I used EMC with steppers for my TOS FN20 conversion.
The drives are 9A and 12A 70V from Phytron. No breakoutboard, as the drivers have optoisolated input/outputs.
So far I'm not happy with this solution. I can get it up to F500 before it droops out with following error. This on a 1GHz Pentium. Just dragged in a Shuttle PC with 2GHz today to see if I can tease it higher. You'll get the same problem with step/dir inputs on servo drives I guess. The pro is you can make electronic handwheels by driving the inputs directly.
I may switch to servos later, but have to see if my drives are compatible with EMC. As my drives have their own current/speed/position PID loops that may be a problem since EMC has this built into it.
Leave out the handwheels unless you can make them like the ones originally mounted om my mill. They were without handles, just disks with no protrusions. And with a dog-cluch and a spring so they would only follow the spindle by the drag force. (The mill had a quite fast auto-feed originally) The handwheels can be a real danger on mills of this size!
I will install either electronic handwheels or a joystick. I just have to see first whether I go for servos or keep the steppers.
The limit switches: I must admit I haven't installed them yet. And so far I've hit the clamps/vice a couple of times, but not the limits. That's when you realize it's just a computer and it cannot see your clamp. If you tell it to go straight through it, it will. But it's highly unlikely even a 15mm cutter will come out on the other side.  |