Extruder stops half way through 8 hr print - arghhhh!

As you can tell from the title I'm tearing my hair out! I've tried this print 4 times now!!

Using PLA (at 210/200 degrees now) and trying to print the body of a quadcopter, the print starts off really well - sticks well to vinyl sheet on plate, smooth and strong, all looks good. Then....about 4hours later, the extruder jams and so filament delivery stops. But the printer keeps going "printing" in mid air.

I noticed that by that stage the corners of the print have also started to lift off the bed (tried using cold bed and now using bed heated to 100 - no difference) so not sure if that has anything to do with it? Maybe print "scrapes" the bottom of extruder nozzle?

I've been in touch with Jerry about another problem I have - extruder wires connection failing. Although I have tempered that problem till replacement parts arrive from Robo HQ with some electrical tape! Maybe this issue is related??

Any ideas guys...to preserve my sanity...and hair style!!

 

it could be that the extruder cools down and then it stops extruding but it also could be an inconsistent filament diameter, who do you buy filament from?

btw are you printing the PL2Q?

 

Have tried 3 different filaments now so don't think that's it. 2 from bilby.com.au and another from 3d printer superstore I think.
Was printing the PL2Q then found this one that looked stronger: http://www.thingiverse.com/thing:261145
Managed to get 3 arms printed (although 2 have a bit of warping cos they lifted off the bed part way thru). But the body is impossible for me at this point!


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yeah, its a FPV quadcopter so if you intend on going FPV i recommend it. looks like a kk2.0 might not like that configurations but it might.

good luck

 

This is going to sound stupid but you are 100% sure it is PLA correct? Any reason you opted for vinyl sheet over the usual glass and hairspray with some heat (60 C is usually sufficient). I had an issue where my prints would stop after the first 20 or so layers, the filament always jammed, it was a mixture of cleaning my hobbed bolt and eventually discussing with the filament supplier that we came to the conclusion that it must have been the filament. Is the filament actually jamming? If so are there filament shavings? Or perhaps the heater is cutting out causing the filament to jam in the hot end.

Long prints are always a bit troublesome and nerve racking. What layer height are you printing at?

 

I'm with Michael on this one. Check your hobbed bolt, I bet there's a ton of really fine, ground up filament on it from all the failures you've been having. That stuff acts as a lubricant, which causes slipping. Just open the little spring hatch and clean it off.

Then, go into your firmware and change the acceleration settings. You can do it manually if you have an LCD screen but it will reset every time you print, so you'd have to change it every time. Its easier to just do the firmware once.
Change:
Acceleration: from 3000 to 700
Acceleration Extruder: from 10,000 to 7,000
Acceleration Retract: from 3000 to 1000

Basically what happens, if your retraction setting is 4mm and the hobbed bolt slips during retraction, it'll act like it didn't slip and try to shove 4mm of filament through the hotend wayyyy to fast. It'll stop up but the hobbed bolt still spins, ending up grinding through the filament till there's a big chunk taken out of it. Then it can't extrude anymore. Adjusting your acceleration settings is the easiest way to avoid this.

 

Michel - yes, it is PLA. Have also tried PLA from different supplier with the same problem.
Red Submarine - Yes, I am getting ground up filament in the bobbed bolt each time. Do you pause and clean it out mid-print?? Firmware changes sound interesting and worth a try. I have an LCD screen but see what you are saying about changing it every time! So how do I "go into the firmware"? I have a mac if that makes a difference.

 

Cleaning it mid print won't do anything. It doesn't grind unless it jams. Once you've jammed, the print is ruined.

Try adjusting the settings on the LCD first because it is way easier than all the firmware stuff. Load your SD Card, select "print from SD" and then while the printer is heating up you can go into the "control" menu and drop the values I mentioned earlier. If it works, then you can do the firmware adjustments to make it permanent.

For what it's worth, the names on the LCD you want to change are:
"Acceleration"
"A-extrude"
"A-retract"

 

You're right, but I think the debris is from the markings that the bolt makes on the filament, those kind of "tire tracks" from the filament being pressed on it. By definition, grind = slip as far as extruding goes. If there is grinding the whole time then you would see varying amounts of extrusion throughout the print.

 

I'm having the same issue but with the red ABS from ROBO 3D. It will jam 5 minutes into the print, when I pull thee filament up it is all shave down. PLA is printing fine i have not experienced any issues.

 

Mark may be right here but you haven't given us much information to go on. Use the temps he suggested as a guide, however I print most ABS around 230C. Try printing a few different calibration objects (try this one http://www.thingiverse.com/thing:8757 ) at different temps to see what works best.

If that doesn't work, I'm telling you guys, those acceleration settings are way too high. I've had issues with ABS stripping/jamming because the filament was too soft/flexible, even compared to other ABS filaments. You've got to turn them down or, no matter how hot your extruder is, you'll still have issues when it retracts.

 

Ive been lucky and never had to play with the firmware. Were do you edit that without an LCD?
I guess its as simple as "open your firmware" but having never done that, can you walk us through it?

 

Just open the firmware in the Arduino software and go to configuration.h and scroll down until you find it. It's essentially a text file, and all the settings have comments so you should be right. Have a look and see how you go.

 

Here's a great tutorial page on how to update/change settings in your firmware: https://docs.google.com/document/d/1fryBbKG8rpOCfsWk3UbcJzHEItqHU0iFY7uVRF3sFx0/edit?pli=1

Dropping the acceleration will also make for quieter prints as the printer doesn't rattle itself to death.

 

Once changed, is it save, upload or verify?