Vzbot belt tensioner for z sync, I'm using the original motherboard on my tronxy x5sa cheap build, so I have no z axis sync (one driver for 2 motors), to compensate I had a kit from aliexpress but the belt is too long, so I needed a belt tensioner made with 2 bearings and a 8 mm rod.

Now there's a new problem, the belt pulls the screw to one side so I had to keep it straight with a reinforcement on top and let the Holdam coupler do their job, in the end I'm quite happy with this setup, z wobble it's gone, and my bed is always level.