Laser Sintering Accuracy Study
Overview: This report shows a typical month of Laser Sintering (LS) prototype output from the Stratasys Direct Manufacturing Austin facility. All measurement data for prototype parts built in April 2009 was included in this report, representing parts built using three machine platforms (2 HS/HiQ Sinter-Stations and an EOS P730) and three materials: Nylon 12 GF, NyTek 1200CF and DuraForm HST.
Data: The data represents 1859 data points from more than 600 parts; data provided is for overall extents measurements in the X, Y & Z axes. The data is aggregated and was not separated by machine platform or material. Parts included in this study represent a range of sizes from less than 1.000” to over 19.000”.
A plot of dimensional error as shown in figure 1 shows an important distinction of this study; many times RP accuracy is reported with data that excludes the Z axis. From the data in figure 1 it is apparent that the accuracy of parts included in this study is consistent in all axes. A Histogram of the data as shown in figure 2 illustrates the distribution of error for the entire data set. Of particular interest are the error distributions; of the data analyzed; 68% of the measurement errors fall within +/-.0068” and 95% of the measurement errors fall within +/-.0137” showing that on the vast majority of parts produced we exceed our stated tolerance of +/- .002” inch per inch or .015” (whichever is greater).
Conclusions: This snapshot of accuracy shows important distinctions about parts built with the LS process at Stratasys Direct Manufacturing. Of these distinctions accuracy is the most important. While we have a standard tolerance for LS parts it is important to note that we routinely deliver parts that are significantly more accurate in all axes than our operational tolerance allows. This underscores the repeatability of our process across multiple platforms running multiple materials. Because of the high level of process control, Stratasys Direct Manufacturing does not distinguish between X, Y or Z orientations when discussing accuracy capabilities. Regardless of platform, material, part size, or part orientation our process delivers parts that meet or exceed our stated tolerance.