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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



Objective: Learn the capabilities of Autodesk's Meshmixer & why I recommend this software.

Download this program : Autodesk Meshmixer


What is Autodesk's Meshmixer?

This is a great program not for modeling, nor for slicing the model, but for the in-between stage. I personally use it to quickly fix non-manifolds, remesh, and most often to generate supports.

Advantages:

  • It's Autodesk, they are by far my favorite company to make software. I think they are the software for the future as well...
  • Free
  • Awesome adding supports feature
  • Non-manifold fixer
  • Remesh, patterns, primitives, and many other features.
  • Works on Mac & Windows

Disadvantages:

  • Sculpting is not good
  • Processing is sometimes slow and crashes

Where can I Learn how to use it?

 

 

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: Noob
    Objective: If you have never used Blender before and want to know where to start learning how to, this video was made just for you. It was inspired by Tunapanda, whom I will give a shout-out to, and you can find more information about them here: http://www.tunapanda.org.

      Noob

      These are the video tutorials to learn blender (in recommended order). If there is no link, then that means the video will be uploaded in the near future.


      Intro, Dive In:

      Object Mode:

      Edit Mode:

      1. Selection
      2. Scale, Rotate, and Move
      3. Proportional Editing
      4. Extrude, Delete vs. Dissolve, Merge, & Fill
      5. Join, Separate, and Split Parts (Knife Tool)
      6. Edge Loop
      7. Mirror
      8. 3D Printing Checks
      9. Creating an arm
      10. Curve Modifiers
      11. Grid Fill

      Sculpt Mode:

      1. Brushes
      2. Symmetry
      3. Background Image

      3D Printing:

      1. 3D Printing Tool-box
      2. Measuring

      Rendering:

      1. Camera
      2. Lighting
      3. Materials
      4. Textures
      5. Compositor

      Animation:

      1. Simple Animation
      2. Rigging
      3. Collisions
      4. Cloth
      5. Liquid
      6. Smoke

      Intermediate

      1. Retopologize
      2. Curves
      3. Arrays

      Advanced

      1. To be Announced

      Additional Materials

      You can download the curriculum and hotkeys for Blender online here: 

      Other Useful Tutorials


      Please leave your comments.

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

      3DNinjaneer@gmail.com




      Difficulty: Intermediate
      Objective: Use the software, Autodesk Meshmixer, to automatically apply better supports for printing. 


      What are Supports?

      Supports are extra printed material that are separated from the model after printing. Their purpose is to keep the model stable and give the printer something to print on since a printer can't print on air. Supports are what makes a 3D printing affordable and what will drive you mad. Being able to do good supports is the most valued skill in consumer 3D printing in my opinion.

      For more information on supports see this post:
       http://3dprintingninja.blogspot.com/2014/10/supports.html

      Steps Before Adding the Supports:

      1. Create your model, check for non-manifolds (this can be done in Autodesk Meshmixer- >Analysis-->Inspector). See: http://3dprintingninja.blogspot.com/2014/07/non-manifolds-your-worst-nightmare.html
      2. Scale and Orient your object (Autodesk Meshmixer-->Edit-->Transform). If possible it would be wise to import your model already properly scaled into Meshmixer. Otherwise the supports will be disproportional to your model upon adding them.

      Supports via Meshmixer?


        See image above for the following steps:
        1.  Autodesk Meshmixer-->Analysis-->Overhangs)
        2. Select your printer - This will default many of the values for you
        3. This determines where to put the support. 45 is a normal value, I would not suggest going over 60
        4. This is how easy the support will be to break off the model. I recommend .4mm. The smaller the value the easier it will be to break off, but also the less likely it will print correctly.
        5. This is basically how many supports
        6. This is how thick the support will be. This depends on how high your support is. The higher or more angled a support the bigger thickness required. See the post on the Wiggle Theorem...
        7. This is what will be printed onto the bed for the support. I think the bigger the better on this option if material cost isn't an issue.
        8. There are controls which I skipped because they aren't that important. To learn more about them follow this link: https://www.youtube.com/watch?v=aFTyTV3wwsE  Otherwise push generate support.
        9. If you are happy with it then push convert to a solid.
        10. Export your file to be printed. (Both steps 9 and 10 can take a long, long time. It may appear as if the program is frozen. I recommend minimizing the window and working on something else or taking a break and come back to it)
        11. If you are not happy then you can push remove support, and repeat the above steps by tweaking the settings.

        Most Likely at Step 8,

        You will find that the supports generated are not quite right. Luckily, Meshmixer allows you to add and delete your choice of supports. I rarely do not delete and add a few of my own supports to the model.
        • To add a support, click and drag the mouse. I recommend starting in a blue are or at a previous support. While adding the support you will notice that the color of the support will change from green to yellow to red. Green is go, stay in the green. Otherwise if it is red it probably won't print.
        • To delete a support, ctrl+click
        • You can also have multiple sizes of supports. For example you can start by adding a thicker supports. And then redo the process but with smaller supports


        Conclusion

        Although this process may seem difficult, it will save you frustration of taking off the supports. It is not a perfect method, however it is constantly improving and in my opinion the best method of adding supports without fully customizing each support yourself.

        When Adding Supports...

        1. Make sure that there is open space between the model and the support, otherwise your model will fuse with the support. It is not a huge deal, only that you will need to cut off the support.
        2. If you make the supports too small it will jam the printer, depending on the printer.

        Examples of the need to use Meshmixer

        This was a Cathedral that was being printed by floors. As you can seen the 2nd floor failed to print as the angle at the tops of the window was too steep to print. Therefore supports need to be added. If this was done with the printer's automatic supports, it would be a mess of supports. With Meshmixer, you can nicely add a few supports.


        Let me know your thoughts:

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










        Difficulty: Noob

        Objective: Learn the very basic 3D printing tricks

        1.) Painter's Tape on Print Bed


        If you find that you are having a hard time getting your 3D prints off the bedplate, or if you are having a hard time getting your print to stay on the bed plate. Then try putting on Painter's tape. I recommend that you choose the thickest painters tape as the line between the tape will show up on the printed object. I also recommend pulling the tape not only on the top of the bed plate, but around the edge and even on to the bottom.

        You can also use pins to pop the air bubbles that form while printing and taking objects off the bed plate to smooth it out.

        2.) Printer Settings

        Supports


        Ideally I make all my own supports so I set the automatic supports setting to off. However id it is on then you can change the angle which is where the supports will be automatically added. The following are where rafts would be needed. 

        Raft


        Rafts help stabilize and keep a model flat from warping. Rafts are extra plastic that comes off the model. The following are examples of when it may be good to or not to use a raft. 

        Material

        Each material melts at a different temperature, therefore you need to set the printer to the right temperature. Also make sure that you have enough material to be printed. Most 3D printers will continue without material. So if you have a large object to be printed and the material runs out the printer continues leavin you with an unfinished object with no way to continue it. 

        Custom settings


        These are often over looked when they are quite powerful. Often these include things such as shells, speed, infill, etc. It would definitely be worth looking into and figuring out what each setting does. Changing a setting can often fix a print. 


        3.) G-code


        It sucks to print something for 8 hours to come and find a mess. This can be avoided by checking your model before sending it to the printer. There are many ways such as checking for non-manifolds on the software you used to make the model, using additional software such as Autodesk Meahmixer to find non-manifolds, but the best is to look at the G-code. This can be done at ws.gcode.com where you can upload your model and look at how it will print later by layer. 




        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: 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