K8200 simple Z axis improvement - gain advantage of trapezoidal rod by deleting free play of the nut on the threaded rod

thingiverse

Hello to everyone! This is my very first upload here. I made it because I was having issues with print quality due to a weak Z axis. Like many other K8200 owners, I've found that the Z axis isn't moving smoothly and precisely because of some free play. Some people have fixed this by adding an extra leading rod or replacing the threaded rod with a trapezoidal one. But I discovered an even cheaper and faster solution. It turned out that there was some free play between the nut and thread on the rod. Gravity would counteract it, but not enough when the Z arm was in motion. So, I added another M8 nut above the stock holder, with a spring sandwiched in between them. I tightened the extra nut to eliminate any more play and then reassembled the thing. My holder simply keeps the nut from spinning - it doesn't apply any pressure from the top or bottom. You can see a picture of the parts before (in blue) and after (in yellow). Gregor's advice inspired this fix! I'd like to add that while building manuals don't mention disassembling linear bearings, I highly recommend greasing them inside with machine oil. You should also grease the threaded rod, as shown here. This will guarantee smooth operation for a long time. Have fun printing! I'm Grzegorz "e_gregor" and thanks for checking this out! Instructions I made these parts on my regular K8200 printer. Here's what you'll need: 1) A spring, about 20-30mm long with an internal diameter of 8mm 2) An M8 nut 3) Some filament (just in case!)