Flexible filament can be fun to 3D print but challenging to get right the first time. Learn to master your Ender 3 with TPU and flexible filaments.
3D printing beginners often start with PLA because it’s an easy material to work with. While PLA can produce some excellent parts, there might come a time when you need materials with different properties for a specific project.
That’s where flexible filament comes in: TPU is an example of a flexible material you can use to create some different types of models. From RC car tires to coasters, this material unlocks new possibilities when added to your arsenal.
It usually takes a bit of heartbreak and frustration to learn something new, and few users of 3D printers put on their first roll of filament and crank out perfect prints from the start. TPU, in particular, might cause some issues with an entry-level printer like the Ender 3. Fortunately, this guide should give you a strong start.
Is It Possible?
In forums, you’ll often see complaints that thecan’t print in TPU or flexible filament because of the way it’s built. The extruder, the Bowden tube system, and the hot end will likely be mentioned as insufficient in one way or another.
However, there are hardware modifications to address each of these issues as they relate to TPU. We’re going to cover some of these in the next two sections.
The Cold End
Discussions around the Ender 3’s extruder will generally point out the likelihood of the filament bending in the cold portion, after it passes the toothed gear. This is a bigger problem with flexible filament because… it bends, and the motion of the extruder motor won’t be transferred properly.
An upgraded all-metal extruder can help with the potential bending of the filament in the extruder, but if you’re on a smaller budget, this extruder upgrade from Thingiverse addresses the issue. Some users have even recommended using a straw to keep the filament straight – the key is to avoid bending of any kind.
On the topic of upgrades, be sure to check out our list of the best Ender 3 upgrades and mods.
The Hot End
As stated earlier, an upgraded all-metal hot end can make printing with TPU easier since it eliminates the PTFE tube that could cause issues with flexible filament. In addition, these types of hot ends can reach higher temperatures, which gives you access to a whole range of other materials. Be sure to check out our list of the best hot ends.
The Bowden Tube
The Bowden tube can sometimes be at fault for allowing the filament to bend too much, causing a problem. The upgrade kit linked above has a fresh Bowden tube, but you can also opt for a higher quality tube, which should result in easier movement of the filament to the hot end.
TPU prints with a hotter nozzle temperature than PLA, usually somewhere around 220–230 °C, while many users print PLA at or around 200 °C. You will probably also find that you need to turn up the temperature of your heated bed and may need to use tape or hairspray for bed adhesion, even if your PLA sticks to your bed with no aid.
In addition, reduce your speed to 40 mm/s. If your extruder clogs or gives you messy, stringy prints, you may need to adjust your retraction to as low as zero. You will also need to adjust the nozzle distance from the bed, as TPU doesn’t require as much “squish” as PLA.
As with all slicer settings, the key to success is experimentation. Different brands of TPU may require different settings, but the good prints are just one experiment away!
Feature image source: ModBot / YouTube
License: The text of "Ender 3 & TPU: How to 3D Print with Flexible Filaments" by All3DP is licensed under a Creative Commons Attribution 4.0 International License.
Subscribe to updates from All3DP
You are subscribed to updates from All3DP
You can’t subscribe to updates from All3DP. Learn more…