1 Topic by dteck

  • dteck
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  • Registered: 2013-04-26
  • Posts: 17

Topic: Yet another SD2 extruder/chewing problem.

here we go.

extruder gets a piece of red filament stuck in it.
Open tension arm on jigsaw to remove
now feeding filament is a nightmare – works randomly, starts chewing up filament whenever you aren't looking.
Spend hours playing with tension screw trying to find out if too tight or to lose.
Notice that on occasion it is impossible to feed filament through hotend – would have better luck pushing through brick wall than through peek/barrel.
Take jigsaw apart because I thought I might have a clog.
Disassemble hotend
Give brass a good scrubbing with acetone and some lemon juice. - clean as can be inside
Replace jigsaw with MK4 for easier troubleshooting in future.
Reassemble and spend a day filing the back of the mk4 base down so that the peek sits more directly under the extruder gear. - was having problems with filament bending and breaking rather than feeding down.
Things seem peachy for a bit. White filament from SD feeds and flows well.
Switch over to Black filament from ebay that had been working fine before with jigsaw.
SD randomly stops extruding and just chews filament.
Slow my speeds down thinking that maybe because they were cranked up the filament didn't have time to melt completely. - seems to work, black comes out clean, not having any chewing problems.
Decided to do 4 hour print
3 hours in SD stops extruding, filament bends and starts gathering on top of peek.
Pull open tension arm and cut filament then try to manually feed some through peek/barrel – back to trying to push though brick wall.
Screw it, go to bed

Also important to note.
Constant 200c hotend temps with little to no swing.
The bed is level and there is no crashing
spools are sitting above the printer being fed down through the open top of the machine, and not binding on anything.
And after looking at some other threads I guess I should mention the fan on the extruder motor is working fine. I don't think it was the motor heat softening the filament. Especially because it feels like there is a brick stuck in the peek/barrel.
Sometimes when the problem happens if I stop the print and tell it to manually extrude it seems to work fine but then jams up again when printing.
I don't know if its from a gap between the barrel and the peek as was mentioned in another thread but ill try tightening it in the morning when I get home.
Also it isn't just the black filament, the SD white would also jam up randomly but very rare, and using the red is just asking for problems.



In the mean time any thoughts on what else it might be. Also has anyone swapped hotends for something else like the j heads's from ebay? Mostly I'm just wondering about how the cartridge heater and the thermistor match up to what SD ships with.

2 Reply by FatalDischarge

  • FatalDischarge
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  • From: Arvada, CO
  • Registered: 2012-12-30
  • Posts: 129

Re: Yet another SD2 extruder/chewing problem.

I've had my j-head for almost a week and I have no complaints. I had issues with the setup, erratic thermister readings, but all has been fine since. I replaced all of the connectors while I was at it, which is nice. My biggest issue is the g-code fan. The current one hangs too low so I have to figure something else out. I got the j-head from here, http://www.tridprinting.com/Hot-Ends/. Seems legit.
As far as your issue, I didn't do as thorough a cleaning as you but I tried cleaning my stock hotend but it never worked right. Just get a new one. You won't regret it.

3 Reply by dteck

  • dteck
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  • Registered: 2013-04-26
  • Posts: 17

Re: Yet another SD2 extruder/chewing problem.

Hi everyone I wanted to come back and update this in case others are having the problem or have it in the future. Today i took apart the hotend again and found that it wasn't clogged in the nozzle or barrel. I seemed to have had some melted plastic that got stuck all the way up in my PTFE liner. now granted that could have happened when i heated the barrel to remove it from the peek but after reassembly and a hell of a good tightening. (perhaps too good, I flattened some of the threads on the barrel). I was able to get a good solid 2 hour print out of it with no problems. so it may have been that after the first clog I hadn't tightened things up enough. If it starts having problems again tomorrow when i do a longer print I'll update this thread.

FatalDischarge - It looks like the one you bought was a resistor heater style, the ones on ebay are all cartridge heaters. Ive seen a few posts on here about them but the responses go both ways on whether or not they are ok to use. I guess i just need to sit down and look at how the Sanguinololu powers the heaters and see if it can handle it.