That is not correct at all. Go look at the gcode that is produced. The toolpaths are NOT positioned directly on the edges of the model. If they were, everyone's parts would always be one extrusion larger than intended (i.e. around 0.5mm larger). And I guarantee you this is not the case. There are many people here, including myself who routinely print parts within 0.01mm tolerances.corry wrote:Yes, it positions the *TOOL* *EXACTLY* where the model defines it. Plastic comes out *BOTH* sides of the nozzle. Place a 3mm hole in an object at 0,0. Note the min/max x/y are at 1.5 and -1.5. With an extrusion width of 0.48 holes will now be a maximum of 2.42mm. Add in the arc issue and it's less. Add in a bit of plastic shrinkage it's less. By for though the largest contributing factor is the extrusion width! Seriously, it's not rocket science and needs fixing!
You need to look more closely at the toolpaths. They are automatically offset away from the edges of your STL file so that only the very outer side of the extrusion lines up with the edges of your model. It works exactly how it should.
If you are seeing the holes end up smaller then they should be, then it's either because of your STL file tolerance or over-extrusion. The software is placing toolpaths exactly where it should based on the model you give it and will extrude exactly as much as you tell it to.
If you still disagree, why don't you post a factory file that includes a simple model with a simple hole that you feel is being sliced "incorrectly". I'll be happy to walk you through it.