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Difficulty: Advanced
Objective: When asked, what is the maximum angle I can print? The answer is - It depends.


From all my experience printing objects I have thought up what I call the wiggle theorem. It is an essential idea to know in 3D printing.


Here in Moscow, it is extremely common for women to wear high heels. And one of my pet peeves is when women wear high heels and can't walk normal. Here in Moscow, its likely can run on ice in heels, but in America i see women wobbling all over the place just by walking on a sidewalk and it drives me crazy.

When it comes to 3D printing you don't want your model to be wobble, you want them to be like a Russian in heels. Imagine trying to draw a picture in a rough car ride. Similarly a printer struggles to print on a moving, wobbly surface.


How to make it not wobble?

Back to the example of the high heels, you have some factors that make up the heel.

Diameter - if the heel is super skinny it will be harder to balance on.

Height - a small heel with a tiny diameter may be easier to balance that a really tall heel.

Angle- if your heel was angled its going to be harder.

The combination of these go into what I call the wiggle theorem. The reason it is important is because it answers questions like: What is the maximum angle before I need supports?





The typical answer to that question is 45 degrees. Others may say something like 60 degrees. But I have seen things print practically horizontally at like 90 degrees perfect. And I have seen things print at a small angle and fail. An that is why I came up with the wiggle theorem. It's not necessarily the angle but a mixture of things found in the wiggle theorem.

This becomes especially important in creating custom supports. A common mistake is to make a tall thin support so it breaks off easily. However even though it is printed vertically so and angle of 0, eventually the height will reach a point where it starts to wiggle and the printer misses the support.

Experience is Key

Because every printer is different the results will greatly vary on what your printer is capable of and how much it will violate the wiggle theorem. A wise idea would be to test the limits of your printer. Many of these test can be found online such as:

In Conclusion

You want your model to remain stable and not wiggle at all while printing. Models fail when they become too thin, too tall, and have too much of an angle.





Please leave your comments.

and as always thanks for visiting,
The 3D Printing Ninja

3DNinjaneer@gmail.com



Difficulty: Intermediate
Objective: Know why you should learn to animate. To know how to animate see the video tutorials on Animating

Most people think that animation and 3D printing are two different subjects. But if you want to make an object with a more realistic effect or make a model look like it was taken mid action, animation is definitely for you. The good news is that the modeling is the hard and boring part, and animation is usually just a few more steps.

Realistic Looking

Imaging modeling something such as a curtain or a cape for a a superhero. It would not only take a long time to model, but probably will take a very long time to make it look real. With animation, you can simple let physics take over and model the cape to imitate real life.

Here is what I printed for my Wacom pen holder.


As stated earlier this can be model much faster with physics and animation, than only modeling.

There are many options as collisions, fluids, smoke, and as seen below melting.


If you are into a more artistic style of 3D printing, then you can create some amazing pieces. And currently I see very few people taking advantage of this. It's a great opportunity in my opinion.

Mid-Action Shots

Imagine watching a movie and then pausing it at any time to 3D print that scene. This is basically what happens when you animate a model. You can pause the animation to capture a specific moment that you would like to print. 

To animate a character you typically add in bones (rigging) that make a system of how the model will move. Once that is done your model is like a doll and you can move it in all sorts of positions. So if you wanted to use the same object more than once, this can give it a lot of expression.


Please leave your comments.

and as always thanks for visiting,
The 3D Printing Ninja

3DNinjaneer@gmail.com




Difficulty: Intermediate
Objective: Learn about an excellent add-on to check your models in Blender for 3D printing. The most important check is to make sure your model does not have non-manifold geometry.

3D Printing Toolbox

  1. Install the add-on in Blender called "Mesh: 3D Print Toolbox" by checking the box and then Save user settings.
  2. Be in edit mode of the object. 
  3. On the left hand side window, [T], expand Print3D section.
  4. Input the settings of your printer's capabilities in the Checks section and then push check all.
Scroll down and choose what you want to check. For example I checked where the overhangs are. Now I know where I would need supports.
For 3D Printing the most important checks are:
  • Non-Manifold Edge (Holes)
  • Intersecting Faces
  • Thickness 
These should all say 0 next to them. The other checks such as zero faces, zero edges, thin faces, sharp edges, etc. are not really that important.


    Another Method of checking your model:


    1. Go in Edit Mode
    2. Open up your Properties Window [N]
    3. Check Mesh Analysis and choose the check
    The faces that are colored are the faces that fail the check. The closer the color is to Red, the more of a problem it is. And the more the color is to blue, the less of a problem it is.

