Digital Jewelry Design: a Fashionable Introduction to Inventor

A decent majority of people on this planet have, at one point or another, entered a jeweler's in pursuit of some sort of accessory, be it for ourselves, or that special someone. Though retailers often have a wide selection of designs, there are times when what is available just doesn't seem to fit the bill. In these instances one can explore either of two main options to obtain a custom piece which meets the desired specifications:
            
            1. Enlist the services of a private jeweler.            
             2. Make it yourself.

This Instructable explores an avenue of the "Make it yourself" option, by exhibiting the use of Autodesk Inventor to design and create a custom piece of Jewelry. The intended result is to help familiarize users with some basic concepts of the application, while offering an opportunity to create an unique, artful product. 

*For more detailed help with Inventor either use the programs built in tutorials, or visit
Autodesk's website
       http://usa.autodesk.com/

ALSO if you like this Tutorial please vote for it in the MakerBot Challenge

For those who aren't familiar with it already, Inventor is a 3D CAD program (sometimes referred to as a parametric modeling program) that implements powerful mathematical operations to render objects in virtual space. Part designers, engineers, and draftsmen can take advantage of the multitude of tools within the software, many of which emulate machining operations, to model a part without ever touching materials, or equipment other than a computer. This is extremely beneficial to companies in that it saves on material costs, machine time, and training cost, as only a single person, or small team, versed in the program, is required to craft the digital representation of a piece. Additionally, if a mistake is made there isn't any need to scrap the entire project simply undo the error and continue working.

Once parts are created they can be placed into an "assembly" environment which, as the name implies, allows for parts to be assembled as they would in real life. Assemblies can range from the size of a building (with details down to individual fasteners though this would require massive processing power and amazing graphics card) to something the size of a mechanical pencil.
These builds can then have simulations run on them to provide critical information on part interaction, stress loading distributions, etc. which are helpful in determining what materials should be used in the final product, or whether part designs need to be further optimized.

As a design is finalized it can be converted directly into blueprints without the use of another program. Another option is to send parts to a 3D printing service, so that models can be showcased and scrutinized, before true production begins.

Sadly, Inventor is not an open source product, and is quite pricey. Though free student versions are available, proof of attendance to an education establishment is required. As a result  the general public cannot usually afford to own a private license to the software.  

The user interface is the conduit through which a user communicates to the Inventor program. The release of Inventor 2011 debuted an entirely new system referred to as Ribbons. This method provides a logical and customizable method of accessing basic windows and commands by placing them into sets which will change to reflect the working environment. Commands which in previous releases have had their own toolbars can now be found in tabs (categories) along the ribbon. For example commands which used to be found on the Model Feature Toolbar are now present on the Model tab. Tools located in tabs are further split into common "Panel" subcategories which makes locating specific tool types even more simple and efficient.

The ribbon is just one of the major areas found on the application screen, since it is important to know your way around before you start modeling, lets get an overview on the new User Interface.

Below is a basic breakdown of the major areas on the screen. (visual representations can be found in the pictures of this step)
    1.Inventor Application Menu- contains commands for working with files (functions similar to [File]
         on most other programs)
    2.Quick Access Toolbar- Accesses common commands (i.e. save, open, and new) and commands
         that can be added or removed.
    3.Information Toolbar- Displays help commands and subscription services.
    4.Tabs- Click on different tabs to change available commands.
    5.Ribbon- Provides access to basic windows and Inventor commands.
    6.Panels- Shows available commands on the current tab. Different set of panels for each tab.
    7.Browser- Organizes the history of how the contents of a file was created. Can be used
         to edit features.
    8.Graphics Window- Displays the graphics of the current file, and  acts as the users workspace.
    9.ViewCube- Shows current viewpoint and allows you to change the orientation of the view.
  10.Navigation Bar- Contains common view commands. additional commands can be added using the
          drop down arrow.
  11.Status Bar- Displays messages about the current process.
  12.Capacity Meter- Exhibits information on the number of parts in current document, number of
          documents open, and total memory usage.

Inventor has several file type associated with it, each of  which pertains to a specific working environment. Of these, the most basic, and commonly used is the "Part" or .ipt file.  To create an new part file simply open inventor and click [New] on the Launch panel. A dialogue box will open with a number of file and base unit types. Open the desired .ipt  template to launch a new part.

A template will initially open with the default name Part1 (the number will increase as subsequent Part files are created).  On the left of the program window a browser will have become visible. This browser, as previously stated, organizes the modeling features, and tools that will have been use to make the part. As work is done the list will become longer and show directories of relationships held between certain features (like that between extrusions and a sketch which we'll cover later). Currently the list includes the part name, an origin folder (containing original x,y,z axis and their corresponding planes), and also Skecth1.

