On Sun, 2011-01-23 at 10:29 +0100, Lars Andersson wrote: > I am just curious, in what application is it needed to know motor shaft > position to fractions of a degree even with constant and variable loads when > running at 20000 rpm?
The motor (or rather control system) for axis position (X, Y, Z) control will need to be able to maintain a shaft position within the accuracy requirements for the type of machining done, .001" to .0001" are typical. The accuracy will need to be maintained while cutting which can have a wide range of loads; end-mills, shell mills, taps, etcetera. Tight (low latency) feed back loops are needed. High RPM is not needed or desired. 20,000 RPM is more appropriate for a spindle, where shaft position isn't a concern, except for commutation and maybe tool changing. Or, at least, that's how I see it, but the above and $2 can get you a cup of coffee. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA ------------------------------------------------------------------------------ Special Offer-- Download ArcSight Logger for FREE (a $49 USD value)! Finally, a world-class log management solution at an even better price-free! Download using promo code Free_Logger_4_Dev2Dev. Offer expires February 28th, so secure your free ArcSight Logger TODAY! http://p.sf.net/sfu/arcsight-sfd2d _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
