Quote Originally Posted by roykirk View Post
I seem to have discovered the fix. I lowered the first layer height back down to 100% and it printed just fine. Clearly I need to stop screwing with that. I think aardvark's advice is probably what I'll follow in the future...just print the first few layers thicker and not mess with the extrusion rate.

As far as build surface, I'm using the thick glass plate that's sold by FF. I love it! I just wish I could get PLA to stick directly to it. That's one of those things that eluded me for so long I finally just gave up trying. I now use 3M blue tape which is excellent. Once the model cools it will, more often then not, pop off the bed on its own. I have to remind myself to change the tape once in a while because it'll last that long. For the problematic prints I have a roll of some generic blue tape from the local hardware store. PLA sticks to the stuff like cement. But the problem is that it sticks so well that the blue tape gets ripped to shreds pulling the print off as well as leaving bits of blue tape embedded in the model that are sometimes impossible to remove.

I don't think it is ever a good idea to go over 100% even if the extruder compensates by pumping out more filament. You want that first layer to smash a little more into whatever adhesive, tape, or slurry you have applied to the build plate.

When set your z axis gap in several spots using a piece of paper that isn't the starting point of the print for the zaxis. It will move down .2mm x (first layer height percent). So .2mm x .9 = .18mm, subsequent layers will be .38, .58, .78, etc. This can all be read when looking at the Z moves in the gcode.