Sketchup is really slow and "not responding"

I use Sketchup all the time. I import AutoCAD 2D files into it and make them 3D. Every once in a while there are a lot of small circles on the drawing and Sketchup will slow way down and repeatedly say “not responding”. My graphics card says it’s only using 10%.

What can I do to speed this up. I haven’t even started to 3D this file yet and it is already slow. If I keep going the way it is running now it will take me 20-25 times longer to finish this project.



“Not Responding” means that SketchUp is busy doing something and won’t respond to further input from you until it is finished. I expect it’s going through the imported geometry to make sense of it. I’ll guess there are huge segment counts for the small circles in your import. Sharing the CAD file would help us give you better guidance.

Best practice would be to use the imported CAD file as a guide while you redraw the thing with SketchUp’s drawing tools. Once you’ve finished delete the imported CAD component.


Dave is correct. I can guarantee the speed is a result of that acad file.

The only ACAD file I import is Topographic surveys and the number of segments on the contours is typically staggering! Just like anything, ACAD can be ■■■■ in/■■■■ out.

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The reason to import the CAD files is because I can draw it quickly in CAD. It would take me all week to trace it in Sketchup. I already need to scale models up x48 just to let Sketchup handle the small radiuses. I have to keep jumping through hoops just to get this program to work.

Is there a program that can handle AutoCAD files?


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Long Island boxcab x48 N scale 2.dwg (114.1 KB)

This is the file I’m trying to import.

Why 48 time? That seems like a strange value.

Might be that learning more about using SketchUp would alleviate that.

SketchUp isn’t tolerant of the garbage often found in ACAD files.


What is that you need out of the model that makes you switch to SketchUp in the first place?

My computer doesn’t seem to have any problem with handling that .dwg file.

Are you intending to 3D print this thing? If so, scale it so you can work with units set to meters. Treat inches as meters while you are modeling. When you export to .stl, make sure the export units are also set to meters. When you import into the slicer make sure it’s set to inches. STL files have no units so you can work at meters and there’s no need to scale down before exporting the file.

x48 is where Sketchup will work best. For instance when making a small circle Sketchup will say it is too small for that many segments. So if I scale the whole drawing up x48 now Sketchup can handle it. Sketchup has so many limitations.

What I want out of Sketchup is take my 2D drawing and make it 3D. I have been using it this way for 3D printing for about 3 years now.


My computer has no problems with the file, Sketchup has a problem with it.

I run into problems when scaling in Sketchup. Sketchup will lose parts of the model. This is why I start with the file already scaled.

I guess the solution might be to clean up the AutoCAD files?

Is there a way to do that?

Why don’t you try what I suggested?

The DWG is not to full scale or then it uses some drawing unit unknown to me. The cab doors are about 22 units high.

He’s working on an N-scale model.

I just don’t understand meters. I would have to sit here with a calculator and spend all day long to draw something. That CAD drawing I uploaded took me about 3 hours to draw.

Plus like I said when I try to scale in Sketchup bad things happen. I export the .stl files and shrink them down 48 times using Netfabb. I don’t size anything in the slicer.

I have been doing it this way for years now and just don’t have 12 months to learn a new way. 90% of the time it works great. I think it is all the rivets in the CAD drawing that are screwing up Sketchup.

It is a N scale drawing that was enlarged x48 times.

This is a similar model that gave me problems. All those rivets.
Google Photos

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To me the dimensions make rough sense if I assume that it was drawn in 1:87 scale.

No you wouldn’t! You seem resistant to the idea of an easier way to work so I won’t push it.

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Yes I know sorry about that. I would have to search for how to change the settings to meters. I made all those settings long ago and don’t ever use them so yeah I would need to re-learn it.

Besides that. When I import a CAD file I first need to “explode” it. This file takes very long to explode so I’d imagine it will keep on being a problem.

Sketchup has so many limitations, needs plug ins to do basic stuff. But all other options want you to pay a crazy yearly fee. I’m not a business, just a hobbyist.

Depending on the resolution of your 3D printer it might not make sense to try to cram more segments to the rivets than necessary. You might try making a small test model with rivets with, say, 8, 12, 16, 20 and 24 segments and see if you can spot any difference in the 3D printed result at that scale.