anet a8/prusa Z wobble fix

thingiverse

This fix has completely eradicated any and all Z wobble on my machine, but getting it to work correctly will require a bit of patience and effort beyond just printing everything and installing it. First, I had to install a spring from the harbor freight spring kit that's pictured, but it needed to be trimmed down in small sections to get the correct lift off the sliders. Too little would cause the carriage to bounce, while too much would create excessive friction and prevent the sliders from functioning properly, retaining some Z wobble in the process. The springs are only there to take the weight off the sliders, which will result in noticeable movement on the part that bolts to the lead screw after this has been done. The heavy side with the motor now moves more than it ever did without the springs and before they were installed. This can completely eliminate Z wobble if done correctly or at least it did for me. Once I had this done, I noticed some ghosting, which was caused by the support that came from the lead screws before being removed after completing the previous steps and emphasizing the play already present in my Z-axis bearings. So, I printed the bearings listed in the included files for the Z axis. This also requires some trial and error because it needs to slide freely without any play. To prevent binding, I sized my bearings so there was only zero tolerance on the part of the bearing that's first printed on the print bed. The first couple of layers are always a little expanded or tighter than the rest of the print, so make sure these ends go on the outside or on the top and bottom of the Z-axis carriages. For now, I've only installed one of these bearings per side. I put them on the bottom on both sides and left the factory roller bearings sticking up a little less than an inch on each side to allow room for the printed bearings. If you can't afford to lose an inch of Z height, install two printed bearings per side with zero tolerance ends facing out.