Different companies use different methods for testing their filaments, and you either don’t really know what those methods are, or maybe you don’t even understand what the numbers mean. As a result, you have to decide which filament will best fit your needs based on the statements that different companies use when advertising their product, such as “This filament is 5X stronger than […]”, instead of being able to use a standardized method to easily compare the different filaments available. Having a standardized method for testing and comparing filaments is crucial, especially considering that something as common as PLA will have different performance depending on who the manufacturer is.
Here is where Filapedia comes in. This website hosts the Official 3D Printing Filament Database. Every single filament added to the database includes all the important information about the filament along with a complete and understandable set of results from a new standardized and open testing method created by us.
Each filament includes the following important information:
• Official Name
• Main Material
• Special Properties
• Glass Transition Temperature
• Recommended Nozzle Temperature
• Recommended Bed Temperature
• Is it Abrasive?
• Requires Heated Chamber?
• Requires Part Cooling Fan
- Official Name
- Main Material Additive
- Special Properties
- Glass Transition Temperature
- Recommended Nozzle Temperature
- Recommended Bed Temperature
- Is it Abrasive?
- Requires Heated Chamber?
- Requires Part Cooling Fan?
You will also find information about the availability of the filament’s:
• Spool Weight
• Purchase Links
The procedure includes testing of a filament’s physical characteristics and performance such as:
• Layer Adhesion Strength
• Compressive Strength
• Impact Resistance
• Flex @ 10kg
• Flex Break Point
• Elongation @ 50kg
• Elongation Break Point
• Average Diameter
• Average Diameter Tolerance
Each of the previous tests is conducted on a different model specifically designed and printed in a certain orientation for that specific test. Below you will find detailed information on how each model is prepared (sliced and 3D printed) and tested using the testing jig, minimizing as much variables as possible which could affect the testing procedure.
Slicing & Printing
All test models are sliced using Cura 3.5 with most settings left with their default values, and others changed according to the most commonly used by the 3D printing community. Three of the same testing models are printed in a single batch. Some of these models are quite small, so printing three at once increases the time spent in each layer, as if it were a larger model. This yields more “real world scenario” results. Test prints are always printed using the same printer, a Prusa Steel Black Edition.
The layer height, infill percentage, infill type, number of perimeters, and bottom/top layer settings are set as follows for all prints:
|Number of Perimeters||3|
|Connect Infill Lines||Yes|
The rest of the settings are left with Cura’s default values, except for printing speeds and retraction settings. These two might have to change with certain filaments like TPU and other flexible or brittle filaments that may require more or less speed and retraction. We try to keep this change as minimal as possible to prevent it from impacting results.
Nozzle temperature will always be set to the mean (average) temperature suggested by the manufacturer. For example, if the label reads 205°C -225°C, the temperature will be set to 215°C.
Bed temperature will always be set to the upper temperature value suggested by the manufacturer. For example, if the label reads 0°C -60°C, the temperature will be set to 60°C. Keep in mind that 0°C is simply considered as not using a heated bed, which means room temperature.
To keep temperatures consistent, all the printing process is done at a stable and controlled room temperature of 25°C.
The following are the complete settings used when printing the test models. Again, the only settings that might change according to the filament being tested are printing speeds, retractions, and temperatures. All other settings are exactly the same.
You can also download the Cura Profile we created to do the testing, the G-code, and the 3D files for all the test models by clicking on the following links:
The Testing Jig
Although there are some existing (and extremely expensive) machines that can perform the tests we will perform, we won’t use them. To test the performance of each test model in a consistent way, a custom rig was designed and made mainly from square steel tubing and some 3D printed parts. All forces were applied by either tightening a large screw eye, or by dropping a lever and leaving the hard work to gravity. All forces are measured using a hanging scale and a camera to record the scale’s highest measured value or a digital caliper to measure distortion. The following are some images of the custom jig.
FOTOS DE JIG
This may not be the most precise setup, but we have chosen to work this way because it is Filapedia’s mission to make all designs involved in the testing process publicly available as well as easy and affordable to recreate. To accomplish this, most materials used can be easily be found in any hardware store. This will allow any 3D printing enthusiast or filament manufacturer to recreate the procedure and perform their own testing, if desired, at a low cost. To keep things consistent and prevent adulterated results, all filaments registered in the database have been tested by us.
Also, due to the nature of our setup and the fact that printers cannot recreate a model’s geometry to perfection, we perform each test three times and then average the results to get a more precise result for each filament.
A complete BOM (Build of Materials) list and all design files are available through the following links if you want to build one of your own.
By printing all test models with the same slicer version, same settings, same printer, same room temperature and having a custom jig to do the testing, we can get reliable and repeatable results. But first, it is important to understand why the models have certain shapes, why they are printed on a certain orientation, and how forces are applied to them on the jig in order to understand the data each test will give us about the filament. The following is a precise description on how each test is conducted and why.
