Can't extrude properly

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RipleyLlessur
Posts: 11
Joined: Sun Jul 17, 2016 12:31 am

Can't extrude properly

Post by RipleyLlessur » Thu Aug 11, 2016 6:33 am

Hi all, I've been having trouble extruding recently. Using M2 VE and PLA. I thought the problem was a well-used nozzle, so I just bought some replacements, but it hasn't been solved. Nozzle will get hot but not push filament out, except for a small burst when the new lead makes contact. If I push the filament a little I can get some through, but it won't continue. I have taken the head apart a few times and cleaned everything, cleared the hot end, replaced the nozzle. I have tried a bunch of filament tensions, and when looking with a flashlight, the toothed gear is making good contact and spinning. The smooth wheel in the filament drive (V4) isn't freely spinning; should it be? Or is it possible that the inside of the hot end isn't getting hot enough to melt? I've tried 200-210 C. I'm just using PLA, and I've tried 3 diff spools.
And, while trying to fix it, I think a PLA hair dropped into the electronics case through the fan. Whats the easiest way inside of there?
Thanks!!

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Jules
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Joined: Wed Jan 21, 2015 1:36 am

Re: Can't extrude properly

Post by Jules » Thu Aug 11, 2016 3:55 pm

The most likely culprit for causing the extrusion to stop is the Filament Drive Screw tension has gotten a little too loose from machine vibrations. Check the tension using the guide here:

Filament Drive Tension viewtopic.php?f=3&t=2694

The electonics case has 3 screws on the right side of the machine. Loosen those and swing it up - SLOWLY. The fan wires and other wires will still be attached. so be careful.

RipleyLlessur
Posts: 11
Joined: Sun Jul 17, 2016 12:31 am

Re: Can't extrude properly

Post by RipleyLlessur » Fri Aug 12, 2016 5:29 pm

Thanks Jules. I have been trying different settings on the filament drive tension screw and it hasn't worked. I can see that the gear is making solid contact with the filament, and my tooth marks are about the right size. The smooth wheel doesn't seem to spin freely; should it spin or be mostly static?

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Jules
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Re: Can't extrude properly

Post by Jules » Fri Aug 12, 2016 5:44 pm

It should turn freely. It might be a bit too snug or jammed in some way. That would be something to look into.

One thing that might help....you can remove the whole fan assembly by removing a couple of screws, and just let that hang down next to the side by the wires, or set it up on the X-gantry. (You don't need to disconnect the wires.) There should be one screw that attaches both fans to the filament drive - that's the one to loosen. (Sorry, I've got a dual now and it uses 2 screws.)

But that will let you see inside the filament drive, and you can watch what happens when you use the jog controls to feed the filament in just a little. Might spot a problem like shredded filament or jamming as it tries to feed into the hot end. Be careful not to let the wires contact the hot nozzle while you're doing it, and make sure to not move the print head left and right by hitting the wrong jog controls.

RipleyLlessur
Posts: 11
Joined: Sun Jul 17, 2016 12:31 am

Re: Can't extrude properly

Post by RipleyLlessur » Sat Aug 13, 2016 3:37 am

I loosened the smooth wheel so it can spin easier, but that didn't solve the problem. Then I removed the wheel and cleaned it, but it wasn't so dirty or jammed anywhere. I've tried a bunch of tension settings and that doesn't seem to affect the problem. If I remove the hot end the filament will feed easily. I think the problem must be in the hot end itself? I've cleared it several times and the nozzle is brand new. Is it possible that there is an issue inside of the hot end? The outside seems to heat up just fine. But could the inside be staying cool? When I retract the filament, only the very end (inside the nozzle) is melted. When I feed new filament through I get a burst and maybe a bit beyond that, but then it stops. :?
Also, I opened the fan case and cleared the obstruction, thanks!!

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Jules
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Re: Can't extrude properly

Post by Jules » Sat Aug 13, 2016 3:48 am

When you retract the filament completely, usually the only part that is melted is the very end. so that's okay and expected.

You shouldn't push down on the filament to try to feed it in though - that can cause jamming. (Were you not able to feed the filament through again after you cleaned out the jam? Using the jog controls, and after cutting a flat end on the filament to feed it in?)

Wait a minute....how many millimeters are you feeding through using the jog controls? 10 mm? 20 mm?

If you are only feeding in 10 mm of filament, you will see a short burst of filament and then just a little drool. If you feed another 10mm in, you get another burst.

