I will keep trying. I have three primary potential causes: 1. the extruder 2. the filament, though I've tried many from different sources and filament sizes and colors. 3. the hotend I have a Bulldog XL extruder and Merlin hotend arriving tomorrow (I hope). So I should be able to eliminate or identify the extruder or hotend as the potential cause. I will change one thing at a time, starting with the extruder, then the hotend. Cheers, Duane.