How to 3D Print TPU Filament on Ender 3 & Ender 3 (Pro) (Flexible Filaments)

You might be thinking is it possible to print TPU on an Ender 3 and the answer is yes. We are going to look in-depth at how to print flexible filament materials like TPU on Ender 3 printer.

What is TPU?

TPU is a Thermoplastic Poly Urethane flexible material that can bend, stretch, doesn’t break when pulled apart, and even can be knotted. 

3D printing with Flexible filaments can open up a lot of opportunities meaning it can serve a wide range of applications. 

Printing with TPU filament needs some experience and settings on your 3D printer, thus it is difficult for beginners to get hang of it. Thus, if you are new to 3D printing, then get yourself going with PLA first as it is the easiest material to print with. 

TPU is a flexible material whose properties can enable one to produce many different parts for a wide range of applications. However, when you try to print TPU on a printer like Ender 3, you will get into problems for sure. 

There are also some hardware modifications that can be made for Ender 3 to smoothen the TPU printing on it. 

This blog is a detailed guide on how to print TPU on Ender 3 and Ender 3 Pro also covering some details on the flexible filament types. 

About TPU FIlament 

TPU (Thermoplastic Poly Urethane) is one of the types of Elastomers. This TPU filament can be printed on any properly configured FDM 3D printer. As compared to other flexible filaments, TPU is slightly stiffer. 

TPU exhibits medium strength which makes it easier to handle and print. It also has good durability and can handle higher tensile and compressive forces as compared to other filaments like PLA, ABS.etc 

TPU Filament Ender 3 and Ender 3 Pro Printing Process

Flexible Filament Ender 3 and Ender 3 Pro printing can be made effective by modifying certain hardware as below

TPU Print Performance

When it comes to TPU print performance, it slightly shrinks and prints with less distortion. To print with TPU, a heated print bed is not mandatory but can be used whenever needed. The Nozzle printing temperature lies between 210 to 230 DegC and it varies between different brands of TPU. 

TPU doesn’t produce fumes when extruded and is not a soluble material. It is hygroscopic and not suitable to print food-grade objects. Due to its hygroscopic nature, it has a tendency to get spoiled over time. The printing speed for TPU is very low at 30 mm/s due to the fact that the flexible material cant be easily extruded through the nozzle. 

Extruder Type for TPU 

To get high-quality models with TPU, it needs to be printed without filament jams. This can be achieved with a Direct Drive Extruder. On the other hand, both Ender 3 Pro and Ender 3 TPU settings along with calibrations should be maintained in place which is needed for TPU printing. TPU can even be printed on Bowden extruder with Ender 3 (Pro)

Try and test small parts before printing the larger objects to ensure and optimize the settings. 

Applications of TPU 

TPU parts have many applications such as medical devices, mobile covers, footwear, power tools, rubber mats, drive belts. etc

The chemical and physical properties of TPU make it eligible to be used in high-demand applications such as automobiles, breathable films, sports goods, wires, and cables. etc 

TPU properties lie in the mid-range between rubber and plastic. It exhibits several advantages such as great tensile strength, good load-bearing capacity, and high elongation resistance before breakage. 

The Extruder Assembly For TPU (Bowden / Direct Drive / Full-Metal)

When printing TPU on Ender 3 or Ender 3 Pro, the flexible filament is subjected to bending after the gear wheels in the extruder. This affects the smoother movements of the extruder motor and the flexible filament will not pass easily. 

If you upgrade to a full-metal extruder then it can help to overcome the bending of the filament. Thingiverse has a part that can reduce the bending furthermore and keep the filament straight. This can be an affordable solution.  

Upgradation to the Direct Drive Extruder on Ender 3(Pro) could be another potential way to print the flexible TPU filaments accurately. This also eliminates the need for Bowden tube and reduces the filament pathway length. As the filament path gets shorter, traction increases, and this helps to produce successful 3D models with flexible materials like TPU. Adding to this, if the PTFE tube is removed and all-metal hot end is used, then it allows to reach higher temperatures. 

Slicer Settings for TPU 

The printing nozzle temperature of TPU ranges from 220 and 230 DegC when compared to PLA which is printed at 200 DegC. TPU demands the usage of adhesive materials for bed adhesion such as hairspray or adhesive tape.

TPU needs to be printed at 40 mm/s and if you notice the extruder clogging or thread-like prints, then it is an indication to reduce retraction to zero. Adding to this, the distance between nozzle and print bed is also to be varied as TPU doesn’t need much squeezing as compared to the normal PLA or BAS 

In spite of all these slicer settings, one needs to do experiments a lot to get the desired results. These settings will also change for different TPU filament brands. 

Flexible Filaments Fulfill Variegated Consumer Demands

Consumers today expect accuracy and precision in the products they buy and this demand can be fulfilled by 3D printing. When it comes to custom product manufacturing, be it 3D printed garments or prosthetics, 3D printing is the key solution. 

Rubber is usually preferred for applications that need flexibility and elasticity. However, rubber cannot be 3D printed, hence the material is needed which will be like rubber and also can be 3D printed. Those materials are Elastomers and polymers which are called flexible materials. When the properties of polymers and elastomers are combined then we will get 3D printable materials called TPEs (Thermoplastic Elastomers).

Thermoplastic Elastomers: Overview

Thermoplastic Elastomers are polymers that exhibit elasticity similar to rubber material and the degree of elasticity varies as the TPE material type & chemical structure changes. The elastomers of this type can derive all the benefits of thermoplastics and help in 3D printing. TPE filaments are of various types, subtypes with different materials, and selecting the right one is a challenge. TPU is one of these materials. 

Thermoplastic Elastomers: Properties 

Some of the properties exhibited by Thermoplastic Elastomers are 

• High durability 
• Good Electrical property and good vibration damping 
• Impact resistance is high such as chemicals and weather
• TPE is resistant to tears and abrasions / low and high temperatures (-30 to +140 Deg C)

 

Best TPU Filament Brands

NinjaFlex TPU filament is known for its flexibility and can produce slushy prints effectively. It is extremely flexible due to its Shore Hardness of 85A. The nozzle temperature should be between 210 to 225 DegC with a printing speed of 30mm/s

Sainsmart TPU is another popular TPU filament brand having a shore hardness of 95A which makes it slightly stiffer than other TPU filaments. Nozzle temperature should be 200-220 DegC and a heated bed of 30 – 50 Deg C is needed. Optimal print speed is 20-30mm/s.

Conclusion

TPU is one of the preferred flexible filaments for flexible applications. It can be printed without a heated bed and yet offers great adhesion to print bed. Warping on TPU is also minimal and highly abrasion-resistant as compared to other filament materials.