I've lost my quality!!

OK - I've just had days of really, really nice print quality. Yesterday, however, it seems to all have gone to shit. I've been having (until now) success with the Standard Tantillus Config settings for Slic3r.
{Oh, and I figured out what was giving me the errors when using pronterface and trying to load the configs -> pronterface was loading Slic3r 7.1, rather than 7.2b. So that's solved.}

So my extruder has started to get really noisy and it seems to be wigging out (short vids here and here).

I noticed a bit of slop in my zip tied extruder repair, so I tightened them and added a big daddy for good measure. I turned up the pot as well, but am hesitant to turn it much further and have another one blow. It's currently turned about 100 degrees.Unfortunately, I'm unable to print a new extruder with it running like this.

So I'm not sure what's up. I've had great and shite results with the same material, and config settings.

I've attached a couple pics to show the difference from a good print to the bad one I just did (I've cancelled a number of crap prints already). The green material print was done on the standard draft config (first time using it), but don't think it's supposed to look like that.

I'm thinking that the unrecognizable honeycomb pattern is likely due to the extruder either not retracting properly or extruding enough. This is all coupled with a some slight misbehaviour of the z-axis.

Any thoughts are most welcome. Thanks!

I would say the hotend is clogged a little which increases the pressure and results in the extruder skipping steps. To clean it you can use very thin wire or a 0.45mm (or 0.3) drill bit to clean out the hotend nozzle hole while pushing some filament in the hotend (while hot, be careful). To do this you will have to remove the bowden tube from the carriage temporarily. I have heard you can also heat up the hotend and put a piece of filament in it (with the bowden tube removed). Then turn off the heater and wait for it to cool to about 70c at which point you pull out the filament and the dirt comes out with it.

Edited 1 time(s). Last edit at 09/09/2012 03:17AM by Sublime.

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Ok - I'll give that a go in the morning. Thanks.

Thanks for posting this. It definitely helps with recognizing future potential symptoms. I was wondering about what to do if/when the hot end clogs. I'm using cheap filament too and have already seen some evidence of dirt.

Edited 1 time(s). Last edit at 09/09/2012 03:14PM by Lisa M.

One thing which I do to help remove surface dust/dirt from the filament is to print off one of these: Universal Filament Dust Remover. Put a little bit of a clean kitchen sponge in there and run your filament through it and it should help to reduce the amount of dirt/dust that gets into your hotend. I found that it helps especially with some of the lower quality filaments.

If the filament is foaming or bubbling coming out of the Hotend, it's absorbed some water, you can stick it in the oven on very low for a couple hours and it might help.
The real I have from them neede the temperature lower than the other PLA I've printed.
The other thing about the repraper filament is the spool of 1.75 I have is actually closer to 1.65, so measure it and make sure you have the measured diameter in the slicer.

Good tip Gerald - I just tried printing it and it came out with the density of a cheesy.

So I've attached a pic of some extruded filament (this happened when I used the LCD to unload filament - it went nuts and started extruding and making a bunch of noise) that shows how filthy this stuff is, or how dirty it is in my hot end (that just doesn't sound right ).

I just wanted to post a pic of what this stuff is looking like. Otherwise, I feel like everything just keeps getting worse here. I can't even get it to preheat the PLA to allow me to unload it and clean the print head. Grrr.

I think it's best I step away from it for a while.

Yeah that is most likely the cause of the jam. You say it will not pre-heat, can you explain how/why?

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I dunno what's up with it. The red light turns on as soon as I click pre-heat (both LCD and pronterface) but there's no change in temp. I had to walk away and get my ass outside. I'll look at it tomorrow and see if I can figure out what's up.

@Polygonhell - I'm printing 3mm and there's no bubbling or foaming that I've noticed. I'll keep an eye out for that though.

Cheers.

ernchesto Wrote:
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> So I've attached a pic of some extruded filament
> (this happened when I used the LCD to unload
> filament - it went nuts and started extruding and
> making a bunch of noise) that shows how filthy
> this stuff is, or how dirty it is in my hot end
> (that just doesn't sound right ).

That filament looks very much like what I experienced when I had problems with my extruder. At first I thought it was dirt or contamination in the filament, but it turned out that the extruder wasn't pushing out the filament consistently. I got cheesy prints, what looked like bubbles, and dirty looking filament. The 'dirt' was actually burnt filament. Once I squared away the extruder problems, the same filament from the same spool prints like a charm.

In my case the extruder problem was the small gear slipping sometimes, but not always, on the shaft. I ended up filing a flat on the stepper motor shaft and using red Loctite (the weakest grade) on the set screw.

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Lem Fugitt
3D Printing Dreams
Robots Dreams
"The map is not the territory."

Robots-Dreams Wrote:
-------------------------------------------------------
>
> That filament looks very much like what I
> experienced when I had problems with my extruder.
> At first I thought it was dirt or contamination in
> the filament, but it turned out that the extruder
> wasn't pushing out the filament consistently. I
> got cheesy prints, what looked like bubbles, and
> dirty looking filament. The 'dirt' was actually
> burnt filament. Once I squared away the extruder
> problems, the same filament from the same spool
> prints like a charm.
>
> In my case the extruder problem was the small gear
> slipping sometimes, but not always, on the shaft.
> I ended up filing a flat on the stepper motor
> shaft and using red Loctite (the weakest grade) on
> the set screw.

