Improved mounts for Y rod on Anet AM8 conversion, improved belt tensioner. Can be printed from PLA since no plastic part is stressed in Z axis pull. Use drill to grind out the holes for the rod to exactly 8mm. I cut a 3mm thread to the holder for the pulley, you can alternatively drill to 3mm and use a plain rod of 21mm length.
Use M5x50mm or M5x60mm for the tensioner, M4x10 for the mounts to the rails, M2.5x16mm for the endstop micro switch.
Print with 1.6mm bottom, top and wall thickness.