On Mon, 2008-03-10 at 10:49 -0400, [EMAIL PROTECTED] wrote: > Please, I did not in any way mean to be unfair to EMC. I did not mean it > in that way at all. > > EMC is a fantastic program. > > What I mean is that by doing the electronic gearing there is no way to > avoid a condition where a stepper motor is operating at a step rate where > resonance is present. It will happen and there is not anything EMC can do > to prevent it. Its just a condition of steppers that cannot be avoided. > > It's hard to read E-mail and not have the writing be taken in the wrong > way. Don't take my comments to be bashing EMC in any way. It has been > everything I have been looking for in CNC control. I have no issues with > EMC at all. It's a fantastic package and there has been a ton of work put > into it. > > Jim C
I am brainstorming here. I think you stated the crux of the problem with "there is no way to avoid a condition where a stepper motor is operating at a step rate where resonance is present." The mechanical damping can move where resonance happens. I also noticed from other threads, that the voltage the stepper is driven with can change the resonance frequency. I think the ideal would be to move the resonance above the maximum operating speed, so you never see it in normal operation. Isn't micro stepping the most effective tool against resonance? Or maybe an RC filter on the driver outputs to help shape the voltage. Of course EMC is flexible enough to be able to set up some sort of feedback to mechanically or electrically change the stepping characteristics. Brushless DC motors are just low pole count steppers aren't they? I wonder if a stepper driver could be used to drive a BLDC? Though I suppose a BLDC driver might be better. -- Kirk Wallace (California, USA http://www.wallacecompany.com/machine_shop/ Hardinge HNC lathe, Bridgeport mill conversion, doing XY now, Zubal lathe conversion pending) ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
