My thoughts too. I really can't explain it either. I though at first it might be somehow down to the chamfer at the bottom of the part, but all vertical features seem to inherit it. At least I managed to find a solution.by berk - Mendel90
I looked at the gcode I was using on my other printer and found the extruder temp was 253C. After changing the mendel 90 gcode to match this, the blobbiness has gone.by berk - Mendel90
Hi Chris, Definitely consistent..on every part. Nozzle diameter is 0.5mm and set to 0,4mm in skeinforge. Will check extruded diameter tonight. Tonyby berk - Mendel90
]I seeing blobs on the internal and external boundaries of my ABS prints, but only for the first 10 or so layers and I'm at a loss to explain it. I've calibrated the extruder with the 100mm extrude method. Extrusion temp is 240C, bed temp is 95C (actual) in a heated chamber at 45C, printing on PET tape. The model is sliced with Skeinforge and the filament diameter is set correctly. Anyone any suby berk - Mendel90
I have experienced the same, although slightly worse effect and traced it down to the pololu driver getting too hot on one axis, this caused it to lose steps randomly. Improving the heat dissipation fixed this problem for me.by berk - Mendel90
Made one for my ABS prints. Rather poor quality picture here : http://funwithelectrons.blogspot.co.uk/2013/06/mendel90-heated-chamber.htmlby berk - Mendel90