Why 4x4

[stoneyreef]

Why are the hybrid plans 4X4 looking at the 8020 extrusions the 8ft length are only $10 more on mcmaster carr thus the X axis could be 6ft long?

What am I missing here? What is the limiting factor?

[joecnc2006]

the lead screws at an affordable cost is 6' long, minus the bearing mounts, motor mounts and the actual gantry, it cuts down on the 6' length quick, also using 1/2" leadscrews anything longer could cause to much whipping, you can go larger, use a different drive system and larger materials, but this will add up quick in cost to the machine, the goal here was to make it an easy build and give people a larger DIY machine on the cheap (so to speak) yet still perform very well.

Joe