Combination of rippled front / sides, significant artefacts on underhangs - help?

[printbus]

If the ripple is the same on all four sides (i.e., truly a ripple and not a shifting between layers), the first thing I'd try is printing with the bed heater off. I'm not familiar with the bed design of that printer, but on another printer some people have determined their print surface flexes as the bed heater cycles on and off. If it flexes, your layer height is effectively changing and some layers get squished more than others, leading to a ripple that looks a lot like what you have. As a test, try something your PLA onto 3M blue painter's tape swabbed with isopropyl alcohol.

If the ripples still appear printing on a cold bed, I'd then print a calibration cube or some other object with a known z-height and measure the height of the final print. If the print result is shorter than it should be, it could be that you're not getting the full z-axis movement out of the z-motors due to binding or something.

From there, I'd use a digital calipers to measure the filament diameter at numerous places and see if it is consistent. If the diameter varies, the amount of extrusion volume you get will be varying with it.

And yeah, shelve the overhang issue until you get the ripple issue figured out.