaller than 1/100th of an inch, not 1/1000th. Thanks, Wo3Dan.

Above edited to fix…


No problem. I keep forgetting too. And I even wasn’t sure 100%.
I’ve set up that model many times to check what the limit is.


Despite the scale, you are using Layers incorrectly.
You have raw geometry spread over three different layers, this won’t work.
You have some edges on one layer and the faces they form on another layer.
All raw geometry should be on Layer0.
Only Groups or Components should be assigned a layer purely for visibility purposes.
Layers do not separate geometry.
Groups and components Do separate geometry.


Thank you all. Very helpful.



I have scaled up the attached. Just take a look at the ridiculous lengths I am having to go to to get this to turn into something I can extrude. I have done all suggestions but still have same problemTest.skp (118.8 KB)


Somewhere along the way you have got the edges slightly out of line, so the shape isn’t planar and therefore won’t form one clean face.
There are various ways to make things planar. I have used vertex tools. As you can see, even scaled a lot down it works.
It can help to always draw your edges on a face and remove the excess.


That looks great. How do I find vertex tools? Can’t see it anywhere and your video (Brilliant) is a little quick so I cannot see what you are selecting to start the process


It’s a ThomThom extension. Look for it on the Extension Warehouse (note: it is not free).

Also please note that while this extension can do many very useful things, including fixing out of plane vertices, it is ultimately better to avoid the issue in the first place by paying close attention to the inference snaps and initially creating a reference face on which you draw the edges while watching for on face inference.


I’m with @slbaumgartner on this, I only used Vertex Tools, which is a commercial plugin, as an example of how a fix demonstrated that the edges were out of alignment.
It’s far more important to develop a workflow for yourself that creates clean geometry.
I use Vertex tools a great deal, but rarely to make things planar.


The thing that really bugs me is that this kind of problem occurs on a perfect finished product. Then when copying it or mistakenly deleting the tiniest section it will not repair. If I had done it wrong in the first place then yes tis my fault. But I only have to join something move something or try to replace something and that’s it it goes bad. The sample I sent was just a perfect section until I deleted the tiniest section at the top that needed modification. Could not fix it so I scaled it up by 1000 as advised above then you can see what happened to it. Drives me nuts.

Thank you all again. Derek


Can anyone explain why this dreadful program does this. All I have done is added Test.skp (923.3 KB)
a shape and pulled it into the body of the component and all these lines appear. The Yellow one was a copy of the original and I am working at 1000 times scale.

One minute there are no problems and them all this stuff. I have just made two solids checked them so they are clear of any faults. Put them together and one says not a solid. If I take them apart they are both solids. What on earth is going on with this program. I’ve had 12 months of this and it always happens right at the finishing stage. 4 hours today achieved nothing.


As I mentioned in my earlier post, you are using Layers incorrectly and that is at the root of all your issues.
If you stop trying to use layers most of your problems would disappear.