I was having issues with my X carriage and as soon as I saw this, printed and it was a night and day difference, AWESOME design. One of the issues I had with my stock x carriage were the bolts would eventually loosen and I would have play in the X carriage. I took the original design and sliced off what was not needed to keep the bolts aligned with the front.
This also gave the perfect place to attach the belts if you are using the gantry plate upgrades from here https://www.thingiverse.com/thing:2580773 or any other gantry plates that separate the bearings.
X5S-back-carriage-support.stl | 39.9KB |