Detecting anomalies in melt-extruded 3D printed parts using in situ data
Data files
May 07, 2024 version files 3.67 GB
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Build_Data.zip
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Contest_-_Final_Build_Logs.xlsx
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Pressure_Test_Data.zip
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README.md
Abstract
The data in this repository was gathered from a study to collect real-time, in situ data from polymer melt extrusion (ME) 3D printing, using a set of sensors to non-destructively identfy printed parts that contain defects. The data underwent variance analysis to determine an "acceptable" range of filament diameters and non-destructivley identify spatial regions of printed cylinders in multi-part builds that contain defects.
The data consists of two folders and a log meant to track procedural adherence for each cylinder printed, the introduced defects, or lack thereof, and the pressurization of the part. The "Final Build Logs" spreadsheet contains information regarding the two locations of the deformations along the 56 meters of filament needed to have no more than three anomalous cylinders out of the six printed cylinders, the date of the applied deformations to the filament, the initials of the researcher applying the deformations, the date that the build was printed along with the initials of the researcher who printed it, the part number, researcher initials, and date of the pressurization test for each cylinder within the build, and a comment describing any deviations from the procedure that play into the random error of the statistical analysis for each cylinder.
The "Pressure Test Data" folder contains a folder for each build. Within these folders are .tdms files containing metadata on the measurement system in the header and tab-delimeted values for the columns. The columns of interest to the study are X_Value, representing time elapsed, and pressure, which we evaluated on the values' exponential decay rate. The files also contain supplemental information such as a column for temperature (celsius), and the flow rate (SLPM Normalized). The "Build Data" folder contains in situ data from the sensor-equipped printer in a .csv file, the STL file for the build, the gcode file from the applied slicer settings, the AMRP file stores printer settings, and a .pdf file for the setup specifications.
Methods
The methodology involved an introduction of a material defect by varying the filament diameter of PETG filament and measuring the filament diameter values for the length of filament needed (9m) for a full cylinder three times before and after the defect was introduced using two orthogonally-positioned hall-effect sensors and a digital rotary encoder used to track the position along the filament of the cross-sectional diameter measurements. The data collected from the aforementioned process is not included in this repository, but the process preceded the creation of a defect that was both detectable in the in situ data and resulted in a printed cylinder with a statistically significant increase in its pressure decay rate.
Following this, six cylinders were printed on the same build plate and real-time in situ data from various sensors equipped on the desktop printer were gathered with the objective to map sensor data onto 3D coordinates to identify on which parts the identified anomalies landed. Determining the effect of filament diameter on the print quality involved pressurizing the printed cylinders with the introduced defect to 1 PSI, then evaluating for statistically signifcant increases in pressure decay rate of the cylinders.
As multiple parts were printed together layer-by-layer (opposed to part-after-part), the size of the anomaly was limited to be certain that no more than three parts out of six would contain anomalies.