The repetition is 14/cm (calculated as 0.71mm/ridge) My X and Y axises are both belt driven.

If I put my finger on the print head as it moves across the X axis, I can feel it "step" across, even when visually it appears to be moving smoothly and at a decent speed.

This leads me to believe that it is the stepper motion. For example, in order to move 50 mm, maybe it is moving in units of 0.71mm - perhaps Marlin is telling the stepper to move 0.71mm over and over again to achieve the 50mm.

Note that I have my stepper drivers (X in particular) adjusted to that they aren't supplying more current than they need, but yet enough so that there are no missed steps (print accuracy and repeatability are both good). Rods are greased so movement across them isn't impeded.

The more I think about it, the more I think I'm seeing the stepper microsteps. If so, what can I do to smooth things out? Or is this just the nature of the beast?

Thanks.