Stripping forever, filemant won't extrude, PLEASE HELP

[cb0 0]

Hello together,

I have continues problems with printing anything for over 2 weeks. :cry: I've tried a lot of things.

My setup:

Firmware: Marlin 0.9.3

GCode Software: Netfabb 4.8 and lately 4.9, also tried RepG GCode

Printing: usually ReplicatorG, also tried Printrun and lately Netfabb 4.9

Short problem description:

Filament won't extrude after first layers at normal speed when printing.

When feed by RepG (230°C,speed 2000) everything works fine.

Heres my detailed problem description:

First of all I thought my extruder gear won't grab the filament ending up in stripped filament.

So I tightened the filament feed mechanism and made sure the filament will be extruded towards the extrusion head.

This resulted in this: https://picasaweb.google.com/104195486315479086890/UMPictures#5723100012579085314 (short video)

The feed mechanism I not able to put enough pressure into feeding the filament to the heated head.

Then I opened the feed screw, heated the head to 230°C and tried to push the filament by hand. This is nearly impossible.

But if I heat it up to 230°C, and let RepG push the filament out at a speed of 2000, everything works fine.

It just seems to me that I'm not able to push out filament at a high speed.

When printing something, the first layer mostly looks real good.

But after the first layer, the head seems to stop extruding, the filament get's stripped and the print fails.

Example 1:

Example 2:

Another strange thing is that I cannot pull-out filament by hand when head is at 230°C.

This worked for me before and I also had some great quality prints. (e.g. http://www.thingiverse.com/marcusp/made)

Additional Infos:

GCode Header in Netfabb:

M92 E14

M106

M109

Temperature shown when printing in RepG: 185~195°C

Does anybody has any suggestion for me ? Maybe someone had this problem before.

Please Please help, I'm some kind of depressed.

[Daid 306]

How fast are you trying to print? And with what layer thickness? Maybe you are trying to print more then 10mm^3 per second, which seems to be about the limit of the current extruder.

[cb0 0]

I've tried the Standard and Ultra Settings from Netfabb.

Layersize: beween 0.150mm and 0.08mm

Speed: 60mm/s

This is the standard speed that netfabb has.

What values do you use ?

[joergen 2]

I've tried the Standard and Ultra Settings from Netfabb.

Layersize: beween 0.150mm and 0.08mm

Speed: 60mm/s

This is the standard speed that netfabb has.

What values do you use ?

I would first see what temp your PLA actually melts (manually pushing filament through the hotend and raising the temp by 5 deg until you can get it through easily, and then enter that temp into your netfabb print print profile: 185C is the lower margin for Ultimakers with perfect temp measuremnt, many UMs seem to differ by 10-15%, meaning you need to enter a higher temp to actually reach 185C in reality. the official melting temp for PLA is 208C, but it's soft enough for extrusion 25C below that.

[antiklesys 3]

I had a similar issue.

I resolved by changing the temperature in the material setting. I've cloned the PLA-Ultra profile and edited the temperature to make it be 210C to 220C. Works like a charm

Make sure the plastic is not too tight in the feeder. If it is then whenever it strips, it will make so that part of the filament stays on the screw which feeds it. This will reduce the capacity of the screw to feed the plastic.

I would also increase the temp to 250C in ReplicatorG and try to manually pull out the whole plastic. After that I would push it back in by hand trying to orient the curvature of the plastic to make it have the same one as the white pipe used to feed it. It will help reduce it's stress.

Also if you're using a raft you may reduce the raft printing speeds.

[devoney 0]

I am having the same issues as cb0. The filament gets stuck from time to time with rapid printing (low settings in Netfabb).

cb0 did a very good job at describing the problem.

Only for me the extruder does not set back like in the movieclip of cb0.

My setup is the same as cb0 (marlin, netfabb).

My problem occures even at temperatures set at 260ºC with PLA. I have not tried ABS extensively enough, so I am not sure whether I would run into the same problem with ABS. ABS is warping at my unheated bed, but thats another problem.

[IRobertI 521]

I don't know if this has anything to do with it but how much tension do you have on the tension screw? Looking at the first picture it looks like the filament is deformed quite a bit. Maybe try to back off on the tension a bit to see if it has an easier time going through the machine.

[devoney 0]

The tension of the screw is definitely the cause. Whenever I tighten it very fast, the filament deforms (a profile of the extruder nut) which causes so much resistance. It gets harder to pull back the filament when the print from the nut is very deep.

Not sure how to fix this though. Loosening the nut does not solve it because sometimes the nut does not grip the filament anymore.

Or maybe it is a very delicated balance....

I was thinking that multiple nuts, extruding: dividing the pressure on the filament while maintaining the same force of grip would be better.

What about lubricating the bowden cable (transparant cable where the filament runs through) with something like WD40?

[martijnvr 0]

I am a newbie in 3d printing and had similar problems in the first 2 weeks after building the Ultimaker. Printing simple objects was difficult at first, had to set the temp at high values, 250C to get a "normal" flow of PLA for extruder. Then sometimes the filament get stuck or the next day I spent a lot of time getting the PLA out of the extruder. My filament was also stripped and get stuck in the bowden cable.

In my struggle to get good results I changed the spool of black PLA with another one silver PLA. Then I noticed that the black PLA was soft and the silver one was hard. After this change the printing went well (low temp 185C), almost easy except of course from the normal "newbie" problems, calibration, settings, software issues.

In my case I was printing with soft-PLA and it was hard to get a normal print, is it possible that you are using soft PLA as well. I haven't had much luck printing good objects with this type of PLA and don't know what to do with it either.

[joergen 2]

The tension of the screw is definitely the cause. Whenever I tighten it very fast, the filament deforms (a profile of the extruder nut) which causes so much resistance. It gets harder to pull back the filament when the print from the nut is very deep.

Not sure how to fix this though. Loosening the nut does not solve it because sometimes the nut does not grip the filament anymore.

Or maybe it is a very delicated balance....

I was thinking that multiple nuts, extruding: dividing the pressure on the filament while maintaining the same force of grip would be better.

What about lubricating the bowden cable (transparant cable where the filament runs through) with something like WD40?

nooooo

the bowden is already made of teflon, and it doesn't get much slipper than that.

the tension screw needs to be set to "just enough" so you can't pull it back by hand when turning the extruder manually (about 5kg pull). see

http://db.tt/zVcKL9q0

(sorry for the large video, I haven't gotten around to edit and compress it)

if your filament is slipping, it means that you have another obstruction in the path. your filament needs to be able to go through without any hinderance:

http://db.tt/Ag7OpbbT

if your filament is still stripping, you are trying to extrude too much filament per second for your set temperature. try increasing your temp, or lower your speed.

[devoney 0]

@Joergen:

Videos are still loading... Might take a while I guess. Have not seem them yet.

I have checked and cleaned the PEEK. I could barely close the aluminium block onto the wood with the 4 screws (by hand), so I am absolutely sure the bowden cable touches the peek. The bowden cable is also cut straight.

What I have noticed is that whenever the filament starts slipping I can tighten the bold just a bit more. And then the filament extrudes for a while. But then again it start slipping some time later, and I tighten the bolt just a bit more. This can not go on forever, because in the end the bolt is so tight, it prints its teeth profile deep in the filament. Whenever I pull out the filament by hand I notice that the teeth profile causes much resistance. Whenever I shove in new filament (which has no teeth profile, yet) it slides in smootly.

I print with HIGH settings (meaning slow extrusion, compared to LOW) in Netfabb with 260º with PLA. But still the extruder jams.

[joergen 2]

I have checked and cleaned the PEEK. I could barely close the aluminium block onto the wood with the 4 screws (by hand), so I am absolutely sure the bowden cable touches the peek. The bowden cable is also cut straight.

Try chamfering the inside of the bowden a bit.... the idea is to prevent ANY contact of (molten) filament with the peek, under any circumstance:

viewtopic.php?f=7&t=102&p=339&hilit=bevel#p339

 

What I have noticed is that whenever the filament starts slipping I can tighten the bold just a bit more. And then the filament extrudes for a while. But then again it start slipping some time later, and I tighten the bolt just a bit more. This can not go on forever, because in the end the bolt is so tight, it prints its teeth profile deep in the filament. Whenever I pull out the filament by hand I notice that the teeth profile causes much resistance. Whenever I shove in new filament (which has no teeth profile, yet) it slides in smootly. I print with HIGH settings (meaning slow extrusion, compared to LOW) in Netfabb with 260º with PLA. But still the extruder jams.

you might be printing too hot, and the residual heat is creeping up the tube, and melts the PLA way before it hits the nozzle. the basic idea is to print as low temp as possible, within the ideal print temp window. the official melting temp for PLA is 208C, but it can be printed as low as 185C for very thin layers. you need to find the ideal printing temp for your UM first, and every UM is a bit different in terms of temp measurement (mine seems to be 25C or 10-12% off).

also, if you over-tighten the friction screw, you distort the filament, and a wide flat filament is easier to get stuck than a nice round one. in addition, the more tension you have, the less extrusion you get, because the teeth are sinking deeper into the filament, and the effective radius of the bolt shrinks, and you need more E steps to extrude 1mm filament.

[devoney 0]

Joergen, Those tips are well thought about.

Thank you so much. I am definitely going to follow those up.

I remember printing with default ULTRA ULTRA settings in Netfabb with a temperature of 185ºC. So lower the 260ºC sounds very logical indeed!

Edit:

Just disassembled my hot end. I guess this causes the trouble (notice the yellow filament in the bowden tube). or https://picasaweb.google.com/mikedeklerk/DropBox?authkey=Gv1sRgCIzMjuit25fY_QE#5725594259468292354

 

you might be printing too hot, and the residual heat is creeping up the tube, and melts the PLA way before it hits the nozzle.

Does this also imply that you should never leave on the heater too long (minutes?) while not printing?

Note:

I do not want to steel away this topic, but since this is all about extruding problems I thought: lets keep it in this topic.

[Daid 306]

 

Does this also imply that you should never leave on the heater too long (minutes?) while not printing?

Yes. Especially on higher temperatures. Or manually retract the filament so it cannot melt.