Sketch1 refers to the 2d grid that presently occupies the work environment. This is the starting point from which you begin making your part. In sketch mode design the simple outline of your part , but don't worry about trying to draw all the details yet. Almost all parts are made from multiple sketches that either add or remove material from the part. The initial sketch simply provides a base from which to create future elements.

To begin drawing use the tools located in the [Draw] panel of [Sketch] Tab at the top of the screen. These will consist of basic geometric tools (i.e. line arc, polygon rectangle, etc.) as well as patterning and modifications tools, some of which have several application options that can be accessed by clicking the arrow next to their picture.

As you draw you may wish to take advantage of the tools located in the constraint panel. The instruments found here apply relationships between two objects that keeps their geometry relative to one another (ie tangent lines, parallel segments). This guarantees the proper orientation of geometry and also can reduce the dimensions required to create a drawing.
      
           (NOTE hovering over tool images will bring up some text and animations exemplifying the use of the tool)

*Follow along with the video to begin drafting the base structure of the featured pendant.
     (It is strongly suggested that you watch this full screen in at least 720p so as to read the displayed dimensions.
      Also make sure annotations are on)
 

Once a sketch has been completed and [Finish Sketch] has been selected, Inventor's work environment changes into modeling mode. The transition between sketch and model modes is marked by the removal of grid lines from the screen, the sketch entering a isometric view, and the ribbon displaying the [Model] tab tools. In model mode, the user has tools sets which mainly allow them to create 3D rendered objects from existing sketches, or modify solids already present.

To begin making a solid for a sketch, tools found in the [Create] tab are implemented. Activate a command by selecting it with the mouse. A dialogue box will appear containing the options for the selected function. From here you can determine the profile(s) and solid(s) that will be affected by the action, as well as the output type, whether the action will add or remove material, and the extents (distance)/direction  the feature will stretch to. Enter in the desired values and a preview of the action will appear in the graphics window. Applying the command will create the feature.

After a feature has been created an icon will appear in the [Browser] with a default name of the command and a number (i.e. Extrusion1). though the number attached to these names increases as more of the same feature is created, so as to differentiate between occurrences, it is strongly suggested that you rename them to keep track of what they created in the model. for example if [Revolve] was used to make a disc, rename the feature "Disc". To rename features slowly double click on the name then enter a new one. (fast clicks opens the edit feature dialogue box)

Creating a feature from a sketch additionally results in the "consumption" of the used sketch, making it no longer visible. If no visible sketches exist in the work environment no other [Work] panel tools can be used. Either create a new 2d sketch ( on a solid's face, or  other existing plane) using the [Create 2D Sketch] tool or make an old sketch visible.

Consumed sketches can still be found in the browser by expanding the icon of the feature which consumed it (the nesting of these elements is referred to as a "Parent-Child Relationship", showing that the feature is geometrically dependent on the sketch). To make the sketch visible, right click its name and select [Visibility] from the menu.

Some other important tools in model mode are found in the [Modify] and [Work Feature] panels
                 Modify- Commands alter existing solids often emulating machining tools.
                 Work Features- Create custom features (planes, axis, points) that aid in the creation
                                                  of other modeling feature and sketches 

*NOTE- the view cube and Navigation bar can be used to reorient your view, to make new sections of your part visible

Follow the Video to continue with creating the featured pendant

The second half of the modeling video.

Although a Part file can hold several solids within it, generally the pieces of a entire structure are created in more than one document.  It is, however, still often important to view all these features as a single unit, so as to guarantee everything has been appropriately designed. Situations such as these call for a new file type know as  "Assembly' (.iam).

In an Assembly multiple Parts can exist within the same document. Inventor references the Part files and generates one, or more, occurrences for each within a shared work environment. An Assembly can be created by one of two main methods

Launch Method
    1.  When you first open inventor select [New] From the [Launch] panel
    2. Open the desired .iam file
    3. Add parts by activating [Place] on the [Component] panel and opening the
        appropriate part file (then click on the Graphics window to place the desired number
        of occurrences)

From Part to Assembly
    1. While in a Part file, activate the [Manage] tab of the [Ribbon].
    2. Select [Make Components] from the [Layout] panel
    3. When the [Make Components] selection dialogue box opens select the solid you wish to add to
        the assembly then hit [Next>>]
    4. Hit [OK] on the next dialogue box and an Assembly with the selected part will be created
         *(saving will make part files for each solid)

*Note: Parts placed in an assembly are "linked" to their part files. if the part file is altered it will be reflected in the assembly. the same applies to the part file if a change is made in the assembly.

