Problems with Overhang & Loosening layers

Hi guys,

I'm out of idea's to fix this problem i have...

I'm currently working on a Prusa i3, with a 0.4mm Prusa Nozzle,
Most of the problems i had after building were fixed by googling a lot... but this two problems keep on giving me headache's

Currently printing 0.25mm layers with FormFutura White ABS at 240°C... i added my current config.ini as attachment (spekconfig.ini)
I have a 40mm fan running between 50% & 70%

On the pics i added you can see two problems,
1:
I have some layers that don't stick well toghetter, i followed some advices i found on this forum, and other advices on google,
I already played with temperature but i don't see any difference, (between 210°C & 250°C), turning fan off doesn't make a difference...

2:
Overhang-blobs & ooze,
As you can see on some of the pictures, while printing this fanmount, the screwholes get a little messed up on the outside
When i need to print small parts with overhang, i get some blobs on the outer corners, 70% of the time, the blobs build up, and they hit the head and break loose the object.
Have this problem with or without fan running on it, and on different temperatures...

In both cases i played a bit with the extruder multiplier, but it doesnt make a difference

Can you guys help me out a bit?


Thanks a lot!


Spek

Edit: Please keep your language clean.

Edited 2 time(s). Last edit at 10/31/2013 06:54PM by NewPerfection.

Don't take the temperature to 250°C. Even if it's a Prusa All Metal. You should stick with a single temperature for now, and figure out what the real problem is.

1. It could be the filament chemistry itself. Sometimes you get a bad batch. I average about one bad spool a year. Right now, it's a spool of black ABS that I bought on eBay. The other colors were all fine, but the black just would not stick.

2. It could be the speed of your print. There is not shame in printing slow. It's a known fact that slow prints turn out better than fast prints. I cannot think of a single instance where the opposite is true.

3. Start with a less ambitious layer height between 0.3mm and 0.4mm.

Quote
jcabrer
Don't take the temperature to 250°C. Even if it's a Prusa All Metal. You should stick with a single temperature for now, and figure out what the real problem is.

1. It could be the filament chemistry itself. Sometimes you get a bad batch. I average about one bad spool a year. Right now, it's a spool of black ABS that I bought on eBay. The other colors were all fine, but the black just would not stick.

2. It could be the speed of your print. There is not shame in printing slow. It's a known fact that slow prints turn out better than fast prints. I cannot think of a single instance where the opposite is true.

3. Start with a less ambitious layer height between 0.3mm and 0.4mm.

Thanks jcabrer!

I got them a little better, i found out that my Prusa nozzle wasn't 0.4mm at all... it's rather something like 0.46mm... i was quite disappointed by that... but after changing that in slic3r, and recalibrating again, my prints became much better...
But not perfect at all... the first corner of the overhang goes perfect, but the second corner, is more round, what gives problems on the 20 to 30th layer...
I'm going to print slower and cooler...

I'll keep you updated, and thanks a lot for your reply

Kind regards,


Laurens