On 4/23/2011 11:12 AM, dave wrote: >> Okay, I'm getting a bit overwhelmed here too. I'm currently using >> steppers on my saw beveler, but have future thoughts of upgrading to a >> servo based system. So, if what Robert shows as necessary, for one axis >> I'd need a servo, an amp, a driver, a bunch of cards for the pc end of >> the affair, an O scope, tons of other test equipment... >> >> Have I left anything out? ;-) >> >> I'm really beginning to wonder if it's worth the expense. >> >> Mark > Single channel servo (clone as necessary): > > ---------------------< power_supply > | > emc -> motion_card -> servo_amp -> motor ( dc | ac ) > | | > -------------------< encoder > > For dc servos it is nice to have a tach for velocity feedback although > cradek has demonstrated a nice way around that. > > This usually gets you several things; increased speed, freedom from > mid-band resonance, usually lots of I/O for limit switches and probably > more attributes I cannot recall at present (too early in the morning). > > Setting up a servo is not as daunting as one might think. It does help > to put a channel on the bench and learn about it while it is not > connected to an axis ( less stuff to damage if it does something > unexpected). ;-) > > I would never connected a servo to a real machine without having e-stop > limit switches in place and tested. Please don't ask why I think this > is important. > > Halscope is invaluable once you start on the real machine. Thanks > JMK! :-) > > HTH > > Dave
Thanks Dave and everyone who's contributed. It's a consideration for a future update. Right now, the machine is working fine on steppers, but I thought with servos, I'd get a better torque throughout the speed range, and maybe a little more accuracy on the positioning. One thing I haven't taken into account is the dual-stepper setup on the X axis. From what I've read, and talked about on the IRC Channel, it's a lot more tricky to home a dual-servo setup, whereas with the steppers, I have just one home switch on the X axis. More things to think about and consider for the future. But thanks for all the info. Mark ------------------------------------------------------------------------------ Fulfilling the Lean Software Promise Lean software platforms are now widely adopted and the benefits have been demonstrated beyond question. Learn why your peers are replacing JEE containers with lightweight application servers - and what you can gain from the move. http://p.sf.net/sfu/vmware-sfemails _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
