проблема, вызываемая не полными z-шагами, называется z-ribbing
Цитата:
Z ribbing is caused by choosing the wrong layer height for your Z screws. It is more apparent with thinner layers because the percent-error in the layer height is greater, and because the vertical surfaces of prints with thinner layers should otherwise be smoother. The error is much harder to avoid if you use an inch measurement thread pitch (more on this in later) or if you have some microstepping inaccuracy. Because microstepping inaccuracy can be hard to get rid of entirely, you should assume that you have some, and should always choose layer heights that are a multiple of your full-step length. If you are in half-step mode, your half-steps will all be accurate, but the 3/16 step position will not reliably be half a step away from the 11/16 step position, so you should only rely on accurate half-step intervals if you are actually in half-step mode. This error is non-accumulating, which means that after some number of steps, the rounding error will shift to the other direction, creating a layer that is slightly taller (and thus less compressed) than other layers, or that is shorter and over-compressed. Because the volume of the extrusion is constant but the height is not, the width of extrusion will be different and banding will appear on the surface, as illustrated in the photo above and the first two illustrations at the beginning of this article.
To avoid Z ribbing, you should always choose a layer height that is a multiple of your full-step length. To calculate the full-step length for the screws you're using, take the pitch of your screws (I recommend M6, with a pitch of 1mm) and divide by the number of full-steps per rotation on your motors (usually 200). Microsteps are not reliably accurate enough, so ignore them for this calculation (though using microstepping will still make them smoother and quieter). For my recommended M6 screws, this comes out to 5 microns. It's 4 microns for the M5 screws used by the i3, and 6.25 microns for the M8 screws used by most other repraps. A layer height of 200 microns (.2mm), for example, will work with any of these because 200 = 6.25 * 32 = 5 * 40 = 4 * 50.
Полный текст:
https://www.evernote.com/shard/s211/sh/701c36c4-ddd5-4669-a482-953d8924c71d/1ef992988295487c98c268dcdd2d687e