N) Aligning your RailCore

The first step is to align your belts. Adjust the steppers so there's some tension, it doesn't take much, just enough that the belts are straight.

Loosen the bolts holding each stepper and idler mount, and move them on the frame until the belts form 90 degree angles to each other.

Earlier in the process you should have made sure your belts are equal lengths, if you did, that will make getting proper tension easier.

Each X Carriage has two bolts retaining the Y rail in place. Loosen those bolts in both carriages just a little before proceeding. (They should still keep the rail in position, but should not be tight)

Pull on the Front stepper in the mounts to lightly tension the front belt. You don't need too much tension.

Pull the rear stepper back in the mount until the measurements marked in red on the image are equal. (Measure from the right side of the Y rail marked in red, to the left side of the top right extrusion where marked in red).

1-2-3 blocks can be used in place of measuring.

Once the Y rail is squared you should re-tighten the bolts in the X carriages to retain the Y rail.

Ideal belt tension is between 40 - 50hz as measured on the short spans on the left of the printer between the idler mounts.

Center your X rails by loosening the retaining bolts and installing the alignment jigs on opposite sides of the rail.

Tighten the rail back to the extrusion and repeat for the next X rail.