Re: CNC Fabric Cutter
You might also consider using Linuxcnc and say a Mesa 7i96 or 7i76e ethernet board. The 7i76e has more I/O (32 inputs, 16 outputs). Both can control 5 stepper motors.
While Linuxcnc does not currently have support to calculate the heading (or direction), there is a pull request of mine that adds this. I as asked to add the heading to the additional features I wanted to add by the Linuxcnc release manager for applications exactly like yours. (ie, to orient your NEMA 23). I believe Mach also has this feature. I've been a bit busy and the Linuxcnc dev team is currently working hard upgrade the current release version so I've not been bothering them with non-essential features right now.
One advantage of Linuxcnc for you is that the Mesa cards use 24 volt field power which will allow you to directly control your air solenoids ( I have controlled 24v air solenoids with the Mesa 7i76e). Linuxcnc also adds you to create custom components that are treated as if they were core components so it is very rich in the flexibility it offers for non-standard applications like yours.
Rod Webster
www.vehiclemods.net.au