.DWG to Sketchup, saved file size is too large

Hi there,

My client has a few hundred Autodesk Inventor models that they’ve exported to .dwg files. Upon importing them to SU, all edges that have a fillet applied have a ton of lines on them. If I go to hide/smooth these lines, they end up deleting the surface and you can see the inside of the model.

When I save a file (for example a simple outdoor table with three pieces) it saves at about 300KB. The competitors equivalent is about 20KB.

So I’m asking, is there an efficient way to import .dwg and save as a SU file that is extremely small in size, or should all these models just be re-drawn in SU? I’ve tried a few plug-ins (Clean-Up3, Polyreduce) with no results.

Thanks for any help!

Might you be able to share one of the DWGs so we can try it?

Thanks for the prompt reply Geo. I’ve uploaded the 3d .dwg file of a table. This file was originally exported from Autodesk Inventor, so there is nothing in it other than the wireframe. Thanks!

2983-0030 - SKETCHUP.dwg (129.2 KB)


9343 Edges
4496 Faces
A bit much for a simple 30” dia. pedestal table.
Model Info - File says the .skp I ended up with is 797.81KB

2983-0030 - SKETCHUP.skp (797.8 KB)

There’s plenty of high poly geometry that you could get rid of.
For instance, the three fasteners for the glider feet alone amount to ~7000 entities and the pedestal itself has two walls.

All that excess geometry, coupled with some rather odd overhanging faces about the outer edge of the top makes me think it would be faster and better to model it from scratch.

I was coming to the same conclusion. Since there will be a few hundred models to convert from Inventor to Sketchup, I was hoping there would be a quick and easy way to get it done, but I guess modeling them all from scratch in SU is the optimal solution.

Thanks for taking a look at this and providing your thoughts, I really appreciate it.

I got a different edge and face count than George, using Inches as the import unit and checking the “Merge coplanar faces” box in Import Options:

Some missing small faces, but I have seen worse. Sketchup file about 660 KB. It is the numerous small roundings that bloat the file size.
I wonder if Inventor could create directly a DWG export file in a polymesh format instead of solids, and if, in that case, it had settings that could be used to make a more coarse mesh. It seems that the SketchUp importer puts quite many segments to a circle and arc when converting imported solid objects, and there is no way an user can influence this (FR?).


The reason for the difference is that when I imported the DWG I set the import units to Meters.
Then, I scaled down to Inches.
Like you, I checked Merge Coplanar Faces along with deselecting Preserve Drawing Origin.

I just tried it with import units set to Inches.
This is what happens to the tiny geometry in the three fasteners for the glider feet.
Many missing faces.

These odd extra faces on the table top are still a mystery to me.

Yes, simplifying the DWG tends to yield better results in SU.

In Inventor, I exported directly to the .dwg file format as a 3d object. When I open this file in AutoCAD, I don’t see anyway of making the model more efficient. Perhaps it’s just the nature of moving from one software to another.

I also tried converting the model in Inventor to a surface only model. When I import this into SU, nothing loads. I’m wondering if the data written by Inventor about the surfaces are not really readable/compatible with SU.

did you try a dwf export/import, I always thought it was preferable?

but I am on a mac…

did you try a dwf export/import, I always thought it was preferable?

I did not since I don’t believe SU can open .dwf, only .dwg/.dxf?

sorry dwf was in fact a typo…
I had meant ask about dxf as I had more ‘luck’ with those in the past…


I just tried a .dxf file and it results in the same scenario as the .dwg. Thanks for the thought though, I was getting hopeful!

It might be that Inventor is creating NURBS-based surface objects. I haven’t tried in the latest releases, but in prevous ones Sketchup ignored those. It would be best if Inventor could export face geometry.

DXF is identical in content to a DWG file, but it is an ASCII text format, whereas DWG is binary.


need to know DWG files version 2014 and above very, very big and it is of course also affect the SU file, in my opinion should export DWG files by converting the first on the version below and the most stable is the 2000 version.
hope it is useful

There is no DWG file format version 2014. AutoCad versions 2014, 2015 and 2016 all use the version 2013 DWG format.


save as DWG version 2013 or after to DWG version 2000

I tried exporting the Inventor 3D model as AutoCAD 200 version. The results were the same.

Thanks for all the help on this one. Ultimately I decided there just wasn’t a clean and easy way to do this and the models get extremely complicated for the other products, so I’m having a co-worker re-draw everything in SU and we’ll see how it goes.

Thanks again!

can u help me convert this autocad file to skp … its a 3d of a large URBAN DESIGN project[Uploading: 3d fort kochi.dwg…units : meter


Not sure about size limitations - as there usually is with free
things - but you could give a try - and set
your output file as .dae.