That seems quite plausible to me, as the troubles started when my extruder started making all the knocking sounds and it appears that the there is something up with the gear meshing/slipping. When the knocking is happening, so is the messed up print quality. You may have just saved me a bunch of time. Thanks.

Well, I'm still having the issue of no pre-heat. I've inspected the board (to the best of my knowledge) and inspected and re-attached both the heater wires and the thermometer wires to the board.

Is there anything else that I can try/check before I have to remove all the shrink-wrap, connector sleeves, etc. This is something that I'm really not that keen on doing, as it seems like a bit of witchcraft for one of these connections to have just gone and disconnected itself.

Thanks.

Can you test the power supply? Yonderboy had a problem where his heater resistor did not fit as tightly as it should and he did not have any tin foil wrapped around it to make it fit better and it resulted in the resistor reaching incredibly high temperatures to heat up the brass block which then resulted in the resistor burning out. To test the resistor you can remove the wires from the screw terminals on the Ramps board and then test the resistance. It should read 5.6ohms. If it read infinite resistance then it is burnt out.

Edited 1 time(s). Last edit at 09/10/2012 03:32PM by Sublime.

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Sublime Wrote:
-------------------------------------------------------
> Can you test the power supply? Yonderboy had a
> problem where his heater resistor did not fit as
> tightly as it should and he did not have any tin
> foil wrapped around it to make it fit better and
> it resulted in the resistor reaching incredibly
> high temperatures to heat up the brass block which
> then resulted in the resistor burning out. To test
> the resistor you can remove the wires from the
> screw terminals on the Ramps board and then test
> the resistance. It should read 5.6ohms. If it read
> infinite resistance then it is burnt out.

I've attached an image of the resistance the way I set it up. I'm a twit with electricity, so wanted to include the setup to ensure we're talking about the same thing. I wasn't able to get a reading on anything under the 2000k setting. It ranged from ~1800 to the ~800 shown in the image, although for this I was holding both ends in one hand.

So I'm thinking that this is the culprit? Shall I go ahead and use my second resistor? And the tin foil that you mention, should I wrap to make it so that it's, say, a good push to get into the hole?

Thanks again for your help.

Yeah I would say you ended up measuring the resistance of your body and got 779,000 ohms of resistance. This makes me think the resistor is dead. On Yonderboys it was a result of the resistor being shaped like a peanut so it felt as if it was a tight fit but the center was not making any contact at all. So yes use the other resistor and wrap the center of it with tin foil until it is a nice snug fit.

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OK, thanks. I'll do that this evening.

Alrighty - swapped the resistor out (it was cooked), and now I'm able to pre-heat

Now to see if the extruder is still being a bastage....

Well, yes it is. It was skipping and grinding while extruding.

So I unloaded the filament and needed to assist it by pulling. While pulling, the hobbed bolt rose up ~3/16" (see attached).

This makes me wonder if my troubles are related to the loosening nut on the end of the hobbed bolt - anyone experience this. The main reason I'm asking is that I'm being lazy and I'm really not wanting to rebuild my extruder, as it's held together (and stabilized to the plexi) with a bunch of zip ties. I just want to get it working enough to print another extruder housing and then reassemble it the one time.

And here's a shot of the burned resistor FYI.

Hopefully my final update:

So I took my extruder apart and found that the loosened hobbed bolt nut was the culprit. The attached image shows how it had dropped so low that it was, in fact, grinding its way into the servo - causing all the excess friction and wiggy extruder behaviour. What do people think about addressing this issue, as I'd put my money on it happening again. Loctite? - the red stuff that Robots-Dreams suggested?

I feel like I just rebuilt the printer (now I'm getting a better sense of what all you reprappers have been doing. This time I took a bunch of time to level the bed and the end stop. I'm printing a test piece that looks frigging AWESOME!!! The printer sounds happy too.

One thing that I'm noticing is that the printing doesn't stink any more (no more overheating resistor). I was getting rather bummed (and headaches) due to the stench of the burning PLA. So if your printer starts to stink while printing - you may want to check your resistor.

Good to know about the resistor and extruder. Thanks for posting your process.

The lose nut did happen to one other person and they just re-tightened it and has not had the issue since. I guess I should add that it needs to be really tight to the instructions. Robots-dreams had his small gear come lose and used the loctite on the set screws. But either way loctite may not be a bad solution.

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I had it loosen too, and found that over tightening it made for too much friction against the bearings in the extruder. So I tightened it against the nut on top of the extruder gear, locking them together really hard, and that seems to have done the trick.

Now I just need to figure out why my machine's extrusion rate slows down for 10-20 second periods during a print. Not the extruder itself, just the rate of plastic coming out of the nozzle seems slower, generating weak patches in the print.

neptix Wrote:
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> Now I just need to figure out why my machine's
> extrusion rate slows down for 10-20 second periods
> during a print. Not the extruder itself, just the
> rate of plastic coming out of the nozzle seems
> slower, generating weak patches in the print.


It could be your idler is not tight enough and the filament is slipping. With the filament loaded tighten the nuts so the springs are compressed to the point where all the coils are touching each other but not so much that they start to deform or overlap themselves.

It could be you are using the smaller diameter Bowden tube with filament the goes over 3mm in a few spots and is causing the friction to increase which in turn makes it not extrude.

It could be the same issue that Robots-Dreams had where the small gear on the motor of the extruder slips every so often.

It could be the filament is really inconsistent and the diameter is so much less in one spot it simply has less plastic.

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