X 2040 Profile (it has the same length as the X Axis C-Beam)
Angle Corners Set up in previous step 2.
Carefully align the Angle corners so they are perfectly flush with the ends of the profile. Press both the profile and the Angle corner against a flat surface, to prevent the Angle Corner from rotating as you tighten it.
¶ Step 5 - Attach T-Joining Plate to X 2040 Profile
T-Joining Plate, set up on step 3. Mount it right at the middle of the profile (if you have a KillerBee 1515, mount one T-Joining Plate at about 1/3 of the length and the other one at about 2/3).
Carefully align the bottom of the T-Joining Plate so it's perfectly flush with the end of the profile.