This design of the Y-axis anchor will not move on the Y-axis carriage and positivly holds the belt.
This design of the Y-axis anchor wraps around both edges of the Y-axis carriage to mechanically locate the anchor and not rely on the low friction of plastic on anodized aluminum. This mod, along with the belt tensioner listed below and the modified Y-axis motor mount has all but eliminated the layer shifting lines i was getting in thin single wall airplane surfaces.
The motor mount is required because the Y-axis end stop has been changed in the anchor and it stops on the motor mount. The motor mount helps stiffen up the Y-axis motor tool
These parts were put on an Original Prusa MK3s purchased October, 2019.
The anchor is generally based on the original Prusa part only because it hold the belt.
original motor mount:
belt tensioner:
https://www.thingiverse.com/thing:2786671
The author hasn't provided the model origin yet.