And conversely, same filament, same settings! Since I have been printing with a lot of other filaments since the last time I printed the big crystal in late Oct. I have been using colored filaments and they have all been working great at 50mm/s. The filament I am using for this project, 3D Solutech Natural Clear, does NOT like to extrude at that rate. It starts to push back and then bends out of the feed path at the drive gear.
I am running a test print right now at 35mm/s (I had to go back to an old gcode file and decode the settings I used last time) and it is working great. I will try out the big print in the morning (too loud to print stuff overnight at my place).
This is a great time to point out that you should ALWAYS document not just your steps, but your settings. While I am good about this at work, I am not very good at this for my projects, it is one of the reasons I started documenting my projects here.
One of the other things I double checked form the old gcode file is the infill. The final print form Oct. was at 30% infill, I am going to try this one at 15%, again to save material, sped up the print time and to also let more light through.