Having tons of issues with Ninjaflex - anyone have any luck?

[singh336]

Hey,


I tried to search the forums for anything related to ninjaflex and haven't found much other than the one thread with the small extruder mod to feed ninjaflex a bit easier.

I see he was able to print at 50mms, I'm not even sure how that is possible.


I did the same mod and a few more to try and deal with issues I'm having.

The biggest problem is that filament will jam in the extruder often. Sometimes it slips behind the bearing that pinches it against the extruder motor gear.

I just want to know if anyone has tried it and had any luck? I just can't see it working well with just that one mod posted in the thread.

I understand its best to use the filament with a printer that has an extruder near the print head but I thought it was possible to print with the rostock max v2 as well ?

Thanks for any tips / help.

I'm printing it at 228-230C and 40C bed temp.


I think maybe backing down the retraction speed and travel speed might help a bit ?

[DavidF]

Somewhere on the forum there is a post for modifying the extruder so that the bowden tube runs all the way up to the hobbed gear. That's the best mod one can make in my opinion.

[singh336]

Hi,


Yes I think you are talking about this thread

http://forum.seemecnc.com/viewtopic.php ... lex#p43832


I have done that with the tube right up to the gear and then after I found it having other issues I made other mods to the extruder to keep the filament straight, provide more pinching pressure on it etc.


So far its working better but here and there it will jam up under the hobbed gear right before the tube.. which I can't believe because the tube is right up against the gear.

15mms is what i'm trying to run it at. I'll see if I can post some pics.

[singh336]

Trying to post more than one picture per post ?

[singh336]

Anyways don't mind the ghetto rigged temporary fixes like the paper stuffed in random places and scrap filament shoved into the extruder LOL.

I started out with just the single mod talked about in the thread linked above. That didn't work so I did a few more things to solve more problems and now my latest problem can be seen in these pics.


This is killing me...


Should I buy a different extruder?

[singh336]

[img]http://upload.vstanced.com/images/2014/ ... 6775_n.jpg[/img]
[img]http://upload.vstanced.com/images/2014/ ... 2797_n.jpg[/img]
[img]http://upload.vstanced.com/images/2014/ ... 7615_n.jpg[/img]
[img]http://upload.vstanced.com/images/2014/ ... 7245_n.jpg[/img]


went for a different cut on the tubing.. its better but still jams up

[Nylocke]

Looks like you don't quite have the tube right up against the gear, perhaps if you get the tube a bit closer it will work even better. Also you seem to be over tensioning the filament with that paper spacing, you might be squishing it (and since the motor/gear gets hot, it gets softer) to the point where it is thin enough to squeeze out of the path.

[singh336]

thanks for your reply,

i'll take the paper out and see if that helps.

I put pla in the machine right now because im going to try to design my own extruder or try to modify one available on thingiverse that is made to go right up against the hobbed gear.

not sure if its something you can see in my pictures but the tube was actually up against the gear and idler, i couldn't believe how close i got them, they were actually rubbing but it didn't affect the drive gear so i left it rubbing.

somehow it STILL buckled like that which really surprised me.


it doesn't do it during normal extrusion speeds but 1/4 or 1/2 through the print it will do it definitely.

[Nylocke]

I was looking at the first picture, didn't notice your finger pressing the lever down. I looked at the 3rd picture and I see how close the tube is now. What speed are you running at? I think the recommended normal speed is around 10-20mm/sec, I know its slow but maybe start there (if you aren't already there). Do you have the stock hotend that came with your printer? What retract settings are you using?

Also, what slicer are you using? I've observed Cura 30mm/sec to be faster than Slic3r 30mm/sec. There also is another take on the EZstruder http://forum.seemecnc.com/viewtopic.php?f=35&t=6271 by Glacian22, to solve some PLA issues. Might help with your issues?

[singh336]

Hey, thanks for your reply.


So yes my printer was 100% stock including the hot end, extruder etc.

I went searching around on thingiverse and found a custom extruder that was made to handle flex materials like the ninjaflex stuff.


I did this late last night and didn't have the ability to go grab new hardware and do thnigs the right way.

[img]http://upload.vstanced.com/images/2014/ ... 6009_n.jpg[/img]

You see here how close it will come to the hobbed gear, nearly rubbing it.
[img]http://upload.vstanced.com/images/2014/ ... 2860_n.jpg[/img]
here is a temporary but very effective solution to stop the filament from slipping behind the idler
[img]http://upload.vstanced.com/images/2014/ ... 2691_n.jpg[/img]
Now on here you can see i'm still using the original lower piece here which I plan to completely replace and have the connector brass fitting thread directly into the new extruder assembly. but for now you can see i used some tubing to get right up into the blue pla so the filament cannot buckle there between the pieces
[img]http://upload.vstanced.com/images/2014/ ... 2612_n.jpg[/img]

So after 4 hours overnight the print was a success (just a test print for an iphone 5C case for my gf, nothing crazy but a good test.)
[img]http://upload.vstanced.com/images/2014/ ... 6615_n.jpg[/img]
[img]http://upload.vstanced.com/images/2014/ ... 1199_n.jpg[/img]

[img]http://upload.vstanced.com/images/2014/ ... 2488_n.jpg[/img]

Obviously not using any support material affected the print quality at the bridges over all its a bit stringy but im amazed mostly that it did not jam up in over 4 hours of printing. It was jamming up in about 10 mins or less before.


The speeds im running and have always ran was 15mms and this print used no retraction which i believe is a source of the jamming issues.

[Nylocke]

Good to see that you had success. Maybe try adding in retraction and see what happens? Unless it doesn't bother you

[singh336]

I think what i'll do now is work on making a custom model to print for the extruder using this idea , so it doesnt have to be "hacked together" like.

I'll try to use as much factory hardware as possible so there isnt anything special to buy incase anybody else wants to print this out and use it, i really can't believe the old extruder tube mod worked for anyone let alone 50mms.

[singh336]

having good success so far...


made my own custom extruder base and after a little bit of dremel work i was able to get it working today and it was very smooth. i was able to extrude ninjaflex that i had a 30mms profile for at 75% speed... it still buckled up at 100% 30mms so im now printing a revision of my extruder to hopefully stiffen up support and get it closer to the idler bearing....

i also made some other changes like the angle of the spring plate and some other stuff... the brass fitting that connects the tubing is threaded directly into this plate eliminating the entire black abs lower half of the original mount / extruder.

[singh336]

new extruder thread here

http://forum.seemecnc.com/viewtopic.php?f=35&t=6461


working very very well.