Shop Owner Challenge Day 13: Use Netfabb to Save your 3D Models from Rejection

Over 100 people took our pre Shop Owner Challenge survey and the results were clear: the biggest point of frustration with Shapeways is having a model rejected. Our Customer Service team is dedicated to helping you resolve these issues. Today, Andrew, a very helpful recent addition to the team teaches you how to use netfabb, the same program we use here at Shapeways, to optimize your models printability.

Open your model in Netfabb. Netfabb can only open .STL or .OBJ files. If you need to convert to these file types you can use Meshlab, see our tutorials section for details. This model was made with the 2D to 3D Converter.

TIP 1: The Netfabb Information Side Bar

Click on the model so that it turns green. on the bottom right side bar, you can find some important information about your model.

1: bounding box dimensions, This is how long, wide and deep your whole model is.

2: Volume, this is how much space (in cubic centimeters) your model occupies. This is useful because it is what Shapeways will calculate the price off of. Notice it reads — right now, because something is wrong with the mesh.

3: Area this is relevant for ceramics, because it is how we calculate that price (square centimeters)

4: triangles, These are the smallest shapes that a 3D model can be described with. The more shapes, the more complicated and the larger the file can become. The Shapeways website will accept uploads up to  1,000,000 polygons or 64mb

5: If you see the red, triangle ! sign, this means there is something wrong with your model that will prevent it from printing properly. But fear not, you can use the red Repair tool + in the top toolbar.

TIP 2: The Repair tool 

Click the red + sign on the top bar, this changes your tools to relate to the Repair tool. Notice that the side bar has changed and the Part navigator now highlights the Repair tool.

In the Statistics side bar a few values are red, click update to see what they currently are.

1: Shells means how many separate objects 3D are in this file. They may be separated by space or overlapping.

2: Invalid orientation means that the normal value of a face is in the wrong direction.

Think of a 3D model as being a really cool origami made out of paper that is infinitely thin, as an individual face has 0 thickness. A face can only “face” in one direction, so if it blue it is “facing outward, and if it is red that means it faces inward. If there is red facing out, the printer will get really confused, and the model can’t print.

3: Holes means the mesh is not a cohesive, continuous surface, it is not “watertight”. Back to the origami analogy, because faces of the model are infinitely thin paper, the space between them is the thickness. If there is only one piece of paper without another across from it, there really isn’t anything for the printer to print, again, which will confuse it.

4: Border Edges that are not connected (although they may be overlapping) will be yellow, these count as along holes too .

1: Click automatic repair to fix these problems, and if there are are overlapping faces, it will merge them together such that the whole model has a pristine, continuous shell.choose either default or simple repair.

2:When you are sure you are done click Apply repair to finish. It will ask if you want to discard, say yes but make sure that it hasn’t done something terrible to your mesh, as it will occasionally do something strange if your mesh has many of these problems. Notice that the values for shells, invalid orientation and holes should go down, preferably to the lowest number possible. Don’t fret yet if this doesn’t work perfectly, when you order your model to print we use a similar but more fancy fixing tool called mesh-medic.Now that your Mesh is repaired, click on the file name to return to the main toolset.

Before:

After:

Tip 3: Measuring sidebar menu

We need to check if the model meets our Design Guidelines for the specific material you want to print in. Remember that every material has its own unique Guidelines our engineers use to check your model, and we have these on the guidelines page in each material.

Click the blue measuring stick in the top tool bar to go to the measuring menu.

1: In the sidebar will be all the measuring tools, the first measures distance.

2: These are options for what part of the model these tools will “snap” too to make precise measurements easier. Choose face, vertex or edge.

3: The point to point tool works just like a measuring tap. Click the first point for where you want to start measuring, and click again any other location on the shell to measure the distance between. This tool is great for finding the clearance between shells too.

4: The Wall thickness tool is perfect for finding out just how thick each wall is. Clicking any face will measure the distance to the next face. Using this tool you can easily find out if your design meets the minimum wire, wall and detail Design Guidelines.

After measuring this model, it does not look as if it will meet the Design Guidelines, the wires are too thin, and if looking at the bounding box, the model is too small.

You can use the scale tool to change the dimensions of the overall model. Some software packages don’t export at the accurate size of the model, but you can use this tool to change the model to whatever dimensions you would like. Go back to the main part by clicking on the Part name in the context menu (Its the white space ofter the Sidebar Menu) and click the tool that looks like this: 

1: Choose The target size of any axis

2:Changing the Y to 10 will change all the other axis if..

3: Fix Scaling ratio is selected.

Notice that the bounding box went up, the volume is much higher, but the number of triangles are unchanged, because you only changed the dimensions of the model, not its geometry.

Now that the model is bigger, we can check if it meets the Design Guidelines again.

Using the measuring too, this time all of the wires are much thicker.

Tip 4: Cutting tool

If you want to get an even better look at how your model is made, you can use the cutting tools.

1:These sliding bars represent the X Y and Z axis. Click where you want to slice on the range of the slider, 

2: click on the rectangle to the right to decide of you want to remove left or right of this location.

3:if you want a red line or no line to show where the slice is taking place.

This tool works wonderfully with the measuring tools if you want a better view of the model without anything in the way, and if you want to make sure that all the faces are oriented correctly (red should be inside inside).

Tip 5: Design Guidelines

To make sure this model will print, I am going to check my model against the material guidelines for each material I want it printed in.

It looks good in White Strong and Flexible, but won’t be thick enough in polished and dyed.

It looks like it has too thin of wires to be printed in Full Color sandstone.

This is how we check each and everyone of your models, every time you order them. We do it all by hand right now, so you can imagine it takes a lot of effort. If you do this as well, you can fix the problems we may find before you order, and safe yourself and us a lot of frustration.

If you have any questions just ask at Service@Shapeways.com

Hope this helps, Shapies!