Ninjaflex printing issue. Still not solved :)

[dunginhawk]

Good morning gents.... I have a new feeder set up and appears to be working well.
However when i try ninjaflex here is what i get.
[img]http://i1132.photobucket.com/albums/m562/dunginhawk/B33A32B4-20E0-4230-9DAE-A4CB01CD8238_zpsfw1iquh8.jpg[/img]


I ran some cleaning filament through the hot end.
im running at 240c at 15mm/sec.

any advice?

thanks

[BenTheRighteous]

What's your first layer height?

When I tried printing soft pla, I tried printing 0.1mm layers. That worked, but I had to keep my first layer as 0.2mm or else it wouldn't fly.

[dunginhawk]

layer height is .3. ill try .1

[mhackney]

We need more information! What slicer are you using? What slicing parameters? Especially retract settings, this looks similar to issues I had when retract was too high. Layer height, nozzle diameter? What hot end are you using - stock or what aftermarket?

[BenTheRighteous]

Also what bed adhesion method are you using?

[dunginhawk]

stock hot end.
no retraction
.1 layer height
matterslice

bed adhesion is elmers purple glue.. its sticking quite well.



so i changed it to .1 here is the result...
its defintely under extruding. so maybe i need to up the multiplier.
ill keep tinkering, but any other thoughts? really thin lines here, not thick like pla or abs for me.
thanks
[img]http://i1132.photobucket.com/albums/m562/dunginhawk/52C83178-40FA-4A0B-B8E0-D85B1C923EFC_zpslhpiszpy.jpg[/img]

[mhackney]

It may also be an extruder issue if the extruder is not getting a good enough grip. Have you tested extrusion into air and measure the amount moved when you tell it to extrude 10mm?

[mhackney]

I have another thought...
Ninaflex is tricky with a Bowden setup. I know a few of us are successful but I am using a E3D Kraken or V5 hot end. These hotness come with their own Bowden tube which looks different than the stock tube. The NinjaFlex product page does say that a PTFE tube reduces friction. I wonder if the E3D tubes are actually PTFE and perhaps the SeeMeCNC tubes are not or a different formulation.

[dunginhawk]

ok. so the only change i made was to increase the extrusion multiplier to 2, from 1.
and increased the layer height to .2

[img]http://i1132.photobucket.com/albums/m562/dunginhawk/885B229E-A104-4385-A33D-593F2D0A4CE4_zpsqvohrofh.jpg[/img]

[dunginhawk]

yep. ive been working on the extrusion from the feeder all morning... Im using an airtripper extruder now... so the tension is pretty good. i think the feeding is actually very dialed in.
by the looks of my last print, i could set the extrusion multiplier to 5... that just seems insane though.

[mhackney]

This is a bit of a PIA but would give some good insight...

Extrude 10mm and measure the length of filament coming out of the nozzle. Pay attention to if it keeps extruding out for some time after the extruder stops pushing - that gives some indication of back pressure.

Then, swap over to PLA or ABS and do the same test. The length of the extruded filament should be very nearly the same. If it isn't then you have an extrusion problem. I'm betting its the friction in the Bowden as per my previous post. Do you hear skipped steps?

[BenTheRighteous]

If you think the friction of the bowden tube is to blame, you can try coating the first meter or so of filament with canola oil.

Also, tell us more about this cleaning filament you used. What temperature are you supposed to run it at? Do you think some of it is left over inside your nozzle and clogging things up, because 240 isn't hot enough to melt it?

[dunginhawk]

so the cleaning filament will work at basically any temperature.. it works REALLY well... you can see all sorts of stuff stuck inside the filament when it extrudes.. im pretty confident it works well.
I will try a couple of these suggestions and see what i come up with.
thanks

[dunginhawk]

ok, so the ninjaflex is building up a lot of back pressure.
once it was primed, 10mm extruded a lot of filament for up to minute afterwards... it thinned out of course after a while.

with ABS, a 10mm extrusion got me about 30mm of filament with very little pressure behind it... it oozed for a few seconds, then stopped

[dunginhawk]

with the oil coated filament,it wont even extrude.. the gear just slips on it

[mhackney]

BenTheRightous' suggestion to apply a little canola oil (very little) to the filament to reduce friction is worth trying. Also, you may have seen my rather looking thread here about the E3D nozzle bore length issue I discovered earlier this year. I have a specially modified nozzle for ninjafex that has a .5mm long bore. This greatly reduces the amount of back pressure. I can use the normal 1mm long bores too with the E3D Bowdens (which probably are PTFE) but the shorter bore gives even better/more consistent results. This idea of reducing the bore length is applicable to almost any nozzle and can be used for special materials like ninjaflex and the new copper, bronze and brass metal filled filaments from colorFABB (which I have jetting to me as I type). The more viscous the material the bigger difference a short nozzle bore will make.

[dunginhawk]

well ill be darn
[img]http://i1132.photobucket.com/albums/m562/dunginhawk/D7099106-4B63-45D3-A718-C68CE434D890_zps5s2kiiai.jpg[/img]


first layer extrusion width moved from 200% to 100%

[dunginhawk]

also, i have printed copperfil to perfection with the new feeder. so im hoping to get all my settings dialed in for each filament
i may try a full print at these settings to see how it goes.

[dunginhawk]

so here is a small finished test print... came out really good for a first print.
[img]http://i1132.photobucket.com/albums/m562/dunginhawk/84432CD0-FF84-4E35-9D7F-635DC15F2635_zpsrl1no7y2.jpg[/img]

[mhackney]

Great, you should share what you did so people can learn from it!

[dunginhawk]

Will do...

1. I have a new feeder. http://www.thingiverse.com/thing:126778 I found too much jamming and stuff with softer filaments on the stock feeder... Even with the PTFE tube in there.
However, even on the airtripper i found some jamming as well. So I had to drill out a hole for ptfe tubing there too... Now it seems to be running pretty well.

Settings.

.2 layer height
15mm/s print speed
I ran 4 times around with the skirt to make sure the extrusion was good.
Changed first layer extrusion width from my base 200% to 100%.
Cooling on after 2nd layer 100% (i run three layer fans)
Extrusion multiplier of 5 (i really dont think that setting does anything though)
Temp - 240c
Bed - 40c.
VERY good adhesion with the purple glue
0 retraction.

Im printing a case for iphone 6, ill post that when im done.. providing it turns out.

[dunginhawk]

this is such an enigma... after a successful print, i tried an iphone case with ninjaflex and it got the first three layers PERFECT. then there was either a jam in the nozzle causing the feeder to slip, or the feeder just slipped.
of course it stopped extruding and i stopped it.
unreal.

should i just give up on soft filaments on the rostock and buy a different printer just for soft filaments? seems like a waste, but its just so frustrating

[BenTheRighteous]

Have you tried cooling the stepper? When I tried printing with soft filament, it would work for awhile before jamming. Pointing an 80mm fan at the extruder stepper fixed the problem.

[dunginhawk]

im about to try that. i have a big fan blowing on it, which is cooling it... now for some reason my z height is off... when i go to calibrate it, i set it right. then run the towers gcode (that guanu gave me), and the nozzle ends up like 10mm from the bed. its freaking bizarre.

[dunginhawk]

ok.. .so a couple things...
1. i recalibrated after some strange behavior last night... things are good now.
2. Re-trying the iphone case again with slight modifications.

What im noticing is this. - [img]http://i1132.photobucket.com/albums/m562/dunginhawk/th_1A91D3DA-07F8-40DF-BB0A-8F0297AFE254_zpsg8738b4s.mp4[/img] as you can see the black mark is moving, then stopping, then moving again.. but the entire time the drive gear is continuing to move... would this be some setting i am missing? perhaps the extrusion multiplier?

Also, i think part of my problem MAY be the spool of ninjaflex itself.. its wrapped in such a way where the filament often gets wedged between other layers on the spool and it requires more force than usual on the drive gear to pull that loose. With the TINY variances with soft filaments causing major differences, its a thought.

One other thing im trying is a fan on the stepper motor... Its cool as the other side of the pillow now. It certainly cant hurt. Thanks Ben

Last thing im trying is i am running the tensioner for my feeder at its loosest setting possible. just enough to contact the filament with the bearing, but not enough to make anything work that hard.

oh and one more thing. I cut a little length off the PTFE tube in the feeder to allow more contact with the gear.

Ill certainly keep everyone posted on my results.