The NinjaFlex TPU Filament Project - Completed

I purchased a reel of NinjaFlex 85A filament to tackle this frequent subject on the R2 forums.

First off, my R2 printer has the following mods due to my exploring printing with Sainsmart TPU filament:

http://community.robo3d.com/index.p...eel-support-mod-for-c2-and-r2-printers.23519/

http://community.robo3d.com/index.php?threads/r2-extruder-mod.23518/

Next, I created a new material profile in Cura for the NinjaFlex 85A filament and set the parameters based on the data sheet from Ninja TeK. And I created a new quality profile using the Low Quality R2 Robo profile with factors adjusted per the filament data sheet. The Octoprint script for the R2 was adjusted for NinjaFlex. A copy has been posted at the end of this project.

Gotchas:

The next image shows what happens if the nozzle gets clogged.



Progress so far.



The real test will be in the near future.

 

Ran into a problem while printing with NinjaFlex. Not the filament itself, rather the printer gave me a "thermal runaway" error and promptly disconnected the main board from Octoprint (failed communications). Interesting!

So I upgraded the firmware and discovered the following:

1) it is possible to use the "non-Robo" firmware, however, doing this breaks the Z Offset wizard ( and possibly the other wizards ).

2) The latest Robo version of firmware works correctly.

From this fact finding mission, I conclude that non-Robo firmware is missing key bits (like sane parameters).

With newer Robo firmware, I will try printing the model in NinjaFlex again later.

 

Newer Update:

The problem with the thermal runaway error appears to have been solved with the firmware update. Trying another printing session with Ninjaflex.

 

Progress report:

So far so good. The model is around 50% finished using Ninjaflex TPU. I see some stringing, but not excessive.

 

Model at the finish of printing.



Model with most of the stringing removed

 

Some observations:

NinjaFlex filament adheres to the print bed almost too well. I reduced the print bed temperature to 30 C and still had a great difficulty removing the model. A high probability that NinjaFlex filament can be printed on the C2 printer without adhesion problems.

Comparing Sainsmart TPU filament to NinjaFlex 85A filament:

Models printed in both filaments can be flexible. Infill percentage for Sainsmart will need to be lower than NinjaFlex.

For the same print quality profile: Sainsmart TPU is more rigid than NinjaFlex TPU.

Stringing in models printed with Sainsmart TPU vs NinjaFlex TPU - better control of stringing with Sainsmart TPU

Neither filament is suitable for printing multiple models for a print job. Excessive stringing between models.

Conclusion:

Depending on the application and tolerance for string, the choice of using Sainsmart TPU vs NinjaFlex TPU remains with you. Models printed with NinjaFlex have a high tolerance for deformation (spongy feel to them). On the other hand, Sainsmart can be both flexible or rigid depending on the model's dimensions, print quality infill percentage and number of shells.

I have attached the Cura profiles as well as the Octoprint script used for this project