How To Rate Your 3D-Printing Filament
With 3D printing, a good filament can make the difference in your print job. 3D printers can share horror stories about their experiences with bad filament.
While there are ways to test filament with expensive mechanical testing equipment, I wanted to develop a way to test filament at home. With my background as a science teacher, I’m all too familiar with writing testing procedures. For this blog, I’ll develop a score based system to rate your filament.
For this test I’ll compare Proto Pasta Stainless Steel PLA to Colorfabb nGen filaments.
Points Based Scoring
For my testing procedure I wanted something I could do at home without special testing equipment. For each category there will be a point scale. The cumulative points at the end of the test will give the final score for the filament.
For the entire test, you will need to print samples on a calibrated 3D printer.
These samples were printed on a Lulzbot Taz 5, 0.2 mm resolution, 70 C bed temperature. Colorfabb nGen was printed at 230 C, while Proto Pasta Stainless Steel PLA was printed at 215 C.
Category 1: Flexibility
This will require a protractor, clothing pins or other clamps, and a ~7 cm length of filament.
Clip the filament to a table about 1 cm from the end of the sample on top of the protractor.
Slowly bend the filament around. The filament gets a point for every 15 degrees that it can bend without snapping. 12 points if the filament can bend the full 180 degrees.
Colorfabb nGen: Bent the full 180 degrees, 12 pts
Proto Pasta Stainless Steel PLA: Snapped at 70 degrees, 4.3 pts
Category 2: Color
For this test, print a sample under normal conditions with a calibrate 3D printer. Compare the print to the original filament to see if there is a difference in the shade or tone of the samples.
3 points if the color is the same from spool to print.
2 points if there is a slight shift in color from spool to print.
1 point if there is a noticeable shift in color from spool to print.
Colorfabb nGen: It did lighten a bit, 2 pts
Proto Pasta Stainless Steel PLA: While it did take on a metallic shine, the tone and shading were consistent. 3 pts.
Category 3: Starting Quality
For this one you will look at how well the print starts printing with the recommended bed surface. Both of these filaments were printed on top of blue painters tape.
2 points if the filament sticks to the bed well and does not come loose during printing.
1 point if the filament comes loose during the start.
0 points If the filament does not stick to the build plate, or requires restarts.
Colorfabb nGen: 2 pts
Proto Pasta Stainless Steel PLA: 2 pts
Category 4: Warping
A filament is only good if it stays in place and prints in a predictable manner. For this your print should stay parallel to the build plate without warping our curling on corners.
3 points for no warping at all.
2 points for warping around sharp corners or bends.
1 point for warping off the bed.
0 points for warping that ruins the print.
Colorfabb nGen: 3 pts
Proto Pasta Stainless Steel PLA: 3 pts
Category 5: End of Print
For this you are looking at what it takes to remove the print and process it. Does it come off the build plate cleanly, or does it require some effort?
3 points if the print pops cleanly off the build plate.
2 points if the print comes off with some scraping.
1 point if the print requires significant effort or leaves residue behind that is difficult to scrape off.
0 points if the material sticks to the plate so strongly that you worry it can damage the build surface.
Colorfabb nGen: This did bind tightly to the blue tape, requiring a new strip of tape on the build surface. 2 pts
Proto Pasta Stainless Steel PLA: Popped cleanly of build plate. 3 pts
Category 6: Environmental
For this category, you look at how comfortable you are working around this filament. If you plan to run your filament for bulk orders, this can determine of you need special environmental equipment to print comfortably.
2 points if there is no noticeable smell or fumes.
1 point if there is a noticeable or pleasant smell that you can live with for a long duration.
0 points if there is a toxic fumes that will require ventilation for extended use.
Colorfabb nGen: I noticed a slight onion smell that did not agree with me, making me slightly queasy. 1 pt
Proto Pasta Stainless Steel PLA: No noticeable smell. 2 pts
Category 7: Special Considerations
This is a category that applies more to exotic filament blends then standard filaments. When you get a filament, you should consider if you are willing to spend the money for upgrades for your 3D printer.
1 point if you can use the filament by changing just the settings in your slicer.
0 points if the filament requires additional / hardened nozzles, or other upgrades to print for a long duration.
Colorfabb nGen: 230 C is a unique temperature for filament, but that can be controlled in the slicer : 1 pt
Proto Pasta Stainless Steel PLA: The filament is extremely abrasive (it feels like a fine emery board), and the company recommends a hardened or steel nozzle with an orifice bigger than 0.4 mm. In printing, the filament did chew up the idler arm on my print head, which would have to be replaces with frequent use. If you print with this on a regular basis, you will have to install a hardened nozzle. 0 pts
Category 8: Processing / finishing the print
After you print your object, you will have to clean it up to break any sharp edges or rough spots. You will also have to look at the methods available to apply a finish to your print to get the desired result. This is based on the factory recommendations for this filament.
2 points if you can use chemical or mechanical processes to finish your print.
1 point if you can use mechanical processes only.
0 points if this filament is too weeks to handle any process without special treatments.
Colorfabb nGen: The company does not have a recommended chemical finishing process. It does work well with sanding and trimming sharp edges. I had some problems removing tape residue from the print though. 1 pt.
Proto Pasta Stainless Steel PLA: The company does not have a recommended chemical process for treating their Stainless Steel PLA, though you may try using Salt water to try to rust the filament, which you can do for their Magnetic Iron PLA (a review of that will be in a future blog). Being Stainless Steel, you could easily polish it on a grinding wheel. The company also sells a polishing kit. 1 pt
Colorfabb nGen: This new filament from Colorfabb was similar in many ways to it’s XT line of filaments. The 230 C printing temperature is more appealing to printers with lower end hot ends. I did have some problems with it sticking too much to the build plate. I did notice an onion smell that did not sit well with me.
Final Score: 24 / 28
Proto Pasta Stainless Steel PLA: This exotic filament can give your prints a metallic finish with some effort. The metal filings in the filament made it more brittle than normal PLA, so you will have to watch for that while printing. It did print well, but you will need a hardened nozzle and spare parts if you print for extended time.
Final Score: 18.3 / 28
Disclaimer: Proto Pasta sent me the samples at their own expense, with no expectations in return for their review.
If you would like 3D-PT to review your filament, please leave a comment below or email me, firstname.lastname@example.org. I will be happy to review any and all samples of your filament.