Tevo Tarantula X Carriage Mod

This is my design. It was inspired on this modular carriage.
https://www.thingiverse.com/thing:1839201
I've placed two wheels on top and one on the bottom.
The bottom wheel is adjusted by a screw that presses it against the rail.
This is not an easy project, not for beginners, and it is not perfect.
If you print this pleas give me some feedback on how to improve it.