After some more printing I am happy with the abs from repraper.com (using some tweaks), but the results with pla is very varied. The black pla goes well at 220 deg, while the blue works best at 177. The green is the most difficult, it burns and warps if too hot but has major splitting problems if too low. I still haven’t found a usable temperature for it yet. To test plastics I have been printing many 4cm hollow Stanford bunnies. I figure it’s a reasonable model with walls and overhangs. I still have many more to print yet I think.
The PLA splitting problems have been problematic, especially for my new printer like when pushed by a screw or a nyloc nut. I have had to repair parts welding them using a soldering iron.
Compared to the PLA the ABS prints with thin streams of extruded plastic. Tracks around tight areas are also sparse. To get round this I have adjusted slicer decreasing the nozzle size and increased the plastic multiplier. For a better solution I need to take a look at the firmware settings and adjust them to reflect my setup.