Burning Plastic! What profile to you use with ABS?

[SgtToe]

Ok I have two basic questions here:

1. What settings do you use with ABS? I'm using a 3mm role of ABS I got from makerfarm, it is purple but looks pink when printed. The default was extruder at 250c for all layers and the bed at 110c first layer and then 70c after that. After reading and experimenting I am now printing with 230c for the extruder and leaving the bed at 110 the entire print. I had problems printing this tiera for my wife to use in a 5k run until I kept the bed temp high the entire print and added a brim to it. EDIT: Went home at lunch to reslice and print and noticed that I had left the temp at 250 for the extruder, so that may answer my own question #2 below

2. Below are some pics of the printed tiera and there was quite a bit of what looks like burnt plastic, some seems embedded in the print while others appear like drips down the side. Is this normal and you just sand them off or am I still running to hot?

20150428_075315.jpg20150428_075232.jpg

[AbuMaia]

I print 1.75 ABS at 240 for the whole print, and leave the bed at 110 for the whole print. I've not noticed any burned plastic. That might not be a temperature issue, but an extrusion issue. If you're extruding too much plastic, some may glob up on the nozzle and burn there before it gets pulled into the print.

[SgtToe]

Thanks AbuMaia, Glad to here that I am not alone in keeping the temp high for more than just the first layer. I'll be trying another print today at the lower temp. I have calibrated the e steps (or went through the process, and it was spot on so I did not make any changes) But have not gone any further to tune extrusion rates. I need to buy a dial caliper but don't want to spend the money on it. lol

[Draled]

I have some issues burning with yellow glow in the dark abs from Marker Farm. I lowered the temp down to 235 after the first layer. It helped, but but not perfect. I haven't had a chance to do any calibrating, but the default settings seem to be very close. I have noticed when I get the burns its from gobs that cling to the side of the nozzle and then drip at a later point. At some point I'm going to play with the retraction settings and see if that helps. I'm thinking at layer changes some extra ooze out. On a side note, I did change to some blue abs from Amazon and didn't get any burning, but that was just one small print.

Hexagon 40, 1.75, first layer 250, 110 then 235, 90. abs