by TeamPlatform, App note, No Comments

Aug 17

Speed quoting process for 3D Printing with the bounding box (it’s automatic)


by TeamPlatform, App note, Comments Off

Aug 17

TeamPlatform automatically calculates the bounding box, and this can help the quoting process for 3D printing.  But there is much more to consider than bounding box alone.  Let’s take a look at other factors that help speed the printing process.  In case you are new to TeamPlatform technology, you might want to check out this post on how TeamPlatform can help 3D Printing first.

What bulk Geometric Properties are important in quoting 3D printing?

  • Bounding box (max width / max height / max depth)
  • Volume
  • Surface area

Typical Ways to Generate a Quote (without TeamPlatform)

  1. Get geometry data
  2. Import into CAD System
  3. Set Tessellation Properties (for an example for AutoDesk Inventor, check here)
    (there are going to be different setting for different file types.  It is important that you have a CAD license and workstation for the CAD system that can open up the file you receive)
  4. Export as STL
  5. Import STL into Printing Software
  6. (It is important that you have Printing Software licenses and a workstation for the Software)
  7. Obtain Geometric Information from Printing Software
  8. Use Geometric Information to generate quote
  9. Send Quote, Win Order
  10. Print Part

Team Platform helps in the quoting process by automatically extracting geometry information, and can be a big help in Step #1 and #9, too.

How does the bounding box actually help in Quoting?

If you know the bounding box size, then you can be sure that the volume of the object inside of the bounding box is less than or equal to the bounding box volume.  This calculation is automatic for any 3D file uploaded to TeamPlatform.

Volume Calculation of Bounding Box

Calculating the bounding box volume is simple.  Multiply the dimensions together.  The part will never have a volume larger than this maximum.

H x W x D = Max Enclosed Volume.  

Max Cost based on Bounding Box

Finding the maximum cost to produce the part is also simple.

(Max Enclosed Volume) x (Material Cost per Unit Volume) = (Max Part Cost).  

Sometimes quoting or estimating Rapid Prototyping / 3D Printing can be a little more complex but in general, the part volume plays the major role in the estimated cost of the prototype.  The count of facets is usually not an important factor in the cost to print the prototype although high polygon count (# of facets) may pose a problem for older printing systems and software.  Additionally, if the resolution of the features is very high (detail is very high, features are very small), then this may be indicated by the facet size and some low resolution printers may not be appropriate.

More Sophisticated and Accurate Quoting

Of course, TeamPlatform provides some more sophisticated calculations of the geometry, like surface area and part volume, which can help provide a more accurate estimate.

Extracting the Volume and Surface Area

The Volume and Surface is automatically calculated for upload scan data.

Estimated Volume = Volume

Estimated Surface Area = Surface Area

Volume calculation provide a more accurate estimate (ideally a perfect estimate) of the amount of material the will be required to print and therefore factors directly into the cost.  The cost of a part based on material in this instance is as shown below.

(Volume) x (Material Cost per unit Volume) = Part Cost 

Calculation the Volume of Thin-Coating

If your Rapid Prototyping service bureau is providing a coating service or procedure similar to RePliform (which, for example, can add a layer of metal to strengthen and finish a prototyped part), then the thickness and surface area and coating thickness are going to factor into the quoting estimate.

Calculating the volume of a thin exterior skin on a part is simple.  If the surface area is not thin (for example, the thickness of the coating is less than 4X smaller then the thickness of the part or the part has areas of high curvature, then this approximation begins to fail.  As a rule of thumb, it is a very good approximation for a thin coat volume approximation

(Surface Area) x (Coating Thickness) = Approximate Coating Volume

Typically when coating, you want to produce a finished part that matches the nominal geometry of the model.  If the part you are prototyping has a high ratio of surface area to volume, then the Coating Volume can be subtracted from the part volume, to help provide an accurate quote for sheet or thin-walled parts.  (Inner Volume) = (Part Volume) – (Coating Volume), which is also straight forward.  You can offset-inwards geometry to print, where the final coat offsets-outwards to match the nominal.  Both CAD and 3D printing software are typically able to negatively offset the geometry so that the part can be used.

For a quoting system that is based entirely on the volume of the produced part where a thin-coat is used, the cost based on material volume would be as follows:

(Inner Volume) x (Inner Volume Material Cost per Unit Volume)

+ (Coating Volume) x (Coating Volume Material Cost per Unit Volume)

= Total Cost of a Coated Prototype

Deriving the equation above, similar to the other equations in this post, is based on simple arithmetic.

The volume of a thin coating on a part with large surface area can begin to approach the inner volume of the printed part.  Cost can be estimated with surface area and part volume information.

Skipping the Import/Export/Import/Export Steps for CAD Models

Some other things that you might not expect from TeamPlatform is that CAD models, including native CAD models work just as well as STLs.  Geometric properties like bounding box and volume are available from CAD Files (there is not need to convert to an STL or worry about chord length or chord height).  When a (service customer’s) file gets to TeamPlatform, the geometry is automatically calculated to help speed the quoting process.

Forget about Chord Height and Edge Length.  Just upload the original CAD model (SolidWorks, IGES, STEP, Pro/E, CATIA, etc.) to get the geometry properties.  TeamPlatform automatically calculates Geometric Properties from native CAD.

Quick quotes help get quick orders.  After you get the order, all you need to worry about is printing (and packaging and shipping the part to your customer).

    Comments are closed.