Additive Manufacturing / 3D Printing

  • Applications
    FDM Process
    PolyJet Process
    FDM Build Types
    Wall Thickness & Tolerances
    Secondary Processes
    File Preparation
    STL File Size & Faceting


    There are many applications for which you can use rapid prototypes, for example:

    • Concept modeling:
      The freedom of multiple design iterations without cost penalty.
    • Form, fit and function testing:
      MAKE-PARTS prototypes help engineers and designers determine form, fit and function before investing in tooling.
    • Fine feature detail:
      Using our PolyJet technology, MAKE-PARTS can build small prototypes and those that require fine feature detail, such as models and toys.
    • Design verification:
      Test your new products on the market and ensure that your design is right before going to mass production.
    • Masters:
      You can use MAKE-PARTS prototypes as masters for vacuum forming, investment casting and many other methods.
    • Jigs and fixtures:
      Why invest in heavy, expensive jigs and fixtures that require assembly when you can build fixtures in one piece using MAKE-PARTS. And because they’re made of thermoplastics, they’re lighter and easier to handle.
    • Marketing tools:
      Need to show your new concept to create a buzz? Build a MAKE-PARTS prototype. You can paint it, plate it or just simply show it.
    • Production mockups:
      Get a highly accurate and functional prototype to ensure that your design is correct before investing in production.
    • Thermoforming:
      Use thermoforming as an inexpensive alternative to plastic molding or other forming methods.

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    FDM Process

    ABS is an ideal material for conceptual prototyping through design verification through direct digital manufacturing. The marriage of ABS with FDM (Fused Deposition Modeling) technology gives you the ability to create parts direct from digital files, in a variety of standard and custom colors. This material is ideal for the rapid production of prototypes, tooling and the direct (tool-less) manufacturing of production parts. ABS is a strong, durable production-grade thermoplastic used across many industries.

    ABS is widely used in applications where impact-resistance and structural strength are necessary. It is accurate, durable and robust enough for field testing or demonstration units. Because of its excellent dimensional stability, it is ideal for pre-production rapid prototypes that can accurately predict performance of injection molded parts.

    Maximum Build Dimensions
    • 10 x 10 x 12 (inches)
    • 254 x 254 x 304 (mm)
    • Larger parts can be built in pieces and bonded if necessary.
    Achievable Accuracy

    Parts are produced within an accuracy of +/- .005 inch or +/- .0015 inch per inch whichever is greater (+/- .127 mm or +/- .0015 mm per mm whichever is greater).

    Layer Thickness: Horizontal build layers are .254 mm (.010 in.) or .33 mm (.013 in.)

    Note: Accuracy is geometry dependent.

    Available Colors

    White, Natural (Off White), Black, Grey, Red, Orange, Fluorescent Yellow, and Olive Green

    Note: On-screen and printer color representations may vary slightly from actual colors.

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    PolyJet Process

    PolyJet is a resin like material similar to stereolithography (SLA). Clear PolyJet Resin works well for prototypes that require smooth surface finish and high feature detail. Parts from this material can absorb paint or dye, be chrome plated, used as a master for silicone molds and have been used in investment casting. Clear PolyJet parts will have a semi-translucent appearance, which can be enhanced with sanding and buffing. Typical industries included toys, foot wear, architecture and any industry where feature detail and surface finish are required.

    Maximum Build Dimensions
    • 19.7 x 15.7 x 7.9 (inches)
    • 500x 400 x 200 (mm)
    • Larger parts can be built in pieces and bonded if necessary.
    Achievable Accuracy

    Layer Thickness – Horizontal build layers down to 16 microns (0.0006 inches).

    Build Resolution – X axis: 600 dpi. Y axis: 300 dpi. Z axis: 1600 dpi.

    • ± 0.005 under 4 inches is typical
    • ± 0.008 is generally the worse case but it is geometry dependant

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    Stereolithography or SLA use 3-D CAD data to convert liquid plastic materials and composites into solid cross-sections, layer by layer, to build highly accurate three-dimensional parts. An ultraviolet laser cures a liquid resin into very thin layers, including interior and exterior cavities, to closely mimic injection-molded parts. SLA Systems rapidly manufacture parts of different geometries at the same time and are designed to produce prototypes, patterns or end-use parts of versatile sizes and applications.

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    FDM Build Types

    FDM parts can be built in three different types depending on your needs.

    • Solid-Parts:
      Parts are built completely solid, which creates a stronger but more expensive part. Customers have used parts built this way as low volume temporary production parts to help get their product to market quicker and then substitute them with actual production parts when tooling is ready.
    • High Density Sparse Fill:
      Parts built this way have a highly dense woven interior to reduce cost and overall weight. Customers have used these parts in application where lighter weight or more porous parts are required, such as vacuum forming. The woven interior lets air past through the entire parts allowing for even and consistent vacuum forming.
    • Low Density Sparse Fill:
      Parts built this way have a low density woven interior and is the least expensive built type. Parts are light weight but not a strong and are generally used for presentation and low impact proof of concept models.

