Y-Axis Belt Tensioner for Ender-3

This is a remix of Olev's Y tensioner for Anet A2. Olev's original back and slide parts are slightly smaller for M4 bolt and nut. I replaced those parts.
And I replaced Olev's nut with idig3d's knob.

I have done a few upgrade for my Creality Ende-3.

UPDATE 28-08-2019
I modified the side plates of the tensioner because of these plates has prevented
the movement of the Y carriage.