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.


The MakerBot Replicator 2 3D printers are not among the most affordable ones and yet they do not have features in their build that more affordable devices on the market have by default. One such thing is the fact that the Replicator 2 3D printers rely on bushings instead of linear bearings for their moving parts along the three axes. While the use of bushings does work pretty well in the long term it could lead to reliability issues, so we have decided to try replacing them with linear bearings – something that needed some research and has turned out a not so easy task to do. What you should be aware of is that the replacement of the bushings with linear bearings should not lead to improvements in the quality you are getting, unless of course if you’ve already had some issues with the bushings.

The total number of bushings that you need to replace on the MakerBot Replicator 2 with linear bearings is 8 + 4 or 12 in total – there are 4 on the extruder head, and 2 on each side along with 4 more for the build table that moves along the Z axis. We are saying 8 + 4, because all of the bushings and respectively the linear bearings that you will need are different in size. The bushings for the Z axis or the build plate are actually with a bit larger size and we are still having trouble finding suitable linear bearings to replace them, so we actually changed only the 8 other bushings.


To replace the bushings that are used for the X and Y axis movement you will need 8 linear bearings that are marked as LM8SUU that are with a size of 8x15x17 mm (the actually used bushings are 1 mm shorter at 8x15x16 mm, but that is not a problem). The LM8SUU are the short version of the LM8UU bearings that will simply not fit in the MakerBot Replicator 2 as they are too big, so be careful that you choose the right model. The two bushings on the back for the build plate movement along the Z axis are with larger inside diameter, their size is 10x15x16, so the LM8SUU linear bearings won’t fit there. Unfortunately we are still not able to find a linear bearing with larger inner diameter and the same outside specifications (10x15x16 mm or 10x15x17 mm) as the LM8SUU to replace the two bushings along the Z axis, so we’ve settled only with installing linear bearings along the other two axes.


The disassembly of the X and Y axis movement mechanism is not that hard and you can repetitively quickly replace the bushings with bearings (you detach the whole mechanism from the top of the printer), unlike the more complex and hard to do disassembly of the moving mechanism along the Z axis. But as we’ve said the different bushings used along the Z axis and the act that we were not able to find suitable linear bearings to replace them, so there is no need to disassemble anything there anyway. One interesting things that we have noticed is that the bushings used for the extruder head were a bit different 2+2 in terms of visual appearance, but apparently also in terms of tolerance. The same goes for the bushings on the two sides, they are again 2+2 in terms of visual difference and tolerance, meaning that the ones with a bit larger tolerance move more freely as compared to the others. We have not noticed any difference in the behavior of the Replicator 2 after replacing them all with the same type of linear bearings, so we are not sure if there is a reason to use slightly different bushings and mixing them.


Fenner Drives, the maker of NinjaFlex a flexible 3D printer filament has announced a new variant of the NinjaFlex family, the SemiFlex 3D printer filament. Like the original NinjaFlex 3D Filament, SemiFlex material boasts flexibility, strength and reliability for your 3D printing projects, and is slightly more rigid to expand your printing possibilities. For the moment the new SemiFlex 3D printer filament is available in just 4 colors: Black, White, Blue and Red with the spool price for the standard more flexible NinjaFlex and the less flexible SemiFlex filaments being the same.

The new SemiFlex 3D filament features a consistent diameter and material properties providing reliable, high quality prints like the original NinjaFlex. It uses a patent pending technology for smooth feeding with a low friction exterior that allows smooth feed through filament guides. The filament provides high elasticity and excellent abrasion resistance, excellent build platform adhesion and bonding between layers and comes with a filament hardness of approximately 98A (50D) for SemiFlex as opposed to 85A for the NinjaFlex. The new SemiFlex 3D filament is available in both 1.75mm filament spool 0.50 kg weight and 3.00mm filament spool with a weight of 0.75 kg.


SemiFlex is best for the following types of projects:
– High level of detail
– Contain intricate parts
– High resolution text
– Unsupported vertical printing
– Shock-absorption needed
– Requires less flexibility than NinjaFlex Original 3D Filament

The SemiFlex 3D Filament Processing Guidelines recommend extruder temperature of between 210-225°C with no heated bed required for printing, though if you have and use one you might want to keep the temperature below 50°C. The recommended Print Speed is 30 mm/s, just like for printing with the original NinjaFlex filament, so prints using this material might require more time than what you would need as compared to when using standard PLA filament for example.