Y-bed slider for Geeetech i3 Pro B with 8mm Acrylic frame

In 2015 I purchased a Geeetech i3 Pro B printer kit with 8mm Acrylic frame. Attempts to use this printer has always resulted in unpredictable outcomes, so I set out to improve it (see my other things for successful improvements).

This specific improvement attempt gets rid of the LM8UU linear bearings under the bed, which are part of the Y-axis movement, and replaces them with something that is quieter and which allows me to remove the bed easily (after detaching the Y-axis belt), when needed