Is it possible to compress .3dm and .stl files?

Hi, I’m trying to submit some 3D Printing files to my university however the job submission folder caps out at 25MB is there any way to compress .3dm and / or .stl files without having to split the components?

Hello - for 3dm files, SaveSmall and save a version without plug-in data or textures.

You may be able to fine tune your detailed mesh settings for the stl output - see


1 Like

Okay awesome, thank you. Does saving small have any effect on the model?

Hello - see


1 Like

Gotcha, Cheers :slight_smile:

I changed the tolerance through properties < Units and set it to .01 rather than .001 as I had before. This doesn’t seem to have effected the .stl file size whatsoever. Is there something I’m missing.

Thanks for the help

Hello- document tolerance will not affect file size after the fact. I’m not sure why you are changing that, what you’d need to do is mesh the object for STL output with some attention to the meshing parameters.


I changed the tolerance as this seems to have reduced the file size from 36MB to 26.4MB. I also set customs settings and lowered my density to 0.01, and have experimented with setting density to 0.1 but this doesn’t seem to effect the file size. I am unsure as to what I should set my other values to (this part seems fairly complicated) do you have any parameter recommendations?

side note: Didn’t realise it had affected file size before

Just changing the tolerance doesn’t do anything, it’s literally just changing a number until you actually start building more geometry, and I wouldn’t recommend loosening it up just for this.

Look at the links given about meshes for mesh settings, you can use the Mesh command to manually mesh objects and see interactively the impact of the different settings.

yeah I’ve been reading the FAQ’s but its fairly complex. I meshed the object using the fewest polygons possible. This has reduced the file size. Not sure what else I can do to further reduce file size as I’m struggling to understand the effects of changing the custom mesh parameters in properties

Hello @1606739
I find the best non-destructive compression workflow is to:

  1. Save the 3DM File using the Save Small option.(Which is non-destructive and will just take some processing time when opening the file again to rebuild the display meshes)
  2. Use the free 7Zip program ( to create a .7z compressed file. I find that 7zip can compress a 3dm file into a .7z format to be sometimes about 1/5th the size that the ZIP algorithm/program achieves on 3DM files and overall achieving compression of 10x or more from the original 3DM file size. Note that 7Z compression is non-destructive so there is no affect on the original file… Regards MichaelVS

Well, 25MB is a pretty restrictive limit these days.