Convert a standard 20x20 frame extrusion to a V
Wheel, magnetic arm system at minimum expense. Spheres are 5/8".
Using standard 24mm V wheels on standard 20x20 extrusion can be done by printing one complete Carriage Set for each tower. The carriages are set for 5/8" Spheres and utilize a belt drive. The photos show basic construction. The lower belt attachment is done with one 6mm wide spacer held by a small metal screw (1/2" long) directly into the carriage. The upper mount uses the same screw size to a narrower spacer and goes to the belt with an adjustable tie wrap. The wheels are mounted with asymmetric spacers, the smaller one to the front or inside of the delta and the taller one to the rear. This allows the front carriage piece to ride on the 20x20 for extra stability (room for a piece of slippery tape for smooth travel) and will keep the rear rear carriage from hitting the 20x20 on the back side.
Note: things fit tightly, but the carriage should move pretty freely once everything is assembled. You will need 5mm screws (or 10-24, US) and everything may need a touch of finesse for the best fit. I epoxied the spheres in place and put a dab of CA on the flags. Works perfectly so far....