> > I already have my mill running with a single parallel port but the > > single phase motor is still controlled with a switch because I'm too > > lazy to temporarily wire in a relay. What I do have for my mill is a > > sweet Bergerda 1.8kW AC Servo that works very nicely with step/dir > > signals and has a 2500 line encoder (10,000 pulses per rev) which > > means it needs more than the parallel port can deliver. > > Yes, that encoder will run out of bandwidth trying to get thru that bobs > opto-iso circuitry. So you are out the cost of at least a 5i25 which has > at least 100x more bandwidth at its encoder inputs. I've had to cut and > bypass the opto crap on the bobs several times now. I am a CET, but many > machinists far more capable than I at turning cranks, wouldn't feel > comfortable doing such hacking. >
Actually not a problem. Especially for the spindle. The drive also has a numerator/denominator step multiplier on the input. I tested this by replacing a smaller DC brushed servo that has a 250 line US Digital encoder (x4=1000 per rev) and set the numerator to 10. It was plug and play at that point. Nothing changed with the hal or ini file. Just a smaller AC servo running the X axis. Sweet And I can also program in a numerator/denominator pair on the encoder outputs. So I can make the motor encoder appear like one that has 200 pulses per rev. Aside from the poor manual I'm really liking the Bergerda AC Servos. I may be ordering some more in the near future. > > So that means > > a Smooth Stepper and MACH3 or the MESA 7i92H which is the cheaper > > option and plugs directly into my existing BoB. (part of the > > criteria). > > I'll have to look at the 7i92. Just did, wouldn't consider it as it would > tie up the single net port on most motherboards. I consider a working > network a requirement and all my machines can browse the net. It's pretty inexpensive to order a second Ethernet Board. I have one but the bracket is for full height mounting. I need a short one for this PC. > Take care John. And I'm sure I'll learn something from it. > > I'm definitely learning a lot from trying all these different motor drivers. The one I haven't tried yet is the Gecko DC Servo drive. I have two of those that will probably just be sold. Now that I've played with the physically smaller drives that only need 220VAC input and not a separate power supply I can't see using the Gecko. My DC Brushed motors are 90VDC. The Gecko can't go that high. The next power supply I have is 60V for the knee stepper motor. I'm now thinking about how I'll change to the AC Servo for that. Haven't bothered with the quill. It's locked fully up for now. Thanks for the feedback Gene. John _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
