Help for a newbie?

Hi everyone,
Hoping someone can help. The issue:
I've modeled in SketchUp a prototype product for a client. The product/model consists of the front and back pieces of a container that will house a bit of electronics. I exported a Collada file from SketchUp of the model, and used Meshlab to generate the .stl file. By the way, I'm on a Mac using SketchUp Pro.
The Netfabb analysis tells me that a surface is not closed. I sent the .stl file to Shapeways and sent back to me a screen capture of their view of the model. Shapeways believes there is an area in the front cover where a thickness if 0 mm.
I'm lost on how to correct this. Any help from someone here that is way more experienced with this would be much appreciated. I've attached here the .stl file, the screen capture from Shapeways, as well as a screen capture of the model from SketchUp with a section view shown (just to show the construction of the front cover)

Thanks in advance!

-Greg

If you load that stl into netfabb studio basic, you should see a big red warning triangle next to your model. Choosing "new analysis" (the blue icon next to the red cross in the menu bar) will then tell you that your model has 13192 triangles, holes and shells and no closed surface. This is obviously not good.
Next, click on the red cross to access the repair function - the image of your model will now be covered with a yellow mesh when "highlight holes" is checked in the table (which I believe it is by default). Now click on "Automatic repair" below the table, and choose "Default repair" from the dialog that appears.
The yellow mesh will vanish, and if you click "update" in the table you will see the values change to display zero holes and only two shells (the box and lid parts of your model). Click on "Apply repair" and confirm that you want to discard the original model. If you now run the analysis again, it will show 2 shells, some 4100 triangles and zero holes and state that the surface is now closed everywhere. Open the Part menu now to choose "Export part" and save the repaired model. This should now be good for uploading.

BTW stonysmith has written two nice tutorials for less trivial netfabb usage that can be found on his website (stonysmith.com)

mkroeker,
Thank you VERY much! Much appreciated. Worked perfectly. Is an STL the preferred file type for upload to Shapeways?
Also, thank you for the netfabb tutorial link. Will check it out.

-Greg

Yes I'd think so - unless you need color in your model, which STL was not designed to handle at all.

Greg, check out the Solid Inspector and STL Exporter plugins in the Extensions warehouse. With those two plugins you can do everything inside of Sketchup. For more detailed info, you may find this article useful: http://www.mastersketchup.com/8-tips-for-3d-printing-with-sk etchup/

Yep, Solid Inspector is one of the most useful Sketchup plugins when designing for 3D printing. I'd add that the default Collada .DAE export format of Sketchup is directly uploadable by SW; using a scale of 1:1000 i.e 1mm physical = 1000mm in Sketchup allows the SW uploader to scale automatically.


Steven

Thanks. I do have STL Exporter, but noticed that Solid Inspector required the install of something called TT_Lib2? I was pressed for time and didn't have the time then to investigate further.
-Greg

Steven,
Good to know about the direct upload of .DAE files. Can you clarify the bit about scaling for me? If my object in SketchUp is 2.5inches across (actual size), where and how do I modify the scale to ensure that my printed Shapeways piece is 2.5inches across?

My apologies for the dumb questions...

-Greg

Another thing with the STL exporter which is neat is that you are able to pick the whether the model scale is in inches, millimeters, or meters. In other words, if you pick meters, the 2.5in model will now be 2.5 meters for Shapeways.

You can check the actual dimensions of the model by clicking on "Edit Model" of your desired model and examine the dimensions under the Model tab.

This is what it looks like:


If you need to modify the scale, you do that in Sketchup.


And definitely install TT_Lib2! It's like a pre-plugin to install the Solid Inspector plugin, which is, like said, one of the best plugins for 3d printing with Sketchup.

- multihawk

Not a dumb question at all!

There are a couple of reasons behind the 1:1000 scale I use in Sketchup.

The first reason is hard to describe... I was going to say something about SU accuracy at small scale... it's nothing really to do with that. I believe the original reason was something to do with simply displaying the model at tiny scales.

As an example - I work at 0.1mm resolution, not much point going beyond that as the SW SLS printers have similar constraints on resolution. Now if I'm doing complicated geometry, say some curved (faceted) surfaces intersecting with other curved surfaces I usually want to erase all extraneous geometry so that my model is 'watertight' or manifold. I use the Solid Inspector plugin to check for anomalies and sometimes these show up as tiny polygons or lines. If my model is zoomed so that the entire screen is showing only 1mm of my model, and Solids Inspector is showing the anomaly as a 'speck' then to 'see' the problem and deal with it I need to zoom in even further, often beyond the abilities of the software to resolve and display the model. Result? Blank screen and no way to erase the problem geometry.

Go to 1000x scale and the same anomalies show up - but this time the line or polygon might be just 1mm on SU which is well within the capabilities of the software (but in reality a microscopic 1/1000th of a mm!). I can then see and deal with the erroneous geometry.

I hope that description makes sense!

The other reason is that when scaled this way the Shapeways uploader somehow 'gets' you're using enormo-scale and scales the model back to its real world size. This kind of makes sense, as the printers can't print 10 metre long objects!

Granted, I'm not sure how this works in inches - could be a 1000x1000x1000 inch model in Sketchup is resolved by the uploader as 1x1x1 inch... this is something for you to try at home . As multihawk points out, the uploader is flexible on units of measure.

Good luck!


Steven

I'm pretty sure if the combination of model file you're using and upload units (assuming the file type requires/allows them) doesn't make sense then the Upload Process will try different units to scale up or down until the Model fits. And I would guess that it will try unirts in the order mm-->inches-->meters.

If it does this you will get a message in the Edit Details Screen for the Model under the History Tab of the Model Tab (not my design!).