z axis moving during a layer

[bobpellegrino]

I just noticed something on my Da Vinci 1.0a. During a print, the z-axis varies slightly during a single layer. At first I thought my bed was wobbly, but then I saw the z-stepper was turning on purpose.

Right now I am doing a .3mm print, and the z stepper rotates left and right randomly up to a quarter turn during the infill, and slowly but continuously while printing the outer shell.

Is this normal? Maybe I don't really understand how these printers work, but I thought they printed one discrete layer at a time. The prints come out looking fine, so maybe I just never noticed before.

Does the extruder normally dip up and down slightly during the printing of a single layer?

[dkightley]

Its a perfectly normal thing to see. If you have retraction turned on and a Retraction vertical lift value then the z stepper will be moving the bed (or extruder, depending on printer construction) up and down.

Its the extruder being lifted up away from the printed model so the head can travel in the x or y direction without wiping across the extruded plastic.

[bobpellegrino]

Of course, that makes sense.

Thank you.