PrusaSlicer 2.2.0 : Adjust infill thickness?  

RE: PrusaSlicer 2.2.0 : Adjust infill thickness?

Infill is just that, infill.

You are asking for something different, internal reinforcement.

The simplest way to do this requires some backwards logic:

Design your 'solid' model - though you know that in fact it will be nearly hollow when sliced.

Design your internal supports as wafer thin (0.1mm eg) cuts through the interior that do not reach the outer edges.

Export to the slicer.

Set your print to have the required number of perimeters or create a modifier if this applies only to part of the object.

When you slice, check the layers preview.  You should find that the slicer has counted the cuts as external perimeters and surrounded them with plastic - just where you wanted the extra material.  The rest of the 'solid' model has only the usual fine infill.

Hth, Cheerio,

RE: PrusaSlicer 2.2.0 : Adjust infill thickness?

Posted by: @oleev

As far as I experienced it, the infill pattern is always made of only 1 line.

That is correct. However, you can set a different extrusion width for supports. If you're using quality nozzles, you can go up to roughly 200% of your nozzle size. Finish may not be the best, but just fine for encased infill.

However, infill doesn't contribute as much to part strength as perimeter count. Add 2-3 perimeters for best part strength.

If the part allows it, put some holes through the areas that need strength. The extra perimeters around the holes will add considerable strength and rigidity. 

RE: PrusaSlicer 2.2.0 : Adjust infill thickness?

"If the part allows it, put some holes through the areas that need strength. The extra perimeters around the holes will add considerable strength and rigidity. " A great trick Bob, thanks.

RE: PrusaSlicer 2.2.0 : Adjust infill thickness?

@diem

Great approach to archive internal reinforcement, exactly at the wished location! I am looking forward to try it in Fusion.

Thanks for the precision of your precision, it brought me a good step further and spare me plenty of time!

RE: PrusaSlicer 2.2.0 : Adjust infill thickness?

@bobstro

Adding some holes : great trick for a quick reinforcement ! Tks so much, i will use it often I think!

RE: PrusaSlicer 2.2.0 : Adjust infill thickness?

@diem

This option is available in Cura, called "infill line multiplier", which leads to a huge amount of polygons and disrupted infill geometry. I guess this might lead to a poorer strenght / material ratio in the x and y load, but a way stronger z stability while using the right pattern. This could be relevant at some point anyway, as a "niche feature", don't you think?

RE: PrusaSlicer 2.2.0 : Adjust infill thickness?

@oleev

I must admit I've not tried it in Cura.

The main advantage of the method is that strength is greater aligned with the lay of a perimeter.  You can direct it exactly as needed.

For extra strength in the Z direction the best I have found is to leave a square sectioned vertical hole and then print a reinforcing rod horizontally to slide into it.  This works best with holes wide enough to tidy up with a needle file and close tolerances.

Cheerio,

RE: PrusaSlicer 2.2.0 : Adjust infill thickness?

@diem

One more good trick! Nice!
One last thought : I was also expecting to be able to fine tune the stiffness of a flex / TPU vibration absorber (bumper, sole) with this parameter, but I guess that the infill pattern itself plays a bigger role (gyroid or cubic). And this belongs already to a new thread 😉
thanks for your time!

Regards!

RE: PrusaSlicer 2.2.0 : Adjust infill thickness?

For flex infill you will notice greater stiffness and 'bounciness' when using closed-cell infill: Cubic / 3D Honeycomb; you can tune the effect to some degree by varying the percentage.  For softness use a more open infill and use modifiers to add ports (of zero perimeters) to allow air in and out.

Cheerio,

RE:

Here is an interesting video showing Infill line multiplier: