The only problem, is something logically. The bearings don’t fit correctly, what is a normal thing. If I want that all the system works properly and without gaps, it’s very important that both, superior and inferior bearings are in contact with the aluminum guides. In the next image you can see the wrong case:
The way to adjust it’s theorically easy, but it’s a hard job. I must to close both bearing supports, sanding both superior and inferior beams. Doing this I close front bearings, but not the rear bearing. So I decided to use some metal plates to displace the bearing support. As metal plates I’ve used pieces of a metal saw, or if i want a thinnest plates, I use a Cola can.
This is the final view of the bridge totally finished and adjusted.