Thinking out of the box. Possibly off my rocker?

[neilferreri (Neil Ferreri Ω)]

@ehendrix

For some reason I started thinking a fourth axis would be nice for my SPXXL.

Maybe this very recent thread got you thinking?

Rotating axis on Shapeoko CNC XXL Router

The black box runs Grbl on the same chipset as the carbide boards. It’s a 3 axis firmware with four drivers, just like most Grbl boards. The 4th driver is just for dual steppers on X, Y, or Z. When you see Grbl 4th axis setups, they are usually replacing the X or Y axis with a rotary axis. You’d have to lock your x-axis in place, and connect the driver to your rotary axis. Effectively mapping the X to the rotation. I’d like to see Carbide 3d be the first to adopt a beyond Grbl controller (open…

This has been done as long as Grbl has been around. Still 3 axes. You just have to adjust your steps/mm to the rotary axis. You never want to switch steppers while powered.