Enhanced Anet A8 X-Axis Belt Tensioner

I made this design based on the Improved Anet A8 RepRap X-Axis Belt Tensioner by WedgeSD, which won't work with the stock Anet belt and won't fit into an IKEA Lack Table enclosure.
You only need :
- 1 M3x30 screw
- 2 M3 nuts
- 5 M5 washers instead of a pulley
- no belt upgrade needed
- a metal cylinder of 5mm diameter and 8mm height (see EDIT)

The parts are designed to fit exactly in place, but I needed to do some sanding and lubrication (PTFE) to get it to work.
With this upgrade, th