Anet A6 X-Timing Belt Tensioner

Belt tensioners for the Anet A6 Y-axis are quite abundant.
Here is a solution for the X-axis.

Cut / engrave it with a lasercutter, 4mm acrylic is perfect.

Or print it with your 3D printer. Tinkercad can extrude it from the svg-file. Add the engraved notch for the metal X-sledge belt attachment.

Tap the bigger part with M3, drill the smaller part 3.0mm.