How to print with the flexible filament Filaflex?

Flexible filaments are great allies when creating products and allow us our imaginations to run free in the field of 3D printing. But just as it is a material with different properties to those of rigid filaments, its printing form is also different and a series of guidelines must be taken into account for the final result to be satisfactory. Let's get to know them!

Print flexible filament

The saying "You can't push a rope" couldn't be more accurate as we get down to business when it comes to printing flexible filament on a 3D printer. Most of them will succeed. However, we will try to explain the most common issues to avoid and how to manage to 'push a rope' and achieve a good flexible filament print quality at acceptable speeds. In this case, replacing the rope with the flexible Filaflex filament for 3D printing.

What is Filaflex?

  • Filaflex is an elastic TPU filament, thermoplastic polyurethane.

  • It stands out for its excellent elastic properties, that is, after stretching it recovers its original shape without breaking or deforming, as long as the elastic limit of the material is not surpassed.

  • It has a high friction coefficient.

  • It is a soft and elastic grip material with multiple applications: textile, fashion, prosthetics, insoles, elastic parts for machines, protective covers for devices, surgical organs, etc.

  • It must be remembered that Filaflex is characterized by high adhesion with the printing bed, so it does not need a hot table, blue tape, Kapton tape, lacquer or any other adhesive substance.

  • It is odourless, resistant to solvents, acetone and fuel.

  • In addition, it is not toxic and can be in contact with the skin (for more information on its medical or food use, contact our team).

The Filaflex range is made up of 4 filament models that are classified according to their Shore hardness. The Shore hardness of elastic filaments is measured on the 'A' scale. The higher the number of its Shore hardness on the scale (95A), the less elastic it will be and the lower the number (60A) the more elastic and softer it is. The 4 Filaflex models are as follows: 

Filaflex 95A 'Medium-Flex'

It is the easiest flexible filament to print in the entire range and the most compatible with all 3D printers on the market, including Bowden type printers.

Filaflex 82A 'Original'

With an 82A Shore hardness, it is the best-selling and most appreciated filament in the range.

With it, we obtain a great elasticity in the pieces while it is easy to print in most printers.

Filaflex 70A 'Ultra-Soft'

With a Shore hardness of 70A, it is a filament that offers advanced elasticity and softness.

It must be printed on direct extrusion printers and is incompatible with 'all metal' hotends.

Filaflex 60A 'PRO'

With the lowest Shore hardness of all, 60A, it is the most elastic filament in the entire range and even in the flexible filament market.

It must be printed on direct extrusion printers and is incompatible with 'all metal' hotends.

Guidelines to bear in mind when printing with Filaflex

Next, we are going to detail what are the main challenges or issues when printing with flexible filament and the ways to solve them in order to print this material without any problem.

Challenge 1 | Filament jam in the extruder

It occurs when the filament is not correctly inserted into the hotend due to the long distance or gap that may remain between the extruder pulley and the filament inlet hole. There may also be the possibility that the filament clogs the carriages, causing the steps to jump.

 Solutions to filament jam in the extruder 

To avoid this issue, we must eliminate any gap that may exist between the thrust pulleys and the inlet hole of the extruder hotend. In this way the filament will be fully guided from the pulleys and the hotend, avoiding jams or tangles. In some extruders it is very simple, especially in REP-RAP printers, but in others it can be somewhat more complex. Next, we are going to see two options:


Placement of a small support wedge between the extruder pulleys and the inlet hole of the flexible filament to the hotend. There are several models that you can print in 3D, this model or this other one among many more.


Print a new extruder designed for flexible filament. Like, for example, this one designed by Steve Woods from Gyrobot, one and even this other one. You also have this option available, among many others.

Challenge 2 | Friction

Another issue with flexible filament printing is the excessive friction that occurs before and after the extruder. This friction can cause issues that result in more pressure on the motor pulley and ultimately lead to filament feed conflicts.

Solution for the back of the extruder 

Keep the minimum distance between the motor pulleys and the hotend tip.

