Vertically inflated edges and corners

[wonderemporium]

Has anyone seen a printing problem like this? I'm using a brim and the bottom layers are holding just fine but as the build gets taller, the edges get higher faster than the inside parts of the print. Because of this the nozzle strikes parts as it goes over and it's a general mess. I've tried changing many parameters but the overall effect still seems to be like there is too much material on the edges and corners. Notice that the corners are also kind of "pulled" in making them round. This is the lower part of the calibration cube so the corners are supposed to be sharp.

[Polygonhell]

It's usually caused by too much plastic being extruded, or the temperature being too high, or printing too fast.
Print a single wall hollow cube, and measure the extrusion width, then compare it to whatever slicing software has set it to, in Slic3r it's the value noted in the comments at the top of the GCode.
For Cura/Skeinforge or KisSlicer it's the value you set the extrusion width to. If it's too wide, you can either reduce the ESteps in the firmware, or Mach3, or change the extrusion multiplier in the slicing software.
Once you've set your esteps to the correct value based on that, I would print a 100% fill cube , stop it after 10 layers or so and look at the fill, if their are small gaps you'll have to increase the value slightly again, if the extruder is running into the fill, reduce it slightly.

The reason that setting the number of mm of filament coming in to the extruder is not sufficient is that the slicing software uses an approximation of the output extrusion cross section, then assumes volume in = volume out, but it's only an approximation.

[wonderemporium]

Thanks for that info. I'm now dialing in the combination of temperature and flow rate and have gotten rid of that effect, although I seem to be at a choice of gaps or too much material. So far the exact right amount is eluding me but I'll keep tweaking, the right numbers have to be in there somewhere.