Ninja Flex TPE Filmament + EZStruder issues

[Channel83]

Has anyone successfully ran and printed with 1.75mm Ninja Flex TPE filament through their SeeMeCNC EZ Struder? I'm using a Printrbot J-head, but the EZ struder drive cant push the TPE filament through the nozzle, it just ends up slipping out below the hobbed gear eventually jamming the extruder drive. The furthest I've gotten is where the tip of the filament will reach the top of the J-head but the filament is not stiff enough for the drive to push down.

Any thoughts??

[mhackney]

I'm printing a spider in 1.75mm white right now. On my Max with EZStruder and SeeMeCNC hot end. This is my first attempt with NinjaFlex.

I am printing on glass (no heat) at 215°C .5mm nozzle. I am getting a lot of "popping" noises and the first layer had 1-2cm long gaps. Tried lowering the temp but that did not help. It is going to take some experimentation. I've seen some pretty cool things printed with it.

[Glacian22]

As far as I know, really springy filaments aren't recommended for use with bowden setups. Still, good to see people experimenting with it!

[mhackney]

The folks that make NinjaFlex say it is ok to use with a Bowden. I am getting much better results with just a little experimentation.

[Channel83]

I'm printing a spider in 1.75mm white right now. On my Max with EZStruder and SeeMeCNC hot end. This is my first attempt with NinjaFlex.

I am printing on glass (no heat) at 215°C .5mm nozzle. I am getting a lot of "popping" noises and the first layer had 1-2cm long gaps. Tried lowering the temp but that did not help. It is going to take some experimentation. I've seen some pretty cool things printed with it.

I see. However this is not resolving my issue. The issue is that I can't get my EzStruder to push the filament down into (and eventfully through) the hotend. The tip of the ninjaflex filament will get to the top of the hotend but the EzStruder cant push it down any further, then the filament starts come out below the hobbed bolt and ball-bearing wheel (because it's not rigid), then it jams.

[Batteau62]

Have you tried hand feeding/guiding the filament into the hot end until it extrudes? And then let the Ezstruder take over. I haven't tried flexible yet, but I would assume(like Michael says) lots of experimentation may be necessary. I would turn down all the extrusion settings in a slicer so the Ez doesn't try to push a lot of filament through. Things like-extrusion widths-make them the filament diameter, or even a little less. Kisslicer has a "Flow tweak" that might help with controlling material, etc.

[Channel83]

Have you tried hand feeding/guiding the filament into the hot end until it extrudes? And then let the Ezstruder take over. I haven't tried flexible yet, but I would assume(like Michael says) lots of experimentation may be necessary. I would turn down all the extrusion settings in a slicer so the Ez doesn't try to push a lot of filament through. Things like-extrusion widths-make them the filament diameter, or even a little less. Kisslicer has a "Flow tweak" that might help with controlling material, etc.

No I have not - Maybe I can force/push the filament down into the hotend with a small allen wrench first - then maybe I can rig it up inside of the Ezstruder. Hmmmmm.

And FYI - I'm not using Slicer and running an actual print job yet. Right now I'm manually turning on the extruder/hotend, setting a temp, and attempting to extrude the material first before I actually start a print job. I mean that sounds like the most practical thing to do first, correct?

Anyway this stuff is so soft that there's no way the Eztruder is pushing it into my hot end without some sort of manual adjustment. One user said he/she is using a SeeMeCNC hotend with the EZ-struder and was able to print (see posts above). Maybe I just have to get a new hotend? Right now I'm using a Printrbot hotend.

[mhackney]

Channel83, something is not right! Can we backup and try a few things to get going:

What size nozzle are you using? Try to use a larger (.4mm or larger) nozzle for these tests.

If you have some ABS, load it up and feed about 100mm through the hot end at 220°C in Repetier Host "extrude" button. This is just to make sure the path is free and clear.

