Print Help - Fuzzy Print - Degrades Over Time

Hey Guys,

I am having a printing problem where larger/taller objects start fine then seem to degrade in quality / fuzz out as it goes on. The pictures i've attached should give a clear picture of what I mean by degrade/ fuzz out over time. This print was supposed to take about 8 hours to complete and my estimate is that it started having problems at 2-3 hours (not sure, I was asleep.) I am pretty new to all of this and have no clue what could be wrong. Any advice or suggestions would be greatly appreciated.

Printer: Rostock Delta varient.

Filament: ZenToolworks White 1.75mm ABS at 235 deg C. Hotbed set around 100 deg C. The filament seems to be pretty solid and consistent. All of the small pieces I make come out pretty well.

Hot-End: Gadgets 3D Hotend (buda type)

Slicing program: KIsSlicer. I am using basically the "Beginner" default settings in KisSlicer and I set the speed to 50 between fast and precise with a layer height of .3 mm for a 0.4mm nozzle. Infill is at 25% and doesn't seems to be very clean when i look down in the piece.
Side note I'm pretty sure I have good first layer adhesion as I am not seeing any warping on the bottom.

Thanks,

Daniel

Edited 1 time(s). Last edit at 12/16/2013 01:41PM by ParagonDanaglog.

from my experience, I could be wrong, but it looks like your not extruding enough, Id be hand feeding it to see how hard it is to push filament through ur hotend,

also try lower your layer height, it could also be incorrect steps...

Nechaus,
Thank you for the tips. I adjusted step value for my extruder increased the number of loops in KisSlicer from 3 to 7 . Not sure if it fixed the problem, but ill know tomorrow morning and will post a follow up with my findings.
Thanks again.

Your extruder gradually stops extruding. It's not kiss settings problem. It seems it is overheating and getting loose.
Try to print tall but narrow cube and if it will be fine, try to print in cold environment

looks like you are getting heat creeping up your thermal barrier, causing longer prints to fail, you may need a fan blowing across your barrier

Quote
Dirty Steve
looks like you are getting heat creeping up your thermal barrier, causing longer prints to fail, you may need a fan blowing across your barrier

+1 Here, I had the exact same problem, I could't print longer than an hour or so.
Cool this hotend as much as you can! Printing a shroud will greatly improve from a simple fan blowing at it.

take apart your hot end. clean the bolt that pushed the feedstock, or replace it. I wouold bet that there are plastic chunks in the teeth preventing grip. which brings up another leason. have the power on the extruder reduced. you would rather it skip steps than strip feedstock.

also 1+ on fan for tall builds. you want the hot end not to heat up on the cold region.

on another note, if you find feedstock in the teeth of the bolt, odds are you are running the extruder faster than it is capable. 0.3mm at 50mm/s is quite challanging. I only do above 50mm/s with 0.15mm layers, and that uses 1/4the the feedstock, so 1/4 the flow rate.

Edited 2 time(s). Last edit at 12/17/2013 10:48PM by jamesdanielv.

Thank you all for the above tips.

I took the hot end apart as suggested and discovered that one of the nylon mounts had started melted in various places. I concluded that it was as many of you said, the heat was creeping up to the barrier and wasn't being dissipated properly. This was further confirmed by a finding melted plastic in 1.75mm insert that goes in the barrier.

I am now working on getting a fan hooked up and mounted.

I'll post pictures once I get this fixed so that this feed can have a resolution for future viewers.

Thank you all again for the help!

-Daniel