RipleyLlessur
Posts: 11
Joined: Sun Jul 17, 2016 12:31 am

Re: Can't extrude properly

Post by RipleyLlessur » Sun Aug 14, 2016 6:03 pm

The filament feeds fine until it hits the nozzle. When I put a fresh piece of filament through, when it first contacts the nozzle I'll get a burst, but after that, when I feed filament nothing or very little will come out. Obviously I am only expecting filament to come out when I am feeding more in. If I do 10mm, the gear will spin with good contact, but nothing will come through. I'm using repetier so I can also do 10 or 50 seconds of slow feed, sometimes I will get a little bit from this, but it will stop even though the gear is still turning. If I gently push on the filament I might get a little bit more, but not reliably and this is obv not a solution.
I've tried 200-210 C (just using PLA), 3 different spools including the one ya'll sent me, adjusting the tension screw all over the place, cleaning all the parts, replaced the nozzle (.35mm), and everything else I can think of. It seems to me like the filament isn't getting hot enough, or staying hot. But the nozzle and hot end are hot to the touch. It seems like if I leave the filament in the hot end for a while, I can feed a bit through, but then the next section of filament has to heat up for a while (minutes) before it will feed.
I had the printer working wonderfully for about a week. This all started when I tried to change rolls of filament (still PLA, just different color), and it jammed up. I cleaned the jam from the hot end, and it hasn't worked since. Maybe I damaged the hot end??

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Jules
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Re: Can't extrude properly

Post by Jules » Sun Aug 14, 2016 6:33 pm

Still sounds like there might be a partial clog in the nozzle. (not the whole hot end)
Go back to your original spool of MakerGear PLA and use a 215 degree melting temperature and see if you can get it extruding again. If that isn't successful, you might need to either disassemble the hot end for cleaning with a torch, or it might need to be replaced. Impossible to tell without seeing it. (Might need to open a Support ticket with MakerGear.)

(Before you do though - see the next post.)
Last edited by Jules on Sun Aug 14, 2016 7:43 pm, edited 2 times in total.

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Jules
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Re: Can't extrude properly

Post by Jules » Sun Aug 14, 2016 7:11 pm

Tell you what Ripley, you've said a couple of times that you've changed the tension on the Filament Drive Screw....did you retract the filament after feeding it in and look at the end to make sure that the filament wasn't stripped? (following that guide that I linked to?)

Do a feed and retraction, pull the end out, and take a close up picture of the end that you take out of the machine so that I can see the tooth marks and check it out. (It helps to hold it up in front of a light source, like a computer screen, to show the bites.)

Switching to a different filament generally does not cause clogs or damage to the hotend or nozzle, and you have been using nice low temps for PLA. I still think it might be that your Filament Drive Screw tension is too loose. That nut on the back of the bolt might have worked itself loose.

I want to see a picture of the tooth marks. You probably have one of the new gears with the smaller teeth - it might need to be tightened up more.

RipleyLlessur
Posts: 11
Joined: Sun Jul 17, 2016 12:31 am

Re: Can't extrude properly

Post by RipleyLlessur » Tue Aug 16, 2016 5:24 am

Thanks Jules. Attached are a photo of the filament and another of the printer head. This filament was at the tightest screw setting i could have it at and still load the filament. I have been examining the tooth marks since the beginning, but they never seem to change very much, regardless of the setting. I have tried many settings of tension, and I pull the filament out, clip it, and reload it each time. The gear on the teeth are very small and I don't think they are capable of biting much deeper.
The head doesn't seem to function the way I would expect. Only the very front of the gear makes contact with the teeth, and same with the smooth wheel. I tried to photograph this. It looks like the filament is more far forward then the gear sits. Like, I would expect the filament to run down the middle of the gear, but instead its all the way at the edge, do you understand? I'm suspicious that the filament may be too far forward and getting pinched between the housing and the gear/wheel.
I've cleaned the hot end a few times, and replaced the nozzle, so I don't think there is a jamming issue, though when the printer missfeeds it does jam sometimes.
I've had this printer for a month now and have gotten like 6 successful prints. I'm very appreciative of your assistance Jules but I'm getting pretty frustrated since I haven't been able to print in over a week and was expecting to be producing things for clients by now. I expected a sharp learning curve, and I understand it's new tech, but this is more than I bargained for. I'll be out of town for a few days so I won't be able to try new fixes until the weekend...
Attachments
Head1.jpg
Filament1.jpg

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