We Are Learning 3D Printing Through Our Personal Experience…
ColorFabb XT-CF20 is a copolyester based carbon fiber composite material that is based on the Amphora 3D polymer from Eastman Chemical and is loaded with no less than 20% specially sourced carbon fibers suitable for 3D Printing. The XT-CF20 filament uses the XT-Copolyester instead of the PLA/PHA from COlorFabb and the result is a filament with higher strength and toughness as well as resistance to higher temperatures before starting to get soft. The not so good thing compared to PLA/PHA is that a heated build plate is recommended for using the XT-Copolyester for your prints to stick better, although you could end up getting good results on 3D printers without a HBP as well. The combination of XT-Copolyester with 20% of carbon fibers in the ColorFabb XT-CF20 is very good and prints using this filament, we have previously tested carbon fiber-based filaments with PLA such as Proto Pasta’s Carbon Fiber PLA, but the XT-CF20 does seem to do better job.
The XT-CF20 does seem to be less brittle and a bit more stiffer with a better resistance to higher temperatures thanks to the 80 degrees Celsius glass transition temperature. The carbon fiber-based solution from ColorFabb also does seem to contain a bit more carbon fibers – 20% as opposed to just 15% in the Carbon Fiber PLA that we have previously tested. ColorFabb XT-CF20 does require higher printing temperature with 240-260C recommended, it is recommended to be printed using 40-70 mm/s speed and a heated build plate (if available) is recommended at 60-70C. Also do note that carbon fiber filament is more abrasive than standard filament, so it can shorten the life of standard brass nozzles by increasing the wear level. So it is recommended to use a printing nozzle with some sort of coating such as the ones we have tested from Performance 3-d or AVN Swiss.
We have tested printing with the ColorFabb XT-CF20 carbon fiber filament on our trustworthy MakerBot Replicator 2 3D printer with some useful upgrades such as a coated nozzle and added HBP, so we had not trouble or worries using the XT-CF20 filament. The first test was to try and print using the carbon fiber filament on a cold build plate, we’ve already had some experience using the XT-Copolyerster filament using the ColorFabb XT Transparent Filament earlier this year before upgrading the 3D printer with a heated build platform. Interestingly enough the XT-CF20 carbon fiber filament does seem to print easier and to stick better than the XT transparent filament probably due to the carbon fibers. All we’ve had to do was to enable the use of rafts and we got a great quality print on our first try at 240 degrees Celsius printing temperature and going to 260C did not make much difference. We were able to print smaller parts at 90 mm/s printing speed at 0.2 mm layer height without any trouble, though you would probably want to reduce the speed a bit for finer details. Also no trobule removing the raft from the actual model and getting a good quality base of the part that was 3D printer on the raft.
Next was to test the ColorFabb XT-CF20 carbon fiber filament using the heated build plate at the recommended settings and see how things will go without having to use a raft when printing. We have started with 240C extruder temperature and tried with both 60C and 70C temperature of the HBP, but with both we’ve had trouble with the base of the 3D printer part to stick properly on the build plate. Moving to 250 degrees Celsius for the extruder we had the part sticking better and remaining on the build plate, but the base of printer part has shown that it still did not stick perfectly at either 60C or 70C HBP temperature. Going to 260C for the extruder and we got the filament sticking well at either 60-70C temperature for the heated build plate. The only problem that remains and that is associated with the high extrusion temperature is that the filament oozes from the nozzle a bit more when the printing head moves over longer distances to continue printing for larger objects. Other than that, with the right settings the ColorFabb XT-CF20 carbon fiber filament does seem quite easy to work with and provides good results, now we only need to print some parts that would be stress tested like something for an RC model.
We got a spool of the ColorFabb XT filament (the standard transparent one) that is based on Eastman Amphora 3D polymer as an alternative to PLA filament to try it out. ColorFabb says that their XT filament, unlike PLA, is absolutely neutral from color and completely transparent. So if your 3d print project requires some transparency the they recommend to give XT a try, the problem however is that this filament is apparently not as easy to print as standard PLA. It is more like printing with ABS and although heated build platform is not required it is recommended to have it and use it with this filament as otherwise you might get warping of the printed objects. The ColorFabb XT filament also needs higher printing temperature and the advantage it brings is that it is stronger and resists higher temperatures as compared to PLA.
The manufacturer recommended printing temperature for the ColorFabb XT filament is between 240-260 degrees Celsius, with a 40-70 mm/s extrusion speed and the use of a heated build platform that is at 60-70 degrees Celsius. Since our MakerBot Replicator 2 3D printer does not come with a heated build platform we have tried printing the ColorFabb XT on a cold build platform. This has caused us to struggle a bit until we find the best settings that would allow us to print without warping and get good enough results, but we have managed to do it. The settings that worked for us were 245 degrees C for the extruder, 40 mm/s extrusion speed and using rafts for printing as well as turning off the cooling fan that cools down the extruded filament. You should note that the MakerBot Desktop software does not come with a feature that disables the cooling fan upon user request for a specific model, but thankfully the Simplify 3D software that we also use does come with such a feature available for the MakerBot Replicator 2 3D printer.