*In addition to "placing", parts can be created directly in the assembly using the [Create] command on the [Component] panel (a new part file will be created)

Once within the assembly parts can be oriented with respect to one another, into a unit, as they would be at the end of production. To do this the designer implements tools found on the [Position] panel, namely [Constrain] and [Assemble]. These commands establish relationships between the 3D geometry of the solids, thereby restricting their "Degrees of Freedom" (the number of ways they can move). For example creating a [Mate] constraint between the axis of a hole and that of a pin results in the pin and hole sharing an axis. Additionally the two are unable to move from one another in any direction which would result in the separation of their axis. They can however, still rotate around, and move longitudinally along this axis. *(The more constraints you apply the less a part can move.)

Some other applications of an assembly include:

Dynamic Simulations & Animations: Located on the [Environments] tab. Exhibit the moving
                                                                    relationships between parts by "driving" constraints
                                                                    (moving parts on their remaining degrees of freedom)

                                    Stress Analysis: Also on the [Environments] tab. Evaluate stress endured
                                                                    by parts under a variety of circumstances.

                                   Designing Tools: On the [Design] tab. Used to create standardized components
                                                                    from fasteners (bolts and pins) to power transmission
                                                                    (gears, bearings, cams, etc.)

                                Material Selection: On the [View] tab. Change what different components are
                                                                    made of.

*Video...........you know the drill.

Computer renderings of a part are incredibly useful and efficient, from a design and cost standpoint. Dimensions can be entered to exact specifications  and simulations can be run to test how pieces interact, and the amount of stress they receive. What if you were testing something such as, how comfortable the object feels in your hand? You can't run a simulation for that. You need the actual part. Fortunately Inventor still holds the answer.

Inventor supports a service know as 3D printing (aka Rapid prototyping) which produces real life objects from digital models. This is done by splitting the design into numerous cross sectional layers. A device then takes these cross sections and prints them one on top of another, slowly building up the final model. In engineering there are two main methods of printing.

Fused Deposition Modeling- A bead of molten material (generally a thermoplastic such as ABS) is extruded from a heated die head. the die follows a specified tool path building the each layer of the part. Heat from each subsequent layer fuses it to the previous layer resulting in a semi-solid part.   Parts are typically supported by a secondary material which either breaks away from the model or is dissolved by a specified solvent  This type of printing is excellent for creating durable functioning prototypes, however printing detail is more limited, and removing support fill can be difficult in tight spaces.
               
3D Powder Printing- A printing head, similar to that of an ink-jet printer, passes over a bed of dry powder. The print-head sprays a binder over the the powder along the cross section of the part being made. a new layer of powder is deposited over the part and the print-head applies more binding agent. The process is repeated until the final part is made. This type of printer offers greater detail at the cost of structural integrity. Parts Can be strengthened with epoxies.

In order to prototype one must have access to a 3D printer. You can take advantage of one of the many printing services found online or even purchase your own printer (i.e. a MakerBot, or RepRap) . In either case you must first create a file that these devices can use.

The file type, in Inventor, associated with 3D printers is the .stl or ( Standard Tessellation Language) and is generated very easily.

1. Open the part you wish to print ( for the tutorial open the [Pendant] file created through the assembly)
2. Open the Inventor Application Menu and click the Arrow next to [Print]
3. Select [Send to 3D Print Service]. A dialogue box will open.
4. Edit the options as desired, but ensure the [Units] (found by pressing the [Options] button) are the
    same as those you designed the part with.

        *NOTE (if you have multiple solids in the document you can set the the [Print Range] to [All Visible] 
                      or [Selected]. to use [Selected], activate the solids in the document that you wish to print,
                       by left clicking them with the mouse, before accessing the printing window.)

5. Hit [OK] then save the file. Now you can either send it to your own printer or a to company you find on the web
     (Price varies. average cost $15-25 per cubic inch.)

        *NOTE ( For printing jewelry, Powder Printing is Strongly recommended ,
                        due to the increased detail.)

If you desire, you can simply take the prototype  you created and finish it with filling materials and paint, or you can take a step into making production models.

How can you make a production model you ask? You mold and cast it obviously.

Here are some other Instructables, regarding mold making, that I recommend.

https://www.instructables.com/id/How-to-make-a-Green-Lantern-ring--including-a-glow/
https://www.instructables.com/id/How-to-make-a-two-part-mold/

Thanks for reading, and don't forget to vote.