2.    A real person and the scanner software, both of whom have more information on the part than SolidWorks Premium version, can better eliminate the unneeded, redundant scan points. We use a method that keeps the most important ones for modeling use. (More technical details on the methods used are here in An In-Depth Look.)

3.    Our IGES data consisting of less than 20K points per level is imported as separate 3D sketches into any version and most years of SolidWorks. This can be rotated in real time to “see” where data points (physical part surface) are in relationship to the model being developed. The 3-D sketch does not blank out like it would if more data points were included. The points for the profiles, general outside surface and possibly inside surfaces are in separate IGES levels. The other alignment axes, planes and such are in their own layer too. These all come in as separate 3D sketches which can be shown or hidden individually inside SolidWorks.  Each 3D sketch can be made a different color in SolidWorks to help avoid confusion. (The IGES color of the layer does not import correctly.) An example of what is imported into SolidWorks in this page Throttle Body.

4.    The data cloud is aligned to useful xyz axes and translated to a logical origin location with respect to the part. SolidWorks does not provide an easy and precise way to align parts of a data cloud or imported part to real world axes unless it is part of an assembly. When you make / generate a model of a skewed part it will be skewed & you need to rotate the model to give it a desired XYZ axes and origin. Alignment features (planes, axes) are included with the IGES data so you can easily line up the 3D sketches as a separate SolidWorks part as part of an assembly if you so desire.

5.    You can use the data cloud to check how far off the completed model surface is from the digitized part for every surface by using the measurement tool in SolidWorks.

6.    You can use the scan profiles we provide to help sketch curves simply by turning off geometry snap and just tracing over the data points with the line/arc or spline tools.  The scan profiles give high density data points in planes where the sketches are required to make / generate features.  The Low Resolution scan point can be used in the same manner but it is more difficult to determine which data points are valid in the current sketch plane without rolling the cloud and sketch around. (The profiles are generated in the scan post-processing step by a SolidWorks modeling person, so they should be in useful places.)

7.    We can optionally provide the actual profile sketches as lines based on statistical point matching instead of points.

8.    The CAD alignment surfaces, circle centers, and axes are based on statistically generated averages of hundreds or thousands of points of the high density scan data. These are more accurate for something like a sand casting than the 3 points you can use in SolidWorks. There are still plenty of points remaining in the general less than 20K points set for the flat/smooth areas to do a 3 point plane.

 

Why can’t I just use the old casting as a pattern to sand cast identical new ones?

1.    The pattern needs to be larger than the desired part because the molten metal shrinks as it cools.  Typically the pattern that gets pressed into sand for aluminum castings is 2 to 3 percent larger than the original. 

2.    The molten metal does not shrink uniformly while cooling.  Our service cleans up warped and distorted surfaces on your part and supplies a corrected part to your casting vendor.  You can also review our model and/or drawings and request changes before any casting begins.

 

Can you send us samples of raw data, simplified scan data and SolidWorks model files?

Sure. We can supply you with sample IGES scan data files and the SolidWorks models via email. We can supply native model files with a full feature tree in SolidWorks 2011 and 2012. Note that the simplified scan data and SolidWorks model are 3-20 Megs in size and may not work in your email system. The raw scan data files are often several hundred megabytes and need to be sent on a CDROM. We are happy to do this. 

 

Can you supply the simplified data in other formats?

We can supply the simplified data files in stl, obj, wrl , scn and xyz formats but have found that xyz works with programs that process scan point data. We typically do not save any image data (or it is in grey scale) from the original part to save on downstream processing. We also do not save the polygon mesh (surface triangle vertex coordinates and direction.) Many general purpose scanning formats include this information. If you need this information and just want the raw scan data with no models, we can work this on a case-by-case basis. (The un-simplified water-tight STL files of course are provided in STL format or other scanner format we both agree upon.)