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    Wall Thickness and Tolerances

    Thin Shells and Walls

    Models with a thin shell or walls may:

    • Break when printed or shipped
    • Print with errors
    • Be impossible to print
    • Be vulnerable to breaking
    Minimum Thickness Requirements

    Sometimes wider is better, especially if you’ve ordered a prototype only to be met with unexpected holes, gaps, missing pieces or flimsy walls. As an easy way to make sure what you see is what you get, measure wall thickness before having a prototype made.
    For example: The thinnest wall, using standard slice resolution, that can be built using Fused Deposition Modeling (FDM) technology is 0.04 inches (1.016mm).

    If you use photopolymer (PolyJet) technology, you can create parts with thinner features. Most thin walls will build, but may be somewhat fragile and are susceptible to damage during support removal, testing and handling.

    Moving Parts

    Before you upload your model, be sure that there is enough clearance between moving parts such as the following:

    • Gears
    • Cogs
    • Links in a chain

    If you do not, your prototype may be a solid, non-moving object. To ensure the parts of your model move, you may need to make clearance adjustments.

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    Secondary Processes

    MAKE-PARTS offer numerous secondary model finishes which include, but not limited to:

    • Assembly – Parts that are larger than our build size and need to bonded before shipment.
    • FDM Smoothing – Parts can be finished to near injection molded quality.
    • RP Tempering – Increase part strength, make parts water or air tight, or create living hinges.
    • EMI Shielding
    • RFI Shielding
    • Flame Retardancy
    • Soft Feel – Give you parts the look and feel of rubber.
    • Painted Finishes – Please specify colors when getting your quote.
    • Clear Coating
    • Laser Engrave Logos- See our CNC Laser Section of the website for more information.

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    File Preparation

    File preparation is an important part of rapid prototyping. If the source file is not converted properly data can be lost, resulting in a part that looks different than you expected.

    Nearly every rapid prototyping and digital manufacturing (end-use parts) organization uses STL files to build parts, so it is important to understand what STL is and what settings you can adjust to get the part you really want.

    Almost all of today’s CAD systems are capable of producing an STL file. For the user, the process is often as simple as selecting File, Save As and STL. Below are steps for producing high quality STL files from a number of today’s leading CAD systems.

    General Steps
    • Most CAD packages will have a couple of options that affect the quality of the STL.
      • Changing a “Deviation” type of value will alter the overall output or tessellation.
      • Changing an “Angle Tolerance” type of value will alter smaller details in your file.
    • The tighter these parameters, the more triangles placed on the surface of the model.
      • Simple geometries tend to be a few hundred kilobytes in size.
      • Complex models will range from 1-5MB in size and still produce good parts.
      • For many models, files larger then 5MB may be unnecessary and often result in more time to get your quote and models back.
    • In all cases, export your STL file as a binary file. This saves on time and file size.

    Please note, these are general guidelines and may not work or in some cases, produce the best possible STL file. Please consult your user’s guide or the software developer’s for more information or technical support. Should we determine that your STL file is not adequate for production, we will contact you for an updated file.

    If you are unsure that your file is properly exported there is a free program you can download called MiniMagics. This is an .STL file viewer software that allows you to import, save and compress STL files, as well as view parts and detect bad edges and flipped triangles. Download MiniMagics


    • File
    • Export
    • Save As > STL
    • Enter File Name
    • Save

    STL settings: How to change STL settings and MAKE-PARTS’s recommendation.

    • Tools > Options
    • File Types tab
    • Configure File Types: STL
    • Normal Deviation: 5

    (Smaller deviations will produce a smoother file, but the file size will get larger)

    AutoCAD (Versions: R14-2000i)

    • At the command prompt type “FACETRES”
    • Set FACETRES between 1 and 10. (1 Being low resolution and 10 high resolution for STL Triangles)
    • At the command prompt type “STLOUT”
    • Select Objects
    • Choose “Y” for Binary
    • Choose Filename


    • File > Export > Rapid Prototype File > OK
    • Select the part to be prototyped
    • Select prototype device > SLA500.dat > OK
    • Set absolute facet deviation to 0.000395
    • Select Binary > OK


    • Right Click on the part
    • Part properties > Rendering
    • Set Facet Surface Smoothing to 150
    • File > Export
    • Choose .STL

    Mechanical Desktop

    • Use the AMSTLOUT command to export your STL file.
    • The following command line options affect the quality of the STL and should be adjusted to produce an acceptable file.
      • Angular Tolerance – This command limits the angle between the normals of adjacent triangle. The default setting is 15 degrees. Reducing the angle will increase the resolution of the STL file.
      • Aspect Ratio – This setting controls the Height/Width ratio of the facets. A setting of 1 would mean the height of a facet is no greater than its width. The default setting is 0, ignored.
      • Surface Tolerance – This setting controls the greatest distance between the edge of a facet and the actual geometry. A setting of 0.0000 causes this option to be ignored.
      • Vertex Spacing – This option controls the length of the edge of a facet. The default setting is 0.0000, ignored.


