dual_sport_dork 🐧🗡️

FreeCAD all the way.

The commercial CAD packages are all subscription schemes at this point which are designed around the dual purpose of extracting as much money as possible from businesses and nickel-and-diming hobbyists to death. The megacorporations that own them are actively evil and doing business with them should be avoided at all times.

Blender is not a CAD tool. You can bully it into kinda-sorta doing something that resembles CAD work with plugins, but that’s not what it’s for.

Sketchup is about the same caliber as TinkerCAD and LibraCAD is 2D only.

That leaves FreeCAD.

What your picture is showing is not stringing, it appears to be an utter failure of layer adhesion. That indicates to me you are printing too cold or, more likely, too fast for PETG. What you’re grinding against is most likely layers of the print that have not adhered to the layers below.

Try slowing it down and do a test print. See if anything improves.