On the photo above you can see a direct comparison between the ColorFabb XT filament (their transparent version) on the left versus a MakerBot Neutral PLA. The PLA seems a bit less transparent and has some yellowish tint while the ColorFabb is whiter and more transparent. When talking about transparency however there are some important tips that need to be taken into account with the ColorFabb XT filament to get the best results. To get the most transparency out of the print ColorFabb recommends to try the following: disable cooling fan for the entire print; print slowly at about 20-40 mm/s; increase flow rate, so the perimeters melt together; print at rougher layer heights, such as 0.27mm – 0.35mm. Also taking into account the infill you are going to be using depending on the type of the 3D model you are going to be printing is important when you use transparent filaments in general and not only ColorFabb XT.
Our conclusion about the ColorFabb XT filament is that it definitely has some useful advantages over traditional PLA filaments such as the increased strength and temperature resistance. We have tried soaking 3D printer parts using the ColorFabb XT in water with temperature of 80 degrees Celsius and the parts remains pretty strong and solid, unlike PLA that will get really soft at temperatures of over about 65 degrees. The drawback that a heated build platform is recommended for easy and problem free printing makes the filament less attractive for users that have 3D printers with no heated build platform. For such people we would recommend to not go for the ColorFabb XT as although you might still be able to get decent prints most of the time you would most likely have problems printing at times especially with bigger and more complex models.
The European filament manufacturer ColorFabb has announced the release of a new special filament using carbon fibers mixed with thermoplastic material that should be as easy to print on most 3D printers. ColorFabb XT CF20 is a copolyester based carbon fiber composite material that is based on the unique Amphora 3D polymer from Eastman Chemical and is reinforced with 20% specially sourced carbon fibers, making it perfect for printing parts which need high stiffness. Combining carbon fibers in filaments material is not a new idea, but ColorFabb has been able to combine a lot of desired properties into 1 new material. Still the company does warn users that due to the abrasive nature of the carbon fibers using this new filament will accelerate the nozzle-wear of brass nozzles, much faster than other standard types of filaments, so they recommend to use nozzles from Stainless steel or hardened copper alloys.
ColorFabb XT-CF20 Carbon filament features:
– Extreme High Flex Modulus (6.2 GPa) / twice as stiff as PLA
– Moderate strain at break (8-10%), so no extreme brittle filament, butt toughness
– High Glass Temp. (Tg = 80C)
– Very high Melt strength
– Very high Melt Viscosity
– Good dimensional accuracy and stability
– Low odor / Styrene Free solution
– Easy processing on many platforms
– High attractive matt black surface
The ColorFabb XT-CF20 special filament with Carbon fibers is already available for pre-order with the first orders expected to start shipping at the end of February. The price of a single spool with a weight of 750 grams in either 1.75mm or 2.85mm diameters is €49.95 EURO or roughly $57 USD. This makes the price of the Carbon fiber reinforced filament from ColorFabb pretty much the same as the one that the USA-based Proto-Pasta sells their Carbon PLA filament. The advantage here is that ColorFabb is based in Europe and if you order from Europe it should come cheaper than if you get the USA product, however although the two filaments seem very similar there are some differences. You should be aware that the Proto-Pasta Carbon PLA filament that we have already tested recently is mixing carbon fibers with PLA, but ColorFabb is using the Amphora 3D polymer instead and thus it has slightly different properties.
The Eastman Amphora 3D polymer is a low-odor, styrene-free choice that is uniquely suited for 3D Printing applications. With Amphora, makers can create items that are more functional, durable, efficient, and attractive. Amphora also complies with certain U.S. Food and Drug Administration (FDA) regulations for food contact applications. The XT-CF20 Carbon filament as well as other ColorFabb XT-Copolyester based filaments are supposed to offer stronger and more detailed parts, offer higher temperature and better chemical resistance as compared to standard PLA filament. The side effect is that you need to use higher temperature of the extruder when printing, 240-260 degrees Celsius are recommended with printing speeds of 40-70 mm/s and the use of a heated build plate is also advised. This means that you need higher temperature, a bit slower printing speed and a heat build plate for best results – things that are not required for PLA-based Carbon fiber reinforced filaments, although the heated build plate may not be required. We are going to be testing ColorFabb XT-Copolyester 3D printer filament soon on out Makerbot Replicator 2 3D printer that does not features a heated build platform, so that we can see how well these filaments will work in our case. ColorFabb recommends that you disable the extruded filament cooling fan of 3D printers that are not equipped with heated build plate when using their XT filaments for the first centimeter and/or using rafts in order to get best results. If the Amphora 3D polymer used in the ColorFabb XT-Copolyester filaments does indeed work well with no warping when not printed on heated build platform we do plan to also try out the new ColorFabb XT-CF20 Carbon Fiber filament when it starts shipping.