Using two or three independant z axis?

On my machine i set them up for dual z axis.. This way i could have a mill on one and plasma cutter on the other or mill in one and 3d printer on the other.. I see in cambam i can easily change the clearance plane axis from z to a,b,or c .Let's say i wanna leave one of them as the z axis and then make the other into the a axis could this be done in marlin by just going into the pins and changing the e1 to a ?or would it be done somewhere else?I'm thinking it would be nice to just be able to change the post processor from z to a when doing milling or 3d printing or be able to do multi tool op with the plasma cutter and plate marker without having to unhook wires or do other changes to the machine?I know it seems like i'm doing to much just wanna be able to ad some of the features i was running on my big cnc plasma tables.Like rotary axis,plate marker,mill and plasma on separate axis?On my next machine i build for me i am gonna have dual gantrys,rotary axis dual z axis on each gantry so all together it will be a 9 axis machine .i might run two ramps1.4 or slave some of the axis together so i can reduce my cut time by 1/2 when plasma cutting 6x12 sheets of steel

I don't understand?

Does your extruder move up/down over a fixed bed?

How do you have your 4 devices mounted on your X / Y axis?

They must take up a lot of the axis travel?

Why Not ONE Z-axis mount with the 4 tools on it
or
like Hyrel does it pick up the tool you want
[www.hyrel3d.com]

But
a plasma table is vastly different than a 3D print table, or a mill table
How do you handle that?

Mill needs a lot of push where Plasma or 3D extruder doesn't need much power at all.


Are you going to mount your Star trek Phasor to it also?

My machine is built similar to a plasma table with all aluminum extrusion ..the y axis moves the gantry the x axis moves the z axis carriage across the gantry then i have two axis mounted to the z axis carriage ..i have 6.5 inches of z axis travel ..My x axis hax an extra 4 inches of travel more then i need so the cross over lost to the offset of the tools doesn't take away from my work area.My machine uses triple extrusions for the gantry so it is very rigid and lightweight .This allows me to maintain high speeds for plasma and 3d printing and yet have enough rigidity for milling ..I need separate axis for the different attachments so they don't interfere with eachother....Also independent axis allow me to just write the different tool ops into the g code and not have to stop between using different tools ..

His setup is basically a 3d printer that is made out of better materials and has interchangable heads mine is basically a cnc milling-plasma table that has been adapted to do everything....I was thinking of adding a bring me a beer attachment ?