Then while the hot end is hot, retract (using Repetier Host) about 20mm to pull the ABS out of the hot end. Then remove the ABS and load the NinjaFlex like this:

Get the NinjaFlex started in the EZStruder then use the extrude button to feed it up through the Bowden to the hot end - which make sure it is 220°C. Watch carefully as the filament reaches the hot end and move in 10mm increments. As it gets close, the filament should start to push the remaining ABS in the nozzle out. Does this happen? Or is it getting caught up at the top of the hot end as you describe in your first post. If it's getting caught up, did the ABS seem to snag there too? Have you checked that the PTFE tube and path through the hot end are clear and not binding?

Continue and see if you can get the NinjaFlex to start to extrude. Does it or do you get the EZStruder jamming?

I was not able to get my EZStruder to eject the NinjaFlex as you describe even when I physically blocked the nozzle so nothing could extrude. Instead, I get skipped stepper steps and chewed up NinjaFlex.

Hope this helps.

[Batteau62]

Yes, I think using the host to get things started before a print job is a good idea. I would do the hand feeding/guiding into the hot end. I don't think it's a hot end issue, although having choices is good. I have a Printrbot jr. and as long as the temps are good? it preforms well. What size nozzle opening are you using? .5mm? That would be the smallest I would try. I think hand feeding could allow you to fine tune the temp too. IMO(and as you've found) this stuff is not going to like being forced through the bowden tube. Finding that perfect extruder force to extrusion temp is going to be critical. I'm ordering some of this, so I'll be able to check back and give my experience with it.
-mhackney is great resource, hopefully he'll chime in with his observations

edit-I think I pushed the "submit" button the same time Michael did!

[Channel83]

Channel83, something is not right! Can we backup and try a few things to get going:

What size nozzle are you using? Try to use a larger (.4mm or larger) nozzle for these tests.

If you have some ABS, load it up and feed about 100mm through the hot end at 220°C in Repetier Host "extrude" button. This is just to make sure the path is free and clear.

Then while the hot end is hot, retract (using Repetier Host) about 20mm to pull the ABS out of the hot end. Then remove the ABS and load the NinjaFlex like this:

Get the NinjaFlex started in the EZStruder then use the extrude button to feed it up through the Bowden to the hot end - which make sure it is 220°C. Watch carefully as the filament reaches the hot end and move in 10mm increments. As it gets close, the filament should start to push the remaining ABS in the nozzle out. Does this happen? Or is it getting caught up at the top of the hot end as you describe in your first post. If it's getting caught up, did the ABS seem to snag there too? Have you checked that the PTFE tube and path through the hot end are clear and not binding?

Continue and see if you can get the NinjaFlex to start to extrude. Does it or do you get the EZStruder jamming?

I was not able to get my EZStruder to eject the NinjaFlex as you describe even when I physically blocked the nozzle so nothing could extrude. Instead, I get skipped stepper steps and chewed up NinjaFlex.

Hope this helps.

Mhackney, thank you for all of your observations, to address what you've detailed:

-I'm currently using this hotend/nozzle (.4mm):

https://printrbot.com/shop/1-75mm-ubis-ceramic-hot-end/

I'll definitely try unloading 100mm of ABS at 220c then attempt running the Ninjaflex through at the same temp at 10mm increments.

I need some clarification on the following: "Have you checked that the PTFE tube and path through the hot end are clear and not binding?"

How do I check that? I don't see or have any PTFE tubing rigged between my hotend and the EZStruder drive - there's really not enough space between the two. The path your speaking about must be the channels right through the EZStruder to the top entrance hole of hotend itself? I know my Extruder/hotend setup has no problems extruding PLA or ABS - so the path must be clear, right?

I will try out these strategies soon and will update everyone with the results.

Thanks again, fingers crossed.

[mhackney]

Clarification - that was assuming you were using the stock SeeMeCNC hot end, sorry I didn't pay attention that your hot end may not have PTFE!

On the J-head, SeeMe extruders, there is a short length of PTFE inside the hot end that runs down into the nozzle.