Layer Adhesion Strength
The layer adhesion test is used to measure how strongly layers bond to each other. To test this out, the test model is printed and tested vertically. This way, when tension is applied to the model, the print fails along the narrow area. The model just splits into two along a layer line. It is important to mention that the transversal area along this part measures 0.5 cm2. Because this model has only 20% infill, the area where two layers make contact is not really 0.5 cm2 but less. Again, our goal is to make easy-to-understand data, so we’ll still consider it as 0.5 cm2. To test the model, a loop of paracord is passed through each hole of the model. These loops are then secured to the bottom of the testing jig, and to the hanging scale. To apply tension to the test model, the nut that holds the eye screw is turned at a constant speed. Tension is applied until the test model breaks. The highest measurement is measured is recorded in kilograms. This test is done three times. Remember these measurements are kg/0.5cm2. Final results in the database are an average expressed in kg/cm2, so the three measurements are averaged out and then multiplied by a factor of 2. For example, if the scale read 45.5kg, 50.1kg and 48kg in the set of tests, to get the final result we would calculate:
((45.5 + 50.1 + 48)/3)x2 = 95.73kg/cm2
FOTOS LAYER ADHESION
The compressive strength test is used to measure how much compression the test model can handle before it breaks. This is a common test done on more brittle materials like concrete. Plastics, due to their inherited plasticity are very hard to break violently. To achieve a similar result, the design of the test model is particularly weak. In this case, the cylinder has a transversal area of 0.5cm2. To prevent the model from tipping over, there are two small 3d printed parts in the jig that help keep the test model in place. To apply a compressive strength to the test model, a loop of paracord is passed under the print and held to the hanging scale. Then the nut that holds the eye screw is turned at a constant speed. Tension is created by turning the nut, but due to the fact that the test model is being “stopped” by the jig, the test model is being compressed. The nut is turned until the test model breaks. The highest measurement is measured and recorded in kilograms. As always, the test is repeated three times. The result in the database is expressed in kg/cm2 so the average is then multiplied by a factor of 2. For example, if the hanging scale reads 78kg, 79.2kg, and 79.1kg in the three runs, to get the result we calculate:
((78 + 79.2 + 79.1)/3)x2 = 157.53Kg/cm2
The impact strength test is used to measure how much of an impact the test model can resist before breaking. This test is conducted using a pendulum at the right side of the jig. The very end of the pendulum has a bolt whose head has been machined to have an area of 0.5cm2 and is long enough to carry weights. A 3D printed guide ensures the pendulum swings straight towards the test model from a 90 degree angle, and a ball bearing reduces friction as it swings. The physics involved in this test can get intimidating, as it is an aluminum profile and not a “weightless” string that holds the mass of the pendulum. The mass is also off-centered from the profile’s axis. Yet again, for the sake of keeping everything simple to understand, we treat this as an ideal simple pendulum, whose impact force is easily calculated. Weights are added in increments of 0.25Kg and swung using the pendulum. Yes, this weakens the model internally as the weights are incremented, but it is still a good representation of impact resistance if the same procedure is followed for every filament. When testing the print, the heaviest weight that does not break the model is recorded. Then it is converted to the force in kilograms exerted to the test print at the moment of impact. In this case, the result would be shown in Kg/cm2. For example, if the three models resisted 15kg, 14.3kg, and 15.05kg, to get the result we calculate:
((15 + 14.3 + 15.05)/3)x2 = 29.56Kg/cm2
FOTOS IMPACT STRENGTH
Elongation @ 50kg
The elongation @50kg test is used to measure how much the filament can stretch given an applied tensile force of 50Kg. The test model is very similar to that of the layer adhesion test, but it is longer and has two tabs that are 50mm apart from each other. This extra length will create a larger total deformation than that of a shorter test model, so the results are easier to measure. Also, in this case, the test model is printed flat on the bed. If it were done vertically, the print would fail along a layer line just like the layer adhesion test. This test is conducted in a very similar way to the layer adhesion test. A loop of paracord is passed through each of the holes in the test model and secured to the testing jig and the hanging scale. The nut is turned until the hanging scale measures a force of 50kg. The tabs are used to measure the deformation caused by the 50kg using a digital caliper. In this case, the result in the database is presented as a deformation percentage caused by the force per cm. Remember, all tests are done three times. So, if the digital caliper reads 50.32mm, 50.23mm and 50.28mm, then the result would be:
((50.32 + 50.23 + 50.28 – 150)/150)x100 = 0.55%
FOTOS ELONGATION @ 50KG
Elongation Break Point
The elongation break point test is used to measure how much tensile force the filament can resist. The test model is the same as the elongation @ 50kg test. In fact, it uses the same test print as this is just a continuation of the previous test. The nut is simply tightened until the tensile force breaks the test print. The highest value measured by the hanging scale is recorded. In this case, the result in the database is presented as a force kg/cm2. Remember, all tests are done three times. So, if the hanging scale reads 60kg, 61kg and 60.8kg, then the result would be:
