Always failed to print Ninjaflex with my UM3, HELP!!!!!

[xiaomage 0]

I started to use Ninjaflex to print some products, but none of them is successfully printed. The filament will stop extrusion halfway through the printing process. 

This is the latest result:

 

 

[xiaomage 0]

The setting:

print temperature: 240

print speed: 20

flow rate: 120%

retraction is disabled

 

[Smithy 1,144]

Have you checked the filament when doing an unload? I assume that the pressure is too high in the feeder and the filament too soft. Additionally the friction in the Bowden tube is much higher than with normal material. I read somewhere that someone put a drop of oil in the tube to reduce friction, but I am not sure if this is really a good idea.

 

I have only experience with TPU from Ultimaker, worked fine, but is harder as Ninjaflex.

[93sugar 0]

I was told by support from the company I bought my UM3 that Ninjaflex isn't compatible with the UM3.  But I don't think that necessarily means that it won't work with the proper settings.  I tried with similar settings that you posted and my print failed as well.  The feeder ground the Ninjaflex filament and I had to open the feeder up to remove the filament.  I wonder if the flow rate is set lower would make a difference.  Probably even using a larger nozzle.  Maybe flow rate at 80% and using a .8mm nozzle.  I just got my UM3 cleaned up and back together so I'm hesitant to try it again right now.

[geert_2 557]

I have no experience with flexible materials, so can't really help.

 

But what if you disconnect the bowden tube at both ends, and manually try to push this filament through? And then reconnect it at the nozzle-end, heat up the nozzle, and try again, thus manually pushing from the back? Also, manually feed filament directly into the nozzle while it is hot. Maybe these tests might give you an indication and a feel for the amount of friction and resistance?