How to assemble T slot Frame with 4545 aluminum profile?

T-Slotted Framing - McMaster-Carr t slot framing THE ADVANTAGES OF 8020 T-SLOT PROFILES · No welding · No painting · Easy design · Easily modified · Combine several cells into one · Reusable components for triple diamond slot machine wins 30 Profile 4 Slot 30mm W x 30mm H Aluminum Smooth Extruded T-Slotted Bar Extruded T-Slotted Bar Fastenal Sku: 0961287

twin happiness slot T-Slot aluminum extrusion is an ideal material for If I understand correctly, the top frame is not sitting on top of the vertical legs