Any tips for simplifying CAD models? I have a CAD model imported into Blender in STL format. This was a STEP file exported in STL format from FreeCAD. Without making any modifications it looks like this:



Base model has 38, 326 faces.

So far these are the steps I have been using to retopo:


Select all verts and remove doubles (face count (fc) = 34,786)
Select all faces and Alt + J to convert all tris to quads (fc = 21,650)
Add Decimate Planar modifier and adjust Angle Limit to get good balance between face count and "look" of the model. Usually around 10 degrees is good enough (fc = 2,755). Now the model looks like this:






So there is still alot of geometry around the holes and other finer features. Apart from making the planar angle more aggressive and manually removing verts and replacing with new faces, which is quite time consuming, are there any other tricks I can use? Ultimately this will be exported as an FBX and used in Unity.
Yeah, you've actually done a decent job.
Only trick I might add is an Edge Split modifier.  

It'll crisp the boundaries a bit,
especially around the circular parts.  

Believe you need to apply it before decimation,
if memory serves correctly...
so you might need to start anew to see its effect.