    Once again the important checks for 3D printing are:

    • Intersect(ing Faces)
    • Thickness


    Please leave your comments.

    and as always thanks for visiting,
    The 3D Printing Ninja

    3DNinjaneer@gmail.com







    Difficulty: Advanced
    Objective: Learn how to add supports and by which method. 



    What are Supports?

    When I was in China I worked on site of constructing a manufacturing facility. In the picture above you can see the scaffling that we used to build it. (It was really scary as the thin bamboo would bend as you walked on it!) Scaffling is similar to supports, both are removed after the construction is complete, and necessary to construct it. 

    For those of you who do not have PVA filament capability on your printer, this is an essential blog for you. Supports are extra plastic that are printed for stabilizing and for areas where the printer would otherwise print on air. After printing the supports are broken off. This sounds easy enough but it is the hardest aspect of 3D printing. And unfortunately I have not yet come across a software that has a user interface that makes it easy to add supports and adds good supports. 

    How do I Add Supports?




    (Methods of Adding Supports from best to worst)

    1) Just don't. If you can design your model so that no supports are needed, then this is ideal. But this is often not possible. Therefore see if you can orient your object in a way that uses the least amount of supports. 

    2) Custom supports added as part of the model. Sounds easy, but requires the user to know where supports need to be added, how to add them, and how to make the supports. Overall it is an advanced method. But is the method I use and recommend. 

    3) Autodesk Meshmixer. Is for people who are willing to put the effort in one step ahead of using the printers settings for supports but not enough effort to make the supports themself. It is a way to add supports automatically much better than your printer will. 

    4) Default automatic supports on the printer's settings. Easiest method as you simply click yes to supports, but expect to spend the rest of your day trying to get those supports off. You'll break your model in half, slice your finger open trying to cut the support off. It aint fun. 

    There are usually advanced settings where you can adjust the settings of the automatic supports, but by this point you might as well use any of the methods above this. 

    Why are Supports So Difficult

    1.) You have to know where to add supports and how dense to add them
    2.) If you rescale your model size for printing it will also rescale the supports making them too small or large. Causing them to be too thin to print properly or too big to break off.
    3.) When the model is sliced supports often confuse the slicer making strange codes for the printer. 
    4.) When breaking off supports you can easy break the part of the model off along with the support. Especially with small details. 
    5.) Since you are breaking off the support it will be noticeable. It will take after maching such as sanding to hide the rough spot where the support was broken. 
    6.) If you have a really complex model, the time need to add and take off supports can be a long time. 

    Feasible Designs of Supports

    There are a few designs listed below that I have found useful. Lets say we want to print this cute little dragon:


    The Beam

    You can use a circle, square, triangle, I-beam, or whatever cross section. (I will mention that 3d printer that I use at work slightly struggles with circles so I like square cross sections). 




    The Thin Plane

    Theses are easy and work well as long as they don't exceed a certain height. Once they become too tall they wobble too much and are not stable. However you can always taper the plane so that only the tip is thin.


    The Ring

    This is a mix of the beam and thin plane. This design is great because when you squeeze the cylinder it pops right off. I used it to print a goblet and it worked beautifully. The cylinders are not solid, they are thin as if you took the thin plan above and rolled the ends together.



    The Tree

    This is what Autodesk Meshmixer uses and is good because it doesn't waste as much material. Like the beam method except that it branches out both towards the object and the bed plate. This can be combined with any of the above, for example making a thin plane with holes in it, like a bridge truss. Perhaps this is the best method by optimization, but can be yer most time intensive. 


    When do you not need supports?

    First of all anything that is horizontal will not need supports. I have seen printers bridge 6 inch gaps with just a little error. However to be on the safe side I would bridge no longer than an inch. Under such a bridge no supports would be needed. Please note that the bottom layer of the bridge must be horizontal and not slanted or arched.




    Please leave a comment.
    And as always, thanks for visiting.
    3D Printing Ninja
    3DNinjaneer@gmail.com






    Difficulty: Intermediate


    Overview: If are trying to edit a model made in a CAD program (CAD in the sense of being an engineering 3D modeling software) in another program such as Blender and have found that the model has horrible topology, this post is for you.


    What is an .stl?



    3D printing can take a file in a few formats, the most common format being an .stl. This is the typical format that all programs will export a file as in order to be 3D printed. Imagine it like a .pdf format. A file that everyone can access, but is a pain in the butt to edit and modify. If you designed your file with good topology then you won’t have a problem. If you don’t know what good topology is then you most likely used a CAD program. And there are two reasons why I hate when CAD programs export a file as an .stl.