The path may be "clear" but if there is even a slight burr or constriction, the NinjaFlex might get hung up whereas PLA and ABS might not.

thanks and good luck!

[Channel83]

Clarification - that was assuming you were using the stock SeeMeCNC hot end, sorry I didn't pay attention that your hot end may not have PTFE!

On the J-head, SeeMe extruders, there is a short length of PTFE inside the hot end that runs down into the nozzle.

The path may be "clear" but if there is even a slight burr or constriction, the NinjaFlex might get hung up whereas PLA and ABS might not.

thanks and good luck!

I see. And in the event if there is an un-perceivable burr or constriction, what should one do?

[mhackney]

Fix it! It depends on where the burr is but you can trim it with a sharp hobby knife if you can reach it, or chase it with a sharp drill. Let's find out if there is a problem and we can go from there. It might just be a slight misalignment.

[Channel83]

Updates, but not extruding yet.

I got the hotend up to 220C and extruded 100mm of abs as suggested and retracted 20mm to remove the ABS.

Then I fed the Ninjaflex down into the EzStruder. The tip of the Ninjaflex makes it to the top of the hotend (maybe getting inside a few mm) then it starts binding up and jamming at the EzStruder still.

[img]http://i.imgur.com/qLDVpR1.jpg[/img]

[mhackney]

Ok, that really sounds like you have some sort of path blocking issue.

Try this, pull the NinjaFlex out until you can see the end plus about 1" of space above the hot end. Then, manually push the NinjaFlex into the extruder and try to feel if/where/how it is getting hung up. If you feel a hangup, remove the connector for the Bowden tube from the top of the hot end and do the same, but now you can see the filament coming out the other side (hopefully).

It just seems there has to be a blockage there somewhere. You should not have a problem pushing the filament when it isn't even getting to the hot end.

[Channel83]

I don't have a Bowden tube, also there is not a visible 1" space between the ezstruder and the top of my J-head, there is only a couple of centimeters between the top of the J-head and the bottom of the ezstruder. Im taking off the front black faceplate of the Eztruder and going to try and manually push the Ninjaflex through now.

[mhackney]

What printer are you using? I assumed you had a rostock or orion with a Bowden. That explains why the red release lever is at the top of your photo! Maybe take a picture of your ezstrude-hot end set up. I still think there is an alignment problem or something is snagging the filament at the top of the hot end.

[Channel83]

Ordbot Hadron.

I think I'm getting it, the ninjaflex, to drive through. I just got a nasty little burn on my hand from the hot-end. Updates soon.

[Channel83]

Success!

So, I took the J-head entirely off of the Eztruder and gently pushed all of the ABS out with an allen wrench while still heated up. So, it could have been an obstruction in the J-head or, which I hope is not the case, I have to do this every-time I wanna load Ninjaflex into the J-head, thus manually doing it by hand, then letting the EzStruder do the rest:

[img]http://i.imgur.com/GbnbOSil.jpg[/img]

[mhackney]

Interesting. I suggested using ABS because it has a melt temp in line with NinjaFlex. I've been printing a lot of PLA recently and have flushed my hot end of PLA by pushing the NonjaFlex through it. Basically, I start with the hot end at 190°C (my normal PLA temp) and then set the temp to 220°C. As the hot end heats up, I push the PLA out with the NinjaFlex using the ezstruder. Perhaps the lower viscosity of PLA at that temp makes it easier to flush out than ABS? Just a thought as to why I didn't experience this.

[singh336]

Sorry for the bump

but wanted to add.. i had the same issue going from ABS to ninjaflex last night..


what I did was manually push the filament into the hot end for a while... I probably manually pushed over 100mm of ninjaflex into the hot end to flush out the abs.. it was black (black abs) for a while and eventually I started to see the red ninjaflex come through..

the abs is just too stiff for the ninjaflex to push out i guess.. even when melted.

i've gotten it to print but I can't stop the stuff from tangling up near the hobbed gear even after a bunch of small modifications in that area.

i think this stuff is not for the rostock.