Place the Y axis assembly into the base of the frame. The tips of the linear rails must rest flat on top of the 492mm profiles, to prevent torsion.

61.5 mm (distance between Y rails and base of frame). This distance should be roughly the same on both sides.

The next steps are the foundation for the rest of your printer. Read carefully and take your time to get them right.

Start by tightening the outer frame. Make sure everything is square and tighten all Corner Connectors first and then all the Joining Plates. Use a squaring tool if you have one.

This side first! Whenever a corner connector joins two profiles, you should always fasten this screw first (the one that is closer to the end of the profile). This really helps to ensure squareness.

Fasten this screw only after the previous one is fastened.

Next, fasten the Corner Connectors on the Y profiles to attach them to the frame. After doing this, you need to ensure that the 2 Y Linear Rails are perfectly parallel. When they are paralell, the Y carriage slides smoothly throughout its entire range of movement.

To do this, start by locking the position of one of the Linear Rails, while leaving the other Rail loose enough that it can move. Slide the Y carriage all the way through, back and forth, to establish the correct position, and then fasten all screws on the second Linear Rail. Start by tightening the screws at the tips and work your way inwards.