Nozzle Width and Tolerancing
How does the slicer handle line width and tolerancing of perimeters? Does the slicer put the nozzle on the middle of the external edge line, therefore having ~0.2mm of extra material outside the theoretical part edge (assuming 0.4mm nozzle)? Or does it account for the nozzle/line width and put the OUTSIDE of the nozzle diameter on the INSIDE of the external perimeter?
Does that make sense? I can draw a picture if that helps 😀
Best Answer by bobstro:
The slicer will plan extrusions to stay within the boundary of the part. Of course, there are physical variations, so some variation exists, but outer walls tend to be within 0.2mm even without a lot of work, and moving parts can be printed with 0.1-0.2mm tolerances. I'm able to design threaded parts in Fusion 360 and print them without other adjustment.
RE: Nozzle Width and Tolerancing
The slicer will plan extrusions to stay within the boundary of the part. Of course, there are physical variations, so some variation exists, but outer walls tend to be within 0.2mm even without a lot of work, and moving parts can be printed with 0.1-0.2mm tolerances. I'm able to design threaded parts in Fusion 360 and print them without other adjustment.
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RE: Nozzle Width and Tolerancing
@bobstro
Okay cool thank you! So the tolerances after that are due to extrusion width and over/under extrusion then. How does the slicer account for less than nozzle diameter lines after calculating the extrusions between two lines? I.e. if I have a rectangle that is 1.omm wide, would it do 2 0.4mm lines and then 1 0.2mm under extruded line, or just try to smash in a 0.4mm line?
RE: Nozzle Width and Tolerancing
Multiple answers, depending on the specifics.
- In general, if there's a small gap between printed perimeters that is too small for infill, PrusaSlicer will use gap fill to fill the space. This applies to solid walls wider than a single extrusion. I can't recall if nozzle size is a limiting factor independent of perimeter extrusion width.
- A wall a single extrusion width or more will print as-is. Details and walls thinner than the extrusion width may print, but there's a lower limit to how small they can be before the slicer simply leaves the detail or wall out. Detect thin walls under Print Settings will try a few tricks, to a point. Any walls printed this way will be fragile.
Be aware that walls of varying thickness can be difficult if a mix of gap and sparse infill are used. This seems to be the issue behind the "buldge" defect (search that term) giving uneven vertical walls in some circumstances.
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He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan