I assembled my first 3D printer about 3 weeks ago, a rep rap style printer. After a few days I was getting really good prints. Most of my prints have been failures for one reason or another, but I have managed to get some really good ones and was having a ton of fun. Then I got away from printing for about a week, and now I have this issue where it seems like the print head moves a fraction of a mm every couple layers, and then moves back, creating this stepped wave-like appearance, which is driving me insane. I’ve tried so many things already, greased the rods, re-leveled everything, re-tightened all the pulley bolts, the pulley cables, and I am still at a loss. Surely somebody could point me in the right direction 
SOC3D
2
Oddly enough, try loosening the belts a bit. Also level your x carriage lead screw brass nuts to the metal motor frame on the left and right and then turn one screw 1/2 turn. Is the shift in x and y or just one axis? Talk Manufacturing | Hubs
Hm. Well it seems I found the culprit, the acrylic pieces that hold the y axis smooth rods to the frame were just a tiny bit loose. So it was causing the print head to shift slowly as it added layers, making the wavy stepped look. Thanks for the help!
