I'm building a machine that needs more axis than one SmoothieBoard can supply.
Think XYZ motion with an additional rotary axis tilting the tool (not a spindle, it's about precise tilting between 0 and 90 degrees) and automatic tool measurement and change facilities.
In operation, the machine will largely execute 'standard' XYZ movements. In between, it will need to go to a special position, open up the tool gripper, move the tool magazine, close the gripper, tilt the tool, then run standard XYZ stuff again.
Overall, I am currently planning with 3 steppers for XYZ, one for tilting, one for the gripper, and two involved in tool magazine handling - 7 steppers in total, all with end stops. Only 3 of those need to be quick, jerk controlled and move in sync - the others can be slower, they don't need to move in parallel, and they won't move while XYZ movements happen.
I'm currently evaluating which controller would be best and am having a hard time finding something with enough electrical extensibility and enough software flexibility to allow for simple movement control as well as special stuff happening in between.
I would value your opinions on the following idea: Use several SmoothieBoards. Have one control XYZ, use others for the other stepper axis. Control them from host software running on a PC via Ethernet, sending gCodes to each one in turn as processing requires.
Would that work? Does it make sense?