Burning on lighter color filaments

[McClaneZ]

I'm having a problem when printing objects using white or yellow ABS filament where certain edges or spots will have burn marks. At least I think it's burning, as it looks to be brown or near black. I can't get it to reproduce reliably at the same spot on each print, but I'm pretty much guaranteed to get some burn marks somewhere on every print. In the picture, the burn marks are on a pretty steep overhang, but sometimes they show up on completely flat surfaces. I've tried lowering temps down to 210 (from a usual 235), but it still occurs. Any ideas on how to keep it from happening?

IMG_0063_2.jpg

[Bobby Lin]

Hi McClane! You may have to adjust your temperature settings. Normally we start printing with ABS filament at 230C. Try to gradually decrease the temperature by 5 degrees to get the quality of print you want. For more information, you can read this informative article on how to succeed with printing with ABS filament. Hope this helps!

[curious aardvark]

I used to get that on abs with white filament. Don't think I've seen it on white pla.

Not sure it's filament out of the nozzle, but crap coming off the nozzle itself. On some of the steeper parts of the print I think the nozzle catches bits of filament and they burn.

[richardphat]

What character from comic/anime/etc was that from?

And I would also agree with curious, if a brass nozzle isn't yellowish, you're sure that burnt filament will poop on your prints.

[curious aardvark]

looks like mr bump from the mister men :-)
Or humpty dumpty :-)

[McClaneZ]

Actually, no that's a base for a 'Space Explorer Planter'. https://www.thingiverse.com/thing:926249. I cleaned the nozzle really well a few weeks ago, but now I'm thinking I should just buy a new nozzle anyway.