Hello,

I have an idea to upgrade my 3-axis CNC custom build to have an additional independent Z axis with another spindle directly behind (opposite) the existing Z-axis. The purpose of this additional Z axis would be to:

1. extend my working area from 24" to around 40" (because I have a lot of unaccessed space that could be unlocked without modifying the X and Y stages at all)
2. allow for bigger tooling, presumably er20, on the second spindle (my current spindle is er11 so only up to 1/4" shanks)
3. increase production efficiency by (theoretically) 3d reliefing a large wood piece with both Z axes acting simultaneously, or one at a time.

After briefly researching this configuration, I found it difficult to find many builds and experiences with this setup. Mechanically and electrically this can definitely be done but I am mostly concerned about the programmable feasibility of this setup.

For example, I use vectric aspire to set up toolpaths and mach3 to run gcode. Assuming I have two independent Z axes with two independent spindles, how easy/difficult would it be to set up tool paths and set up mach3 to:

1. run either spindle by itself
2. run a job with one spindle running the first half, and the second spindle running the second half
3. run two jobs with both spindles running simultaneously on separate jobs
3. run a large job with both spindles running simultaneously on the same job

Some general guidance and/or specific examples of mach3 solutions to this configuration are very welcome. Thank you so much for your time.