((60 + 61 + 60.8)/3)x2 = 121.2 kg/cm2
FOTOS ELONGATION BREAK POINT
Flex @ 10kg
The flex @ 10kg test is used to measure how much the filament flexes given a force of 10kg that pulls it from the middle. The test model is a simple bar with a transversal area of 0.5cm2 and two tabs that help align it in position with the jig. Again, the model is printed flat, or it would fail along the layer lines. It is important to notice that the model is supported and aligned from both ends by the jig, and the distance between the supports is 10cm. To flex the test model, a loop of paracord is passed under the print and then held to the hanging scale. Then, the nut that holds the eye screw is turned at a constant speed. When the center of the test print is pulled, the model bends upwards. The distortion caused by the force is measured in mm using a digital caliper. The distance measured is that between to bottom face of the test print and the top face of the reference. As always, the test is run three times. The result in the database is the average deflection in mm. For example, if the distance measured is 12mm, 11.6mm and 11.2mm in the three runs, to get the final result we calculate:
((12 + 11.6 + 11.2)/3) = 11.6mm
FOTOS FLEX @ 10KG
Flex Break Point
The flex break point test is used to measure how much force the filament can handle when flexed. The test model is the same as the flex @ 10kg test. In fact, it uses the same test print since this is just a continuation of the previous test. The nut is simply tightened until the tensile force flexes the test print to the point that it breaks. This time, the hanging scale is used to measure how much force is applied before it breaks. The force is measured in kilograms and averaged out between the three runs. To get the final result the average is multiplied by a factor of 2 because the result in the database is expressed in kg/cm2. For example, if the scale reads 24kg, 22kg and 23kg in the three runs, to get the final result we calculate:
((24 + 22 + 23)/3)x2 = 44kg
FOTOS FLEX BREAK POINT
The average diameter test, as its name implies, measures the average diameter of the filament. Theoretically, the average diameter should be the defined filament diameter; 1.75mm for example. Yet this not always the case. Most filament manufacturers have a diameter tolerance of +-0.5mm or better. Also, many manufacturers measure the length of filament they wind on a spool. Knowing the density of the filament they are able to calculate the weight. Yet, if their diameter is off, the weight will also be off and will not be compensated. So if the average diameter is 1.74mm, the filament might still be within spec, but if it was wound by length you would get less weight on the spool. This also helps determine if any flow adjustments might have to be made during for the printing process. Testing the filament is very easy, as we designed a custom jig that holds a digital dial with a precision of 0.001mm. The filament is inserted from the side, which pushes a bearing up. This movement is measured by the digital dial and recorded in mm. The test is done 15 times, once every two meters. The result in the database is average diameter of the filament rounded to the nearest hundredth, so it is simply the average of this results. For example, if the dial reads 1.75, 1.74, 1.745, 1.74, 1.745, 1.78, 1.785, 1.79, 1.785, 1.782, 1.778, 1.7793, 1.339, 1.74, 1.7456, in the fifteen runs, to get the final result we calculate:
FOTOS AVERAGE DIAMETER
Average Diameter Tolerance
The average diameter tolerance test is used to measure how good the tolerance of the filament is. Most companies have a diameter tolerance of +-0.05mm or less. This became the “standard” because achieving these results is relatively easy. After many tests, we noticed that almost all brands have their diameter within spec. The key difference between them is how much the diameter actually changes within that spec. This is the average diameter tolerance. The more the diameter fluctuates, the higher the average diameter tolerance. Therefore, a small average diameter tolerance means the filament has a very stable diameter, which translates to smoother prints. The data used to get this result is exactly the same as the one used in the average diameter test, only the calculation changes. To calculate this result, the standard deviation formula is used. Microsoft Excel includes it as a formula, which makes the calculation easier. Anyway, here is the full formula:
FOTOS AVERAGE DIAMETER TOLERANCE
The Official 3D Printing Database
So, the previous 9 tests are done to every filament eliminating as many variables as possible that could affect the testing procedure. Although all tests are not strictly scientific, nor are they done according to any ISO or ASTM standards (which there are none for FDM 3D printing), they are all done following the previous procedure. This itself creates a standardized method for testing filaments in order to be able to easily compare the mechanical properties of every filament.
Remember the database not only holds the results of our tests, but also other important information about the filament: its official name, brand, main material, additives, special properties, a short description, and much more. We ensure that all data has been collected prior to adding the filament to the database. If we don’t find all the information we need in the manufacturer’s website, we contact them to complete the data and register the filament.
Now that you know how we test each filament and understand what the numbers mean, check out the Official 3D Printing Filament Database and find the right filament for you!!!