Adjusting infill density in 3D, not just layer by layer

[dtown]

Has anyone come up with a way to adjust infill density for a specific region within a model, not just for specific layers? A good example would be the T-Rex shower head. I would like to print the nozzle itself at a high infill, and keep the rest low to save time/material. In this case, I would want to adjust the infill within a specific rectangular volume within the model. Any Ideas?

[Fred B]

I would probably try tricking things by cutting the file in two. Create 2 STL's and use processes for each.

Alignment of the parts will be critical.
The parts might not adhere to each other well (probably need to overlap them a little).

[dtown]

I will have to try that... I guess I will use netfabb Basic to cut up the model, unless anybody has any easier, free suggestions. I'll post my results when completed.

[dtown]

I just had time to think about this again....

1) Splitting the Mesh

I found that the easiest way for me to split the mesh was in FreeCAD. I could look down on the model in the x-y plane and draw the profile I wanted to cut, rather than having to make multiple plane cuts. This produced two parts that shared a common cute line:

split in freecad

2) Repair

Then I used netfabb's web service to repair the resulting to meshes.

3) Import to S3D

So I imported both files into S3D:

import to s3d

Then I gave both models the same x-y offset which lines them up perfectly, and makes them look as though they are one part (at least externally)

adjust xy offsets

To be continued.....

[dtown]

After importing and aligning the skull as two separate meshes (one for the skull, one for the shower nozzle) I have to define the processes.

I will define one process for the skull and one for the shower nozzle. The only difference between the two processes will be infill density, and they will be applied to each part separately, as shown:

applying a process to each mesh individually

Once I click "Prepare to Print," I select both processes and continuous printing mode.

Prepare to print...

Then my computer pretty much explodes. This computer isn't complete junk, either.
It will slice within a few minutes, and it will parse the g-code for rendering if I give it about 20 minutes. But it gives an estimated print time of 169 hours...

I'll post this, and attempt to slice.

[dtown]

So in the process of making this tutorial, I must have done something differently. But it worked!

It took about 45 seconds from when I clicked until the g-code preview was available:

g-code preview

However, the nozzle and the skull don't appear to be contiguous:

gap between nozzle and skull

[dtown]

So I went back, and bumped the nozzle into the skull by adding 1mm to the y offset:

adjusting nozzle y-offset

I think this worked. Now when you preview the g-code, it looks like they will probably adhere pretty well:

Top View

Side View