I built a custom delta using 3, 1000 mm long C-Beam® Linear Rails and 3 C-Beam Gantry Sets. I had the bottom and top plates water jetted ( for accuracy ) out of 1/2 inch aluminum, from a design that I did in Fusion 360.

probably as big as you'd want it...

Custom painting machine in designed and wrote the software for. Paintings are with acrylic color on canvas

This 1500mm tall Delta is a work in progress. The triangle corners are water jetted from 1" 6061 Aluminum, and are welded to 1" square tubing. The 1500mm OpenBuilds 20x20 V-Slot extrusions are held into the corner brackets by two stainless steel set screws per bracket. This printer will need to be reinforced with wall brackets due to the combination of height/materials.