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« on: October 01, 2008, 03:47:51 PM »
2500ppr will mean Mach needs to put out 10,000 pulses per rev. If you dont have electronic gearing and are using the parallel port you are looking at approx 1350mm/min (asuming 5mm ppitch). There is a device called the Smooth Stepper (as Ray has mentioned) which pulses externally from the computer and it allows pulses up to 4MHz so it is perfect for high count encoders. I have 2000 line encoders and using 1:2 electronic gearing in my drives I was limited to 3500mm/min on my lathe, now with the SmoothStepper I am 13,200mm/min and could actually go more than twice that speed if the motors could but as the lathe is heavy 13m/min is quite fast enough.
Hood