piercet's original guide looked the simplest way to get the bed cable sitting in a nice position due to my concerns about the heated bed cable breaking as others have had.
Due to the cable sitting inline with the Y-axis pully, the guide needs securing to keep it off centre. Hence the 3mm hole added for the thumb screw.
I removed the lower cover panel to cut the zip tie & pulled more heated bed cable up to the top. This allows the cable to move in a better direction, hopefully reducing the chance of the cable breaking at some point.
I used an old PC case thumb screw to secure the guide against the Y-axis frame. Make sure you line it up to miss the drive pulley for the Y-axis motor.
Anycubic i3 Mega Ultrabase
1st one was printed at 20% infill & it flexed too much when tightened on the thumb screw.