    • File > Export > Model
    • STL
    • Set chord height to 0. The field will be replaced by minimum acceptable value.
    • Set Angle Control to 1
    • OK

    ProE Wildfire

    • File > Save a Copy > Model
    • Change type to STL (*.stl)
    • Set Chord Height to 0. The field will be replaced by minimum acceptable value.
    • Set Angle Control to 1
    • OK


    • File > Save As
    • Select File Type > STL
    • Enter a name for the STL file
    • Save
    • Select Binary STL Files

    SolidDesigner (Version 8.x)

    • File > Save
    • Select File Type > STL
    • Select Data
    • OK


    • File > Save As
    • Set Save As Type to STL
    • Options
    • Set Conversion Tolerance to Inches of Millimeters
    • Save


    • File > Save As
    • Set Save As Type to STL
    • Options > Fine > OK
    • Save

    STL settings: How to change STL settings and MAKE-PARTS’s recommendation.

    • File > Save As
    • STL > Options
    • For a smoother STL file, change the Resolution to Custom
    • Change the deviation to 0.0005in (0.004 mm)
    • Change the angle to 5

    (Smaller deviations and angles will produce a smoother file, but the file size will get larger.)


    • File > Save As
    • Set Save As Type to STL
    • Save


    • File > Export > Rapid Prototyping
    • Set Output type to Binary
    • Set Triangle Tolerance to 0.0025
    • Set Adjacency Tolerance to 0.12
    • Set Auto Normal Gen to On
    • Set Normal Display to Off
    • Set Triangle Display to On


    • Choose Stereolithography from Export options
    • Enter the filename
    • Click OK


    • Save Copy As
    • Select STL
    • Choose Options > Set to High (for highest quality surface)
    • Enter File Name
    • Save

    Note: The “High” setting will also produce the largest file size. From Low, Medium to High, the Hairdryer sample file in Inventor went from about 6.7MB to 17.6MB to 50MB.

    3D Studio Max

    • First check for errors
    • An STL object must define a complete and closed surface. Use STL-Check modifier to test your geometry before export your object to STL.
    • Select an object.
    • Click “Modify”
    • Click “More…”
    • Select “STL-Check” under Object-Space Modifiers
    • Select “Check”
    • If there are no errors, continue to export the STL file by:
    • “File” > “Export”
    • Select “StereoLitho [*.STL]” in “Save as type”
    • Select location in “Save in”
    • Enter a name in “File name”
    • “Save”
    • “OK”
    • Export To STL dialog:
    • Object Name: Enter a name for the object you want to save in STL format.
    • Binary/ASCII: Choose whether the STL output file will be binary or ASCII (character) data. ASCII STL files are much larger than binary STL files.
    • Selected Only: Exports only objects that you selected in the 3D Studio scene.


    • Select AEC object. Go to 3D SOLID menu & select convert to 3D SOLID
    • After that you will have an option: Erase selected object [Yes/No] “Yes”: Enter Y
    • All the objects are converted into 3D Solid using the same procedure for each AEC objects
    • Select a single solid for STL output… (Must be ONE solid to export to STL)
    • Command entry: stlout
    • Select objects: Use an object selection method and press ENTER when you finish
    • Create a binary STL file? [Yes/No] “Yes”: Enter Y


    Revit doesn’t allow direct export to STL files. We have to first save in dwg file and open in AutoCAD to create STL files.

    • Go to 3D view
    • Go to File menu, select Export CAD format
    • A dialog box opens, select “option”
    • Scroll down the drop down menu (3D view only) & select 3D polymesh
    • Select “AutoCAD 2004 DWG” in “Save as type”
    • Next open the saved file AUTO CAD
    • Enter “Explode” on the command menu
    • Select the object and press “ENTER”
    • All the objects are converted into 3D solid
    • Select a single solid for STL output… (Must be ONE solid to export to STL)
    • Enter “stlout” or “export” on the command menu
    • Select objects: Use an object selection method and press “ENTER” when you finish
    • Create a binary STL file? [Yes/No] “Yes”: Enter y

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    STL File Size & Faceting

    Angle, Deviation & Chord Height (Faceting & Smoothness)

    If your part was rougher or smoother than you had hoped, you can change the angle, deviation and chord height to create the right outcome. Faceting is determined by the relative coarseness of curved areas of the adjoining triangles. The most common variables are deviation or chord height, and angle control or angle tolerance. Following are three examples of various STL faceting outputs determined by varying angle, deviation and chord height: Coarse faceting (poor), excessive fine faceting (fair) and good quality faceting (best).

    • Coarse Faceting (poor):
      When the faceting is too coarse you can see flat spots on curved surfaces. The flat spots in the STL file will show up when the part is produced. Coarse faceting is almost always caused by the angle setting being too high, or the deviation/chord height settings being too large, or a combination of both.
    • Excessively Fine Faceting (fair):
      Fine faceting can cause delays in processing and uploading of parts because of the larger size. Increasing the resolution excessively does not necessarily improve the quality of the produced part. This is caused by the angle settings being too low, or the deviation/chord height settings being too small, or a combination of both.
    • Good Quality Faceting (best):
      The happy medium between the two extremes is good quality faceting, just detailed enough so that features build to the file dimensions, while being simple enough to maintain a manageable file size.

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