This will prevent the flexible filament from compressing or increasing the diameter inside the barrel.

Insert PTFE tube into the hotend barrel.

On the other hand, it is recommended that our hotend has a PTFE tube and that it is very well refrigerated. Bowden-type extruders are the most problematic, as we mentioned earlier, but you can still use them as long as the feed tube is made of PTFE. In Bowden-type extruders, it is recommended to use 2.85 mm flexible filament. It will provide us with more thrust force than the 1.75mm one.

 Solution for the front of the extruder 

Insert the flexible filament directly into the extruder.

If possible, the recommendation is to Insert the filament directly into the extruder (direct extrusion printers), thus avoiding the use of filament guide tubes (extrusion tube or Bowden type printers). These tubes cause high friction on the flexible filament causing several issues.

But, if, on the other hand, you have no choice and you use this type of tube, make sure that they are made of PTFE (Teflon) material. Pneumatic or silicone tubes are not optimal. Also, make sure to eliminate any bends or kinks that the tube may have by trying to make it as straight as possible to avoid unnecessary friction.

Challenge 3 | Internal pressure of the hotend

And finally, we also must bear in mind the internal pressure of the hotend. Once we have solved the previous challenges, regarding the extruder and the hotend, we move on to a third key factor, which is the diameter of the nozzle. If we use a nozzle with a very small diameter, for example, 0.2 mm, the pressure inside the hotend will increase, therefore, we will not be able to print at an acceptable speed.

 Solution to eliminate the internal pressure of the hotend  

After testing with 0.2, 0.3, 0.4, 0.5 and 1 mm nozzles, as we increase the diameter of the nozzle we will be able to increase the printing speed proportionally. The 1mm nozzle can print high-quality parts as we can still maintain a 0.3mm layer height. It should be said that, depending on the complexity of some perimeters, they will lose some detail, but as regards the resolution of the part in the z-axis, it will still have an optimal quality. Both the 0.4 and 0.5mm nozzles maintain a good print quality/speed ratio, but if you want to experiment, Richrap's Quick-Fit Extruder is great for quick extruder change for REP-RAP style printers or even the Steve Wood design.


Download Filaflex print profiles

We also recommend that you download the printing profiles for CURA, SLICER or SIMPLIFY3D corresponding to each material, which you have at your disposal in the 'Download files' section in the product sheets for each material, as well as in the 'Print Parameters' section, which you can access from the main menu of the web.

Purchase Filaflex and Flexible Filament Compatible Printers

Currently, there is a wide variety of 'low cost' 3D printers' and with an exceptional value for money that prints the filaments of the Filaflex range phenomenally. If you are interested in printing with these materials, we recommend models such as the Artillery Sidewinder x1 printer.

If you have any further questions, we also recommend that you consult our FAQ.

Do not hesitate to contact our team if you want more information or help in relation to this matter. We will be happy to help you and assist you.

Creativity is Flexible

Happy printing!

Filaflex 95A

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1 Review(s) 
The TPU filament Filaflex 95A, 'Medium-Flex', is the perfect flexible filament for beginners in flexible printing. It is a semi-flexible filament, compatible with all 3D printers on the market, including bowden-type extruder printers (with tube).. Shore hardness 95A 500% stretch Medium elasticity Compatible with all printers Resistant to solvents and...

Filaflex 70A

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7 Review(s) 
TPU Filament Filaflex 70A, 'Ultra-Soft', is a highly elastic and advanced filament from the Filaflex range for 3D printers. Shore hardness 70A 900% stretch Very high elasticity Resistant to solvents and fuel Odourless No hotbed required Made in the EU

Filaflex 60A

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5 Review(s) 
TPU Filament Filaflex 60A 'PRO' is the most elastic and flexible filament on the market for 3d printers. This filament is only suitable for the most experienced and daring 3d printing enthusiasts using flexible fialments. Shore hardness 60A 950% stretch Extremely elastic Resistant to solvents and fuel Odourless No hotbed required Made in the EU