Internal walls and clearance for moving parts?

Hi,

While I´m waiting for my 1st printer, I´m busy designing lots of stuff. I´ve got 2 questions now, where I cant really predict the slicing/printing behavior.

1) Does it matter if there are walls within the model? Or will the cube automatically be filled with what ever percentage infill you give it in the slicing stage?
I can imagine sometimes it makes sense to have a predefined structure within an enclosed space and sometimes it would make the design process more complicated when you wanted to delete all unnecessary interior walls.

2) What is an average value of clearance when designing moving parts? (FDM printer without 2nd head for support material) Is there a way to define the moving parts during the slicing or shall I give moving parts a standard clearance of 1mm and the slicer will add support I can later break away?

Cheers

1. Depends on the overall structure of the model. You generally do not want internal walls.

2. Depends on your nozzle diameter and layer thickness. Slicing does not calculate for moving parts, you need to model with mechanical clearances.

ok thanks for the fast answer

1. do you know if polygon reduction software removes inner walls. or do i have to design like this from the start?

2. i can imagine i have to test the actual clearances out with my individual printer and material or is there a rule of thumb?

sungod3k Wrote:
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> 2. i can imagine i have to test the actual
> clearances out with my individual printer and
> material or is there a rule of thumb?

I have been using 0.5 mm clearance (total gap) for rougher parts that should fit together easily without sanding and 0.25 mm clearance for a tighter fit in finer parts.