On Thursday 27 February 2014 22:35:15 Jon Elson did opine: > On 02/27/2014 07:16 AM, Gene Heskett wrote: > > I should also mention that servos do their magic by > > exploiting the error budget, limits set before throwing an > > error in the .INI file. The way we gear steppers, in the > > distance they move per full step, normally 1/200 of a > > revolution, will generally translate to an error less than > > may exist dynamically in the servo system. > > On both of my mills (a Bridgeport manual mill converted to > analog > velocity servos of my own design and a minimill with PWM > servos that I sell through Pico Systems) I can get under 200 > uInch > error even at the maximum velocity. I don't know how that > works out in steps in some particular stepper installation, > but it is a pretty SMALL error. > Correction there Jon, damned small error. ;-) My point was that the steppers can pretty well duplicate that unless we were making another hubble mirror.
And can it do it when the servo motor is exerting half its design torque while counteracting cutting forces? I am sure that represents a pretty heavy cut, on either of your machines, heavy enough to deflect the tool more than that. > Jon Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> NOTICE: Will pay 100 USD for an HP-4815A defective but complete probe assembly. ------------------------------------------------------------------------------ Flow-based real-time traffic analytics software. Cisco certified tool. Monitor traffic, SLAs, QoS, Medianet, WAAS etc. with NetFlow Analyzer Customize your own dashboards, set traffic alerts and generate reports. Network behavioral analysis & security monitoring. All-in-one tool. http://pubads.g.doubleclick.net/gampad/clk?id=126839071&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
