moisture in filament or..?

At 1st I was thinking I had moisture in the filament.. the pop is annoying. but.. that loud and often a pop I should be getting marks, or bubbles or something in the print when the steam blows out the nozzle..?


[youtu.be]

Sounds more like your extruder is skipping a tooth or such.
Don't think it is moisture.
One way to quickly check is print with less extrusion.

I'd agree with that - my extruder made that sound at one time. Try doing as Lykle says or some other thoughts:
1. raise the temperature to help soften the filament more (for fault analysis only, accepting that this may result in inferior extrusion)
2. increase the idler pressure
3. clean the teeth on the hobbed bolt / gear
4. use a more powerful stepper / gear the stepper down further

I solved my problem like this by designing and using a belt reduction extruder [www.thingiverse.com] - it works fine now!

thanks guys.. was kinda what I was figuring but being new to the kits/Reprap style printer I wanted to me sure..

took it apart and checks the gear.. looks fine, no teeth damaged or missing.. unit is less than a week old so shouldn't have issues..

I hear getting a stainless gear is better? but if I change gear teeth count or use a diff drive I need to change the firmware correct? (which i haven't been able to do yet)

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Lykle
One way to quickly check is print with less extrusion.

in slicing cut the "filament flow" down to say 97 or 95% that might help correct?
is there better gears? any recommended ones?

What kind of filament is this? I had this when printing Nylon and thought it was moisture too. It can be, but more often it is just to high temperature.

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[www.bonkers.de]
[merlin-hotend.de]
[www.hackerspace-ffm.de]

PLA mostly Hatchbox.. but few others also...

Um, leaving to one side the pop noise you were asking about, what is going on with your print? There are periods which look like normal print movements, and then periods where, for lack of better words, the print head goes bat shit crazy. What's that about?

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JamesK
Um, leaving to one side the pop noise you were asking about, what is going on with your print? There are periods which look like normal print movements, and then periods where, for lack of better words, the print head goes bat shit crazy. What's that about?

That's a time-lapse.

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greenman100

Quote
JamesK
Um, leaving to one side the pop noise you were asking about, what is going on with your print? There are periods which look like normal print movements, and then periods where, for lack of better words, the print head goes bat shit crazy. What's that about?

That's a time-lapse.

LOL, ya.. I was fast forwarding through the silent areas.. LOL

Oh, phew.

now that the video discussion is done.. any ideas on the issue? opened it up and cleaned off the extruder gear.. looked perfect but cleaned anyway.. still doing it.. I'm guessing I can cut the "flow" down in slicing to like 97-95% might help? any other ideas... ?

the belt drive looks good but not much into modding a brand spanking new printer yet.. that and I'm far from up on the firmware/software end of things and I'm sure I'd need to change firmware speed settings?

thinking stainless drive gear might help? hear they are harder? grip better?

Edited 1 time(s). Last edit at 06/06/2016 07:43PM by Thomllama.

Sounds like the motor stalling to me, so not enough torque to advance the filament. That's not a problem you solve by changing the drive gear (um, caveats about different diameter gears, but you don't gain much). The classic problem with pla is heat creeping back up past the heat break and softening the filament in the cold end. If there are any gaps or rough areas in the feed path the soft filament fills/gets caught on them and causes jams or stalls. Heat creep is reduced by good cooling (the cold end fan should run at full power all the time), gaps by careful assembly and sometimes new ptfe liners, and rough spots by polishing the internals. If all else fails a little vegetable oil sometimes helps!

Another possibility is simply exceeding the max rate that your hotend can extrude at. What size nozzle, layer height and extrusion width are you printing at?

If the extruder stepper motor is running cool you can boost the torque by increasing the current from the stepper driver.

I can't see much detail of either the extruder or the hotend, got any photos or links to the vendor?

As a very general note, abs is easier to extrude than pla, but has other problems due to shrinkage and smell. You might want to try some just as a comparison.

Quote
JamesK
Sounds like the motor stalling to me, so not enough torque to advance the filament. That's not a problem you solve by changing the drive gear (um, caveats about different diameter gears, but you don't gain much). The classic problem with pla is heat creeping back up past the heat break and softening the filament in the cold end. If there are any gaps or rough areas in the feed path the soft filament fills/gets caught on them and causes jams or stalls. Heat creep is reduced by good cooling (the cold end fan should run at full power all the time), gaps by careful assembly and sometimes new ptfe liners, and rough spots by polishing the internals. If all else fails a little vegetable oil sometimes helps!

Another possibility is simply exceeding the max rate that your hotend can extrude at. What size nozzle, layer height and extrusion width are you printing at?

If the extruder stepper motor is running cool you can boost the torque by increasing the current from the stepper driver.

I can't see much detail of either the extruder or the hotend, got any photos or links to the vendor?

As a very general note, abs is easier to extrude than pla, but has other problems due to shrinkage and smell. You might want to try some just as a comparison.

well.. LOL.. here's their "manual" for assembly... LOLOL [drive.google.com]


I have tons of PLA from my old printer left which couldn't do ABS do to no heated bed..(little cheap, but still over price M3D POS ) that and ABS smells from what I hear and I have other people in the house that will whine... I will eventually though.

after some thought and investigation My 1st thought is it's feeding faster than it can extrude. Builds up pressure to a point then it pops back, relieves pressure,.. starts to build again. Prints are near perfect, which most other issues there would be gaps or spots or something for a sign of an issue... at least from what I've read anyway...

That's a mk8 style extruder like I used at first. I found it reliable for 1.75mm filament, but it does have a relatively long transition zone compared to something like an e3d. There are a few tricks for making it work as well as possible:

the aluminum block that the throat screws into is the primary route for removing heat, so some thermal grease between the top of the throat and the block helps.

the throat should be as high in the mount as possible. Some mk8 style extruders have a gap between the aluminum block and the extruder gear, and the throat should be as close to the gear as possible (as long as the heater block isn't touching the bottom of the extruder), but it looks like yours has an extra guide part in this area that limits how far up the throat can go. In this case, I guess flush with the top of the aluminum block is the best you can do.

the fan on the extruder keeps the aluminum block that the throat is mounted in cool. It needs to connect directly to 12v and run all the time. Thermal grease between the heatsink and the aluminum block helps draw heat away from the throat.

ya, everything you said is what I got short of using thermal grease... but that's not really gunna stop the popping noise...?

Depends on exactly what's causing it. The mk8 style extruders are weak on cotnrolling the temperature of the cold end, so any improvements there can help. On the other hand, usually when heat creep is a problem with pla the extruder jams solid and the print fails, so that might suggest that it's not heat creep, but you're just extruding faster than the hotend/nozzle can cope with. That would take you back to extruder motor current, hotend temps and the questions about nozzle size, layer height etc.

ya, and the funny thing is.. If I use Printrun, and just tell it to extrude a mess it doesn't do it.