2013/8/6 Stephen Dubovsky <[email protected]>
> > > It does fix it. The feedback will cause the control loop to shift the > commanded position away so that you ARE on the upslope of the torque > curve. Its fundamentally how servos work. You need to develop > Q(quadrature) current(flux) to get torque. The D(direct) current doesn't > do any work. Technically, once you have feedback in a stepper system you > can fully servo it and not require any 'holding current' if the application > doesn't currently demand it. The fixed current most stepper drivers use is > only because they don't know where they are in the DQ frame. So they > provide a ton of D and shaft error shifts the angle to produce some Q. > > If that's the case a closed loop stepper system is still interesting. However, I've had a shorter mail discussion with Zapp about their products and the given arguments and statements out rule them totally as a provider for me. He started a debate about how bad it is to build a machine and a retrofit is much better - without knowing a thing about my engineering skills, profession or previous experience in machine construction (please find a machine which is suitable for a five axis retrofit). Right now I'm leaning towards servo's after all. ------------------------------------------------------------------------------ Get 100% visibility into Java/.NET code with AppDynamics Lite! It's a free troubleshooting tool designed for production. Get down to code-level detail for bottlenecks, with <2% overhead. Download for free and get started troubleshooting in minutes. http://pubads.g.doubleclick.net/gampad/clk?id=48897031&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
