Finlly I figured out how to print from ABS filament with my sunhockey prusa i3
I'm so happy, ABS seems to be a lot better now compared to my PLA expreiences, my trick is simple, I just read it somewhere:
I took some acetone and soaked some ABS in it (actually filled a 100 ml bottle with about 50 ml acetone and ABS) took an old primary school paint brush and gently painted a layer of "liquid ABS" on my 90 degrees celsius heated bed, soon the acetone vaporised, and a tiny extra layer of ABS got stocked to my bed so badly
I can only remove it with a razor blade, on this I print 5 layers of rafting, after that the print can start and now it seems even bigger (for me at least) 4-6 hour prints came out fine.
I'm so happy just started to print plenty of things again :-)