    Problems With CAD to STL Conversion

    The conversion is almost always horrible. The geometry is often crazy and the model is changed in the conversion. For example a smooth edge gets changed so that multiple edges make a smooth edge.

    If you wanted a smooth edge you will have to manually correct the conversion by adding more geometry. Furthermore the conversion creates a non-uniform mesh. One face of the mesh might be 1000 times larger than another face. Triangles, squares, and polygons appear. The non-uniform geometry makes it almost impossible to edit and deform.

    Basically it looks something like this. This is bad because the geometry is not uniform.

    How to make a better stl conversion? (Via Blender )

    Basically our goals in doing this are:

    • Make the geometry uniform
    • Keep our geometry count low
    • Keep the original Shape (note that the shape may slightly alter)
    As you can see there is little changes to the cars below. We want to find a point where our geometry is low, but we still have a good shape. And as


    1.) Remesh Modifier

    This is probably the easiest for people with little blender experience, however it often creates an excessive amount of faces. If you are wanting to add something with fine detail such as a texture the excessive geometry will most likely be needed. This can be done with the DEFORM MODIFIER. The following are the most important aspect of the tool.

    Sharp / Smooth / Blocks

    If the model has a sharp edge use sharp. If it doesn’t then use smooth. Or if you want like an 8-bit looking thing use blocks.

    Octree

    This is similar to subdivide, the higher the number the better the result, but the slower the program will run.

    Then you will get something better like this. This has more uniform geometry but perhaps overkill. If your computer can handle this, then it is okay to stop here. Otherwise see the next steps.

    2.) Decimate or MeshLab

    If your model is simple enough you can use blender's decimate modifier to reduce the geometry. and get something like this. Which is far from ideal, however somewhat better that when we started. 

    However the better option is to export your remeshed model into a program called Meshlab that can handle the decimation better. Under Flilters -->Meshing, Simplification, and Reconstruction you can apply filters such as Surface Reconstruction Poisson, Quadratic Edge Collapse, Uniform mesh resampling, tri to quad, etc. until you are happy with your results. And you will get something like this:

    From here you can work easily with your model. Not that the model will change

    OR...

    Manually

    Depending on how bad the conversion is and what you want to modify you may be able to simply change the model by rearranging the geometry and using the KNIFE TOOL to add more geometry. Depending on the situation this can be the easiest method as the other methods often may not work without a lot of geometry.

    However there is a more time consuming way called Retopology. Here is a good video on how to do this:

    http://www.youtube.com/watch?v=icqPZnD_3lA

    Shrink Wrap Modifier

    This tool takes the geometry of one mesh and then places it in the for of the second mesh. This method is fairly simply however it seems to work on simple shapes and not well on more complex shapes.

    Can you convert from an stl to a CAD format?

    Now if you try to go the other way, from an .stl to a CAD format such as an .iges, it is impossible. I have searched a great many hours for a program that can convert an .stl into a format that can be used in a CAD program and all I have found is dead ends. If you find something that can and you have personally done it, please inform me.

    The reason why you would want to do this is because most files downloaded from the internet are in stl format. If I wanted to add something of a specific size such as screw holes, it would be easiest in a CAD program. A person could then take any model and easily design it.

    Please leave a comment.
    And as always, thanks for visiting
    3D Printing Ninja
    3DNinjaneer@gmail.com




    Difficulty: Noob

    Objective: This post is for those of you who have just started 3D Printing and Computer modeling. There are a few things that I have found absolutely essential to know and would be what I would want to know if I was just starting. Search this blog to find a more in depth post about a certain topic...

    To learn how to use Blender see this post: Blender Curriculum: Video Tutorials

    1.) Topology


    When you design a model for 3D printing, (especially Blender) there a thing called topology which is the geometry that makes the model. If you are like me, at first you won't care about the topology, but eventually you will realize that good topology makes your life so much easier in the long run. Bad topology greatly limits the ability to modify the model, increases the risk of non-manifold problems, and just doesn't look pretty. Just remeber this: If you start with bad topology it's a snowball effect where one little problem becomes thousands quickly. So take your time at the beginning because good topology stays better, bad gets worse.  Good topology takes practice to get into good habits while modeling. The following are some of those good habits. 

    Uniform Geometry


    Think of the size and amount of the faces that make up the model as high definition. If you want your model to look like an 8-bit video game then use large and few faces. But if you want your model to look 1080p high def then you will need lots of faces that are small. As a rule of thumb all of your faces should look similar to each other in size and shape. The main exception is if certain areas of your model have more detail. For example if you were modeling an arm, the knuckles you need more faces than the rest of the model in order to get the detail of the wrinkles. 

    The sphere above for example, has bad uniform geometry. Notice how the faces near the equator are compared to those at the poles. They go from squares to rectangles to triangles. This is why I almost never start with a sphere, but rather use a cube and evolve the cube to a sphere by subdividing it.

    Subdivide


    Only subdivide the geometry when you have no other choice. Subdividing is a way that makes 1 face become 4 faces giving the model more geometry to work with and making better detail. Life would be great if you could subdivide a million times, however the computer can't process that. When you start it will be tempting to simply subdivide the model to acheive what you want. But you will run into a dead end when your computer can't handle it. Therefore if you can make good topology, then you won't need to subdivide the model as much and your computer will love you and you won't be yelling at your computer. It's very easy to go from low definition to high. To see this in action subdivide the square or Suzanne the monkey, to see how easy it is to get better definition. So don't worry if your model looks too blocky it will smooth out in a blink of an eye. Definitely learn to use the multistage tool.  

    Triangles, Squares, or Polygons?


    Your geometry can be composed of many shapes, the best is geometry made of all squares. The reason is because squares make editing a model easy. For example you can add or deleted an edge loop like a boss. Other shapes won't. The other common way is to use triangles which is mostly used in video games because less geometry is needed speeding up the processing of the game. But for 3D printing we aren't concerned about how many faces there are, as long as we can model it. Also if you cut a square diagonally in half it becomes two triangles, so if you have to convert it, it is easy. I almost always start my model from a square and almost always only use square faces. 

    Non-manifolds


    There is usually a tool to find non-manifolds on a model, which are problems the printer has with the model. When you design, often check the model for non manifolds. On Blender this can easily be done in edit mode--}select non-manifolds or hotkey (shift+alt+ctrl+M). A simple way to accidentally create a non-manifold is to duplicate geometry. This can be done by extruding geometry but not actual translating it to a new location. Even more so often when you undo an action make sure you undo enough times. Very often the non-manifolds I find in my models are due not pushing undo enough. 

    To learn more about non-manifolds see this post: Non-manifolds: Your Worst 3D Printing Nightmare

    Overhangs

    Because many 3D printers cannot print mid-air there is a limit to how steep an object can be before it will not print. If you object exceeds this limit then it will need supports. Supports can be messy, so ideally you want to orient and design your model to use no or as few supports as possible.

    Please leave your comments.

    and as always thanks for visiting,
    The 3D Printing Ninja
    3DNinjaneer@gmail.com





    Difficulty: Noob

    Objective: If you are just starting to use Blender, menus such as this one probably seem quite intimidating. If I were you I would just ignore most all of these for now. And the modifiers that you should focus on learning are these:



    To learn Blender see this post: Blender Curriculum: Tutorial Videos

    Multiresolution/Subdivide Surface


    First of all I don't know why there is a Subdivide Surface modifier when it does the same thing that the Multiresolution modifier does. But I listed it anyways however I would just always use the Multiresolution modifier, In fact, I don't know if I can recall a time I was using blender and didn't use this modifier.  It's a beautiful feature that allows you to do to different levels of subdivisions. Even more so it gives you options of what level to subdivide in the display (Preview) in sculpting (Sculpt). I don't apply this modifier until the nearly the end (as you should for many modifiers) and its powerful to be able to constantly switch levels of subdivisions to work with. So for a square 

    Array



    Think of an array as copy and pasting your object, only with control of how many times to paste and where to paste. Any scene with repeated elements such as a fence or leaves on a plant are perfect to use an array on. 

    Mirror


    One part of art that makes things look beautiful is symmetry. With computer modeling you can mirror your object to make it perfectly symmetrical.  Not only does this look great but it also saves you half the time because you only have to do one side. Keep in mind that you can mirror over any line, so you can make complex patterns easily. 

    Curve


    Let's say that you have a straight road that you want to go on a hill. With the curve modifier you can command a 3d object to move onto a curve. 

    Displace


    If you want to put a texture on a model this is the modifier to use. First you will have to subdivide your model into really small faces to get the detail. So this should probably always be the last modifier to use. Then you can add an image that will repeat itself to texturizing your object. It can be really neat. I texturized my phone case i 3D printed to give it more grip because smooth PLA is quite slick. 

    Remesh


    This is a great way to import a CAD model and then add a texture as mentioned above. Remesh modifier takes your model and tries to redo the geometry, to retopologize it. Most likely it will not be the best geometry and it's better to manually retopologize, but it can be useful if you just want to do something like texturize it.

    See this post for more details: Remesh Tool

    Boolean


    Think of this modifier as a way to join 2 objects together. You can combine them, intersect them so only what intersects remains, or cut out of one object where they intersect. Although I will warn you that this leave really funky bad geometry that may need work. But overall this is a very easy way to combine to objects.

    See this post for more detail: Boolean Trouble

    Please leave your comments.

    and as always thanks for visiting,
    The 3D Printing Ninja
    3DNinjaneer@gmail.com



    Objective: Understand what you will need to 3D Print and that most all of it is free!

    Ready to use 3D design software to design your own stuff!


    My greatest fear about 3D printing is that too few people will put in the little effort to design their own models. Please don't just be someone who only takes other's designs. You can design great things! And you can design them completely free.



    Free 3D Design Software

    Blender 


    This software should be the Eighth Wonder of the World. It is a beast as it is available on Mac, Windows, and Linux and is more like 5 software programs into one. I will admit that it is quite intimidating to start, but there is a great amount of help to learn the software as linked below:

    To Learn Blender see these tutorials
    Not to mention many others on youtube and other sites. You can also ask me if you have questions.

    After using this software, I don't know why someone would pay for other programs who isn't doing this professionally. There are also many add-ons to do additional tasks. Most all of my blogs with be based off of Blender.


    You can download Blender here





    Autodesk


    This is favorite company behind various software. As an engineer I prefer to use their software over others for ease and capability. For students you can download an education version for free. I would highly recommend looking into programs such as Maya, Inventor, and Mudbox. 

     Here is a free simplified version called 123D Design: http://www.123dapp.com/design

    Here is another software useful for automatic supports: http://www.123dapp.com/meshmixer

    Here is the link for students: http://www.autodesk.com/education/free-software/all




    Gimp


    This is a free alternative to photoshop. Image editing software isn't need for beginners but definitely useful for advanced users. 

    Here is the link: http://www.gimp.org/downloads/





    Crazy Bump


    This program takes an image and then converts that image to several other types of images used in 3D modeling. It alows you to tweak the settings and in my opinion essential if you want to make your model look real on a computer. 

    Here is the link: http://www.crazybump.com






    3D Design Commercial Software


    Catia, Solidwork, Pro-E, NX, etc.


    These programs are expensive and in my opinion not worth buying. These programs are typically used by engineers and are great for making parts that need specific tolerances and dimensions.  Catia is a beast, but not necessary for 3d Printing.




    Zbrush, Cinema 4D, etc


    These are what animators and artist use, however the price once again I think is not worth it. 






    Photoshop, Illustrator


    If you are going to design anything on a computer, Adobe's products are a great software to have. If you plan on designing more than only 3D printing, then I would look into these programs. They come in handy for many tasks. 




    3D Scanning and Apps


    Autodesk 123D Catch


    Now this is one of the coolest apps in my opinion. It allows you to take several pictures and then sen them to a computer that arranges those images to make a 3D model. It definitely is far from perfect and the lighting and set up can make the end result vary. 


    The reason I think it is such an awesome app is because i think it's the start of somethin bigger. You could take a few pictures of your key and then print it. You could take a picture of something that is broken and then make a perfect fit model from it. Or you could be a spy an take a few pictures of someone's face and then print out a replica face. 

    Or you could, "teleport" by taking picture of an item and then printing it out at another location...

    Download it from your app store or here: http://www.123dapp.com/catch



    Augment


    This is a cool way to show off your model where you can place a model seen through your camera. You can place your model on a business card, blueprint, or almost anywhere. It's sure to impress. 

    Click here for more information: http://augmentedev.com





    Programs to Avoid & Software Errors

    Google Sketch

    I do not know if I have ever seen a file from google sketch print properly. It is almost certain disaster when it comes to 3D Printing. Perhaps one day they will fix their software to 3D print better but until then avoid it for 3D Printing.

    Solidworks

    There is something not quite right about using a shell tool on a model in solid works and then 3D printing it. It doesn't happen all the time, but I run into it frequent enough at work to know their is a problem with Solidwork's shell tool.





    Other Items to Mention

    Tablet


    Depending on how artistic your work will be you may want to look into buying a tablet. A mouse will always work as I would strongly advise against using a trackpad, but a tablet can make a huge difference and speed up the process of design. It would be like coloring with a marker or a colored pencil. A drawing tablet gives you control over how hard you would like the mouse to click. If you plan on sculpting and doing a lot more artistically desigb I would highly recommend a tablet. Don't be fooled into buying anything expensive, just get a cheap one. 



    Please leave your comments.

    and as always thanks for visiting,
    The 3D Printing Ninja
    3DNinjaneer@gmail.com