Preparing for 3d print

I have small architectural model. I want to 3d print it with full infill. What is the best method to fill in the model? I Have searched casting but I did not find anything. Best solution would be a grasshopper one.

sample.3dm (3.7 MB)

What does full infill mean?

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when the empty space is filled up

Have you tried slicers, what is the problem with them?

they does not fill up the empty space. Check the image

Just close the solid by creating a flat surface across the base and removing the internal surfaces…

Explode the polysurface into separate surfaces.
Delete the internal surfaces
Create a planar surface to close the base
Join all the surfaces into a closed polysurface.

Then you can set whatever infill you like in your slicer.

I wouldn’t use solid infill as it will be a complete waste of material and probably warp as it prints.

Go for 15% - 25% max infill

unfortunatelly the model is not suitble for this method.

why not?

it is a mesh and there are no separate surfaces. check the model

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Ah, it’s loads of separate meshes that won’t boolean union together :frowning:

You are going to have to use supports to print this anyway, why not just support the whole underside of the model and leave the supports in place?

If all the separate meshes would boolean union together, you could have closed the mesh after removing the internal faces.

I reckon your slicer is going to have a problem with this anyway because it is separate meshes.

I’m assuming you are not the designer and cannot just do it in polysurfaces?

Do you have several like this that you need to print?

Maybe Shrinkwrap in Rhino8 would do it?

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isn’t this the ideal testcase for ShrinkWrap?

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Please post the Rhino surfaces model you have pictured, not the dumbass mesh.

Shrinkwrap seems to work okay in V8 here, the best solution would be to go back to the NURBS model and do the minimal cleanup needed to union the pieces and remove the unneeded wall thicknesses, it would take like 10 minutes.

I though there is a simple tool already existing, prepared for casting purposes, to fill out an empty space like that.

I think that would work if you had a nice clean unioned mesh or valid, closed polysurface.

You have several meshes that don’t join together very well. Presumably, this design technique has arisen from model manufacture from cardboard or wood? I think you should change the design method to suit 3d printing manufacture.

Rhino 8 has ‘shrinkwrap,’ exactly for this purpose, but you would still have to add in surfaces to close off the volume you want to create. You expect it to figure out you want to fill in the giant hole in the bottom?

There is not any other magic ‘prep this model I thoughtlessly built’ for 3d printing, modeling for 3D printing is MORE DEMANDING AND FINICKY than other manufacturing processes, which are so old they were designed to work with the junk data from 1980s CAD systems!

I disagree, it’s just different to this process. I don’t see it being harder to design for my 3d printer or my CNC or if I want to make something by hand.

This method has probably worked for someone for years but is not suited for 3d printing.

CAM software doesn’t strictly speaking need a ‘clean watertight solid.’

Neither does every slicing software. They can all deal with poor quality STL meshes to a certain degree, They can tap into the online Microsoft service for repairing meshes, for example.

There are a number of problems with this geometry that make it unprintable. Here’s a pic of the geometry exported as-is from Rhino as an STL file and imported into the Orca slicer and sliced for 3D printing:

Orca reports the following error when slicing:


What this means is there is at least one area that sticks out and is not connected to anything underneath it. This means that although the GCode produced by the slicer will physically print, something won’t be right with the final result.

Another problem is the geometry has no bottom surface:


This will not stop the geometry from printing, but without a bottom surface the print will require gobs of support material to hold up the top surfaces. Gobs are hard to deal with. A better solution is to add a bottom surface and let the slicer generate the required inifill. There are some pretty fancy infill algorithms now that generate a surprisingly small amount of infill and yet produce good results.

Here are the “floating cantilever” sections that will require separate support material no matter what:

I tried to get this geometry into GH8 but could not do it. My guess is that GH get confused because the 3dm file is comprised of multiple meshes that may or may not be connected. It looks like there are a zillion separate surfaces in the 3dm file, and as previously mentioned, for 3D printing they should first all be joined into a single mesh or surface.

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