Filament no more extrude

[sam 0]

Hi all,

I got a serious problem. After about 1 hour++ printing, the filament stops extruding while the machine still printing. I'm using slic3r, RepG software. Any advise? Thank you in advance.

[Daid 306]

Is the extruder gear still turning or not?

[sam 0]

Yes sir, it still turning as usual. Got no problem if the print time less than 1hour, but if exceed, about 1 hour 15min, this will happen. I tried to slow down the feed rate and increase the temperature hoping that it will extrude soon, but still negative. :(

[Daid 306]

Could be that the filament is grinded down (a hole was cut in the filament by the extruder drive).

It can also be that the gear is turning but the bolt is not, but that's rare and should cause a lot more problems. (still easy to check)

If it's grinding, then you could have a bit too much pressure on your filament (by the tension knob), you can also have filament with varying diameter (thick or thin sections that cause the problem)

[sam 0]

I'll try to check with the first option. Was thought if it's grinding too, not check it yet. Thank you sir!

[polymorph 1]

What did you find out? Did you solve the problem? Have you been cleaning out the knurling on the drive bolt regularly? Get a stiff steel wire brush and scrub it out.

I have found it is a very fine line between too tight and not tight enough on the feeder. Too tight, it grinds into the plastic pressure plate too hard and the teeth in the bolt grind a flat in the filament. Too loose, it also grinds a flat in the filament. Once it starts grinding, it fills the knurling and it is more likely to slip and grind in again.

Unfortunately, as filament diameter changes, the screw settings must change. But it'll stay stuck on the flat part ground out unless you also push the filament in -really- hard while it is feeding, for long enough to get past the flat spot.

I printed an upgrade that replaces the plastic pressure plate with one that includes a ball bearing. However, the same problem is there - no spring pressure, so even slight changes in filament diameter mess it up. The ball bearing just allows you to set the pressure even higher. But I'm an hour into a 2.5 hour print job, I don't want to quit and start over, so I'm riding herd on it.

The "knurling" on the bolt is just too sharp. It tends to grind into the filament. Then if you don't immediately clean out the knurling, it begins slipping and grinding much more often. As far as variations, I'm still using the roll of white that shipped with my Ultimaker.

I also think having only one point of contact with the drive to the filament is a problem. A lot of stress on the plastic right there. I like the half-round non-sharp feeder wheel someone was making. But I think rather than a non-drive wheel pressing the filament into it, I'd like to see -two- drive wheels pressed together.

In fact, I'd like to see a drive with four wheels - two sets of two drive wheels. Perhaps the first drive wheels have a clutch and attempt to spin a little faster. Or just a DC drive motor, the amount of current regulated to set up a pre-tension pushing the filament into the stepper-driven drive wheels. Like what happens when I grab the filament and push it into the feeder mechanism.

[tomnagel 126]

The best option I have found for the feeder is called the "Bertho's feeder upgrade". You can print some of the parts you need, other have to be found in a hardware store.

This upgrade, and others, are mention on http://forum.ultimaker.com/viewtopic.php?f=6&t=1368#p8325

Bertho's feeder upgrade changes the delrin pressure plate of the UM feeder with a ball bearing, and it gives pressure via a spring. I'm building it right now, because I think that is a major improvement.

[fluxline 0]

There is also chopmeister's, it had a few more features I prefered over bertho's great design, I think chopmeister used the concept in his design. I'm also just putting it together so I know in a bit ...

http://www.thingiverse.com/thing:27626

[sam 0]

What did you find out? Did you solve the problem? Have you been cleaning out the knurling on the drive bolt regularly? Get a stiff steel wire brush and scrub it out.

U're right, found out the bolt already grinded the filament, so what I did is I pull out the filament, get rid of the exhausted filament part, and put it back in. I also clean back the bolt and scrubbed out the remaining filament at the bolt. Now its work fine.

[yzorg 9]

ABS Problem with the Feeder Upgrade.

Natural white ABS, 260°C.

I now have the new springload feeder part, which i thought would reduce my problem of always skipping feed.

But with it i cant print at all. it looks like thers not enough pressure.. (becaus i tried by raising from lowest pressure)

the max. position of the ball bearing wheel is not enough.

i experience a worse extrusion quality than ever before...

Even with maximum sping pressure It runs only for about 1cm then extrusion gets thinner and thinner and stalls.

[joergen 2]

ABS Problem with the Feeder Upgrade.

Natural white ABS, 260°C.

I now have the new springload feeder part, which i thought would reduce my problem of always skipping feed.

But with it i cant print at all. it looks like thers not enough pressure.. (becaus i tried by raising from lowest pressure)

the max. position of the ball bearing wheel is not enough.

i experience a worse extrusion quality than ever before...

Even with maximum sping pressure It runs only for about 1cm then extrusion gets thinner and thinner and stalls.

are you sure you have a clear and easy pathway for the filament through the bowden into the hot end? if there are any obstructions along the way, even the best filament transport mechanism will fail. i would suggest to look for problems "further down the road" first.

[yzorg 9]

the filament path is clear and by hand the filament is easy to extrude..

i also noticed that changing that Value "Flow" on the Ulticontroller seems to have no effect.

I tried to adjust there to find my maximum extrusion speed settings. nothing changes while printing.

changing the speed works. after some seconds it will speed up or slow down.

[yzorg 9]

i could fix it now..

Problem was the forming of "Retractionplugs" just above the hotend. See the other thread viewtopic.php?f=7&t=1958

these plugs would jam incoming filament with increasign strengh where the Bowden and the PEEK meet.

I noticed with my V1 nozzle it tends to clog less. so this is my solution for now...

I removed the V2 Nozzle and the White insulator part. because before i added them i was able to print very good with my settings. not that much depending on filament softness and diameter.

[snowygrouch 1]

I maintain that for 100% reliability a form of active cooling for the printhead hotend is essential.

Honestly it makes me crazy seeing still loads of people getting clogged hotends and all sorts of issues, when

simply putting an €8 fan on the head, plus one tiny printed airduct will completely 100% solve any problems

even with a V1 nozzle.

[IRobertI 521]

But even with cooling you could still have the bowden pop out due to pressure and then you're right back at the plug again. Bowden popping has been by far the biggest issue I've had with the machine.

[snowygrouch 1]

well all I can say, is that I have never had a bowden pop out even once.

The reason for this, as best I can contrive - is that because my hotend never has any plugs forming, or even

any "buildup" further up due to retration - its always incredibly easy to push the filament though (so I also

never even once stripped the filament since cooling the hotend...interesting...).

So I never build up any pressure in the bowden tube, because the only reason to get extra pressure is when

less comes out one end..than you put in the other. When I had problems before cooling the hotend, I would often notice that it was getting almost impossible to push through the filament by hand, when trying to sort out plugs.

So fix the hotend plugging, and you will also pretty much cure bowden pops.

Perhaps if you like to print at obscene speeds you might increase the strain on the bowden, or if you are using a

0.25mm or 0.3mm nozzle...but with active cooled hotend and standard nozzle diameter. I have never popped a bowden OR had a plug.

Either that or its all an amazing co-incidence that after fitting it my machine never breaks down anymore ?

Or I have some sort of "magic-ultimaker" that somehow has a better bowden clamp.

I am using and have always used the standard V1 hotend, and the original bowden clip. Not even the newer better one.

Im not trying to "brag" or something, im just saying, that THIS is what I did...and afterwards it never ever broke again. Thats all !

Regards

C.