There are two reasons I installed a second z-axis; one reason was to balance the weight of a direct drive extruder I planned to install. The other reason was to balance the weight of the x-axis in general. I noticed in December that the axis was lower on the right side of the machine by about 4 mm. Considering that my first 3D printer was about 13 inches wide with dual z-axes, I was always leery about having a printer with a wider width and one z-axis. I suppose this upgrade was inevitable.
This installation was easy, thanks to Chris Riley. His video explained every step well. I just had one issue; the screws attaching the holding bar to the motor. I could not get a clear view of the screws in the video and was unsure about the correct size. There were two sets. After looking at the video posted by the manufacturer of my kit, HICTOP, I was able to figure out the proper size. You may ask why I didn’t follow HICTOP’s video instead of Chris’. My answer would be, Chris made a very good video and it was for generic z-axis upgrade kits. That is all.
Chris recommends directing the Z axes all the way to the top and then homing them. My axes did not reach home. The motor began making a noise when it reached the bottom and I turned the machine off. I was concerned that the screws provided for attaching the motor (see photo to right) were not flat enough and that turned out to be the case. I ordered a case of screws from Amazon and waited another week. After receiving the kit, I replaced screws with M3 12s from the kit.
The last instruction Chris gave in his video was to grease the lead screw. I was going to skip this step, but found it was essential. When I moved the axes up and down after replacing the screws, the lead screw squeaked and the x-axis gantry did not go all the way up. I applied some machine oil to a paper towel and wiped around the lead screw from top to bottom. I tested it again and it operated as it should. Mission completed.