Every now and then a little gem of usefulness appears on our forum that is just too good to leave it just there. Community member Jeff LaMarche wrote a great tutorial on getting your Blender designs cleaned up and ready to upload to Shapeways. Together with Jeff, I cleaned it up a little and republished it as a full-fledged Shapeways tutorial. Thanks, Jeff!
This post is meant to give you guys a better indication of what is and what is not possible with 3D printing Stainless Steel. These guidelines are based on all your uploads and are a work in progress. They are meant to be indicative. We have images to illustrate these examples and I will add them once we have permission from the model owners.
I know that mass and weight are weird things to consider when 3D
modeling(unless you're a CAD person of course). But, look at your model
and think, if I made this out of clay would it work? This is really the best tip I can give you.
small parts up to 50 by 50mm
95% of these parts print successfully. They can have very thin walls of below 3 mm. But, the most important reason for failing is that the parts are not strong enough or do not self-support. The model will either fall apart or crush itself. Lets imagine we are trying to print a wine glass standing upright. A 3 mm thick stem might work if it were printed alone. But in a wine glass the stem has to support the bowl. During production the model is very fragile. If the bowl is heavy it will simply topple over.
Lets imagine now that we are trying to print this same wineglass horizontally. The stem would break in the middle. Lets now imagine that we are trying to print a wine glass that has no stem but simply consists of the bowl. This would work because a wine glass bowl is a self supporting structure without a weak point that could cause the model to break. What if we get ambitious and would like to add lots of decoration to our wineglass bowl? This is possible. But, if the decoration would consist of a lot of mass the weight would break the bowl during the printing process.
With Stainless Steel it is not a case of absolute wall thickness as with the other materials. The EOS printer that makes White, Strong & Flexible simply can not print thinner walls than 0.7mm (really, please only use 1mm or higher). With Stainless Steel there are a lot of variables. This is why it is so hard for us to give you guidance on what can and can not be done.
Very thin or delicate structures can not be printed either. If it looks wispy and lovely and feather-like it will probably have an issue. People have to remove support material, put it in an oven etc.
Integrated 'whole' parts have the highest chance of success. Lets imagine you wanted to print a plate of spaghetti. If it was one mass of spaghetti on a plate it might be possible. If there were strands of spaghetti that magically would stand upright and horizontally in all directions it would not work, it would break. If it would be and incredibly thin structure consisting of many individual strands in a bowl, it would not work. It could simply not be cleaned.
Furthermore since there is an oven step involved whereby the models are all heated to a high temperature parts might fuse if they are loose or close together. So, a bowl of many individual strands of spaghetti would fuse.
Medium to large parts less than 200 by 200 by 100mm
These parts need wall thicknesses of 3mm. Why? The part is larger so the internal structures supporting the part need to be stronger.
These are what I can give you right now. I hope to get more information to you as we learn.
We ultimately want the Shapeways upload filters to be perfect. We'd like us to be able to repair any file automatically. And even though each day brings us one step closer to that goal, we are not there yet. Specifically to help you guys out with your wall thickness issues we went on the hunt for a software tool that you could download right now. We hoped that the right tool would make life a lot easier for you guys. After months of looking and two weeks of testing by five of us, we've found one. It is called Netfabb Studio Basic and it rocks.
Previously we helped you guys by showing you Meshlab, a free and open source tool that is great for polycount reduction, mesh resurfacing, normals recalculation, viewing issues with models for 3D printing and converting. We also have shown you Accutrans, a free for 30 days, tool that is great for converting from lots of different file types and scaling. In addition to these tools there is a great closed source commercial package out there called Magics by Materialise, a 3D printing service bureau. This tool even goes as far as to automatically repair your STL files in some cases. It is a great tool, the only problem with it is that it costs $7000. Materialize even has a service called STLFix where you can repair your STLs. There is a free version of Magics called mini-Magics. But this is only an STL viewer and doesn't let you repair anything. There is also 3D scanner software such as Polyworks and GeoMagic that are meant specifically for repairing meshes made from scans. These are also good but as Magics, they are also expensive.
There really was no commercial alternative to Magics, until now. Netfabb Studio views STLs, repairs STL files automatically, scales them, inverts normals, measures STLs and lots more. This tool blew me away. The second best thing about it is that Netfabb currently costs $399. The best thing about Netfabb? There is a free version of it that you can download. This does a lot of the things the commercial version.
With the free version of Netfabb Studio Basic you can:
automatically close holes
automatically invert face normals (inverted or flipped triangles)
automatically repair non-manifold errors
easily measure the wall thickness of STL files
easily measure dimension and volume of your model
easily scale STL files
manually remove, invert and add faces triangles and shells
One huge word of caution before you collapse from joy. Even though Netfabb is a great free tool it can not solve all your problems. A lot of files can simply not be automatically repaired. The free version also does not remove intersecting triangles. The software can not repair with 'degraded triangles.' You can select and remove some shells but the free version does not have a way to automatically reduce many shells to one. So this will not make all your STL problems magically go away. We've been testing it for two weeks and we're impressed but realize that no software tool can fix everything automatically. It is a huge step forward though.
Read on to see how to use and what you can do with the Netfabb Studio Basic